Beta

- Move data_navigator, json_converter, merge, and path_parser to pkg/yqlib
- Extract yamlToString from yq to pkg/yqlib/yaml_converter
- Move utils_test to test/utils

.gitignore

@@ -23,6 +23,7 @@ _cgo_export.*
 
 _testmain.go
 coverage.out
+coverage.html
 *.exe
 *.test
 *.prof

README.md

@@ -43,7 +43,7 @@ sudo apt install yq -y
 ```
 ### or, [Download latest binary](https://github.com/mikefarah/yq/releases/latest) or alternatively:
 ```
-GO111MODULE=on go get github.com/mikefarah/yq@2.4.1
+GO111MODULE=on go get github.com/mikefarah/yq/v2
 ```
 
 ## Run with Docker

Upgrade Notes

@@ -0,0 +1,56 @@
+
+# New Features
+  - Keeps yaml comments and formatting (string blocks are saved, number formatting is preserved, so it won't drop off trailing 0s for values like 0.10, which is important when that's a version entry )
+  
+  - Handles anchors! (doc link)
+  - Can specify yaml tags (e.g. !!int), quoting values no longer sufficient, need to specify the tag value instead.
+  - Can print out matching paths and values when splatting (doc link)
+  - JSON output works for all commands! Yaml files with multiple documents are printed out as one JSON document per line. 
+  - Deep splat (**) to match arbitrary paths, (doc link)
+
+
+# Breaking changes
+
+## Update scripts file format has changed to be more powerful. 
+Comments can be added, and delete commands have been introduced.
+
+## Reading and splatting, matching results are printed once per line.
+  e.g:
+
+```json
+parent:
+  childA: 
+    no: matches here
+  childB:
+    there: matches
+    hi: no match
+    there2: also matches
+```
+
+yq r sample.yaml 'parent.*.there*'
+
+old
+```yaml
+- null
+- - matches
+  - also matches
+```
+
+new
+```yaml
+matches
+also matches
+```
+
+and you can print the matching paths:
+
+yq r --printMode pv sample.yaml 'parent.*.there*'
+
+```yaml
+parent.childB.there: matches
+parent.childB.there2: also matches
+```
+
+# Merge command
+- New flag 'autocreates' missing entries in target by default, new flag to turn that off.
+

compare.sh

@@ -0,0 +1,13 @@
+GREEN='\033[0;32m'
+NC='\033[0m'
+
+echo "${GREEN}---Old---${NC}"
+yq $@ > /tmp/yq-old-output
+cat /tmp/yq-old-output
+
+echo "${GREEN}---New---${NC}"
+./yq $@ > /tmp/yq-new-output
+cat /tmp/yq-new-output
+
+echo "${GREEN}---Diff---${NC}"
+colordiff /tmp/yq-old-output /tmp/yq-new-output

data_navigator.go

@@ -1,349 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"reflect"
-	"strconv"
-	"strings"
-
-	yaml "github.com/mikefarah/yaml/v2"
-)
-
-func matchesKey(key string, actual interface{}) bool {
-	var actualString = fmt.Sprintf("%v", actual)
-	var prefixMatch = strings.TrimSuffix(key, "*")
-	if prefixMatch != key {
-		return strings.HasPrefix(actualString, prefixMatch)
-	}
-	return actualString == key
-}
-
-func entriesInSlice(context yaml.MapSlice, key string) []*yaml.MapItem {
-	var matches = make([]*yaml.MapItem, 0)
-	for idx := range context {
-		var entry = &context[idx]
-		if matchesKey(key, entry.Key) {
-			matches = append(matches, entry)
-		}
-	}
-	return matches
-}
-
-func getMapSlice(context interface{}) yaml.MapSlice {
-	var mapSlice yaml.MapSlice
-	switch context := context.(type) {
-	case yaml.MapSlice:
-		mapSlice = context
-	default:
-		mapSlice = make(yaml.MapSlice, 0)
-	}
-	return mapSlice
-}
-
-func getArray(context interface{}) (array []interface{}, ok bool) {
-	switch context := context.(type) {
-	case []interface{}:
-		array = context
-		ok = true
-	default:
-		array = make([]interface{}, 0)
-		ok = false
-	}
-	return
-}
-
-func writeMap(context interface{}, paths []string, value interface{}) interface{} {
-	log.Debugf("writeMap with path %v for %v to set value %v\n", paths, context, value)
-
-	mapSlice := getMapSlice(context)
-
-	if len(paths) == 0 {
-		return context
-	}
-
-	children := entriesInSlice(mapSlice, paths[0])
-
-	if len(children) == 0 && paths[0] == "*" {
-		log.Debugf("\tNo matches, return map as is")
-		return context
-	}
-
-	if len(children) == 0 {
-		newChild := yaml.MapItem{Key: paths[0]}
-		mapSlice = append(mapSlice, newChild)
-		children = entriesInSlice(mapSlice, paths[0])
-		log.Debugf("\tAppended child at %v for mapSlice %v\n", paths[0], mapSlice)
-	}
-
-	remainingPaths := paths[1:]
-	for _, child := range children {
-		child.Value = updatedChildValue(child.Value, remainingPaths, value)
-	}
-	log.Debugf("\tReturning mapSlice %v\n", mapSlice)
-	return mapSlice
-}
-
-func updatedChildValue(child interface{}, remainingPaths []string, value interface{}) interface{} {
-	if len(remainingPaths) == 0 {
-		return value
-	}
-	log.Debugf("updatedChildValue for child %v with path %v to set value %v", child, remainingPaths, value)
-	log.Debugf("type of child is %v", reflect.TypeOf(child))
-
-	switch child := child.(type) {
-	case nil:
-		if remainingPaths[0] == "+" || remainingPaths[0] == "*" {
-			return writeArray(child, remainingPaths, value)
-		}
-	case []interface{}:
-		_, nextIndexErr := strconv.ParseInt(remainingPaths[0], 10, 64)
-		arrayCommand := nextIndexErr == nil || remainingPaths[0] == "+" || remainingPaths[0] == "*"
-		if arrayCommand {
-			return writeArray(child, remainingPaths, value)
-		}
-	}
-	return writeMap(child, remainingPaths, value)
-}
-
-func writeArray(context interface{}, paths []string, value interface{}) []interface{} {
-	log.Debugf("writeArray with path %v for %v to set value %v\n", paths, context, value)
-	array, _ := getArray(context)
-
-	if len(paths) == 0 {
-		return array
-	}
-
-	log.Debugf("\tarray %v\n", array)
-
-	rawIndex := paths[0]
-	remainingPaths := paths[1:]
-	var index int64
-	// the append array indicator
-	if rawIndex == "+" {
-		index = int64(len(array))
-	} else if rawIndex == "*" {
-		for index, oldChild := range array {
-			array[index] = updatedChildValue(oldChild, remainingPaths, value)
-		}
-		return array
-	} else {
-		index, _ = strconv.ParseInt(rawIndex, 10, 64) // nolint
-		// writeArray is only called by updatedChildValue which handles parsing the
-		// index, as such this renders this dead code.
-	}
-
-	for index >= int64(len(array)) {
-		array = append(array, nil)
-	}
-	currentChild := array[index]
-
-	log.Debugf("\tcurrentChild %v\n", currentChild)
-
-	array[index] = updatedChildValue(currentChild, remainingPaths, value)
-	log.Debugf("\tReturning array %v\n", array)
-	return array
-}
-
-func readMap(context yaml.MapSlice, head string, tail []string) (interface{}, error) {
-	log.Debugf("readingMap %v with key %v\n", context, head)
-	if head == "*" {
-		return readMapSplat(context, tail)
-	}
-
-	entries := entriesInSlice(context, head)
-	if len(entries) == 1 {
-		return calculateValue(entries[0].Value, tail)
-	} else if len(entries) == 0 {
-		return nil, nil
-	}
-	var errInIdx error
-	values := make([]interface{}, len(entries))
-	for idx, entry := range entries {
-		values[idx], errInIdx = calculateValue(entry.Value, tail)
-		if errInIdx != nil {
-			log.Errorf("Error updating index %v in %v", idx, context)
-			return nil, errInIdx
-		}
-
-	}
-	return values, nil
-}
-
-func readMapSplat(context yaml.MapSlice, tail []string) (interface{}, error) {
-	var newArray = make([]interface{}, len(context))
-	var i = 0
-	for _, entry := range context {
-		if len(tail) > 0 {
-			val, err := recurse(entry.Value, tail[0], tail[1:])
-			if err != nil {
-				return nil, err
-			}
-			newArray[i] = val
-		} else {
-			newArray[i] = entry.Value
-		}
-		i++
-	}
-	return newArray, nil
-}
-
-func recurse(value interface{}, head string, tail []string) (interface{}, error) {
-	switch value := value.(type) {
-	case []interface{}:
-		if head == "*" {
-			return readArraySplat(value, tail)
-		}
-		index, err := strconv.ParseInt(head, 10, 64)
-		if err != nil {
-			return nil, fmt.Errorf("error accessing array: %v", err)
-		}
-		return readArray(value, index, tail)
-	case yaml.MapSlice:
-		return readMap(value, head, tail)
-	default:
-		return nil, nil
-	}
-}
-
-func readArray(array []interface{}, head int64, tail []string) (interface{}, error) {
-	if head >= int64(len(array)) {
-		return nil, nil
-	}
-
-	value := array[head]
-	return calculateValue(value, tail)
-}
-
-func readArraySplat(array []interface{}, tail []string) (interface{}, error) {
-	var newArray = make([]interface{}, len(array))
-	for index, value := range array {
-		val, err := calculateValue(value, tail)
-		if err != nil {
-			return nil, err
-		}
-		newArray[index] = val
-	}
-	return newArray, nil
-}
-
-func calculateValue(value interface{}, tail []string) (interface{}, error) {
-	if len(tail) > 0 {
-		return recurse(value, tail[0], tail[1:])
-	}
-	return value, nil
-}
-
-func deleteMap(context interface{}, paths []string) (yaml.MapSlice, error) {
-	log.Debugf("deleteMap for %v for %v\n", paths, context)
-
-	mapSlice := getMapSlice(context)
-
-	if len(paths) == 0 {
-		return mapSlice, nil
-	}
-
-	var index int
-	var child yaml.MapItem
-	for index, child = range mapSlice {
-		if matchesKey(paths[0], child.Key) {
-			log.Debugf("\tMatched [%v] with [%v] at index %v", paths[0], child.Key, index)
-			var badDelete error
-			mapSlice, badDelete = deleteEntryInMap(mapSlice, child, index, paths)
-			if badDelete != nil {
-				return nil, badDelete
-			}
-		}
-	}
-
-	return mapSlice, nil
-
-}
-
-func deleteEntryInMap(original yaml.MapSlice, child yaml.MapItem, index int, paths []string) (yaml.MapSlice, error) {
-	remainingPaths := paths[1:]
-
-	var newSlice yaml.MapSlice
-	if len(remainingPaths) > 0 {
-		newChild := yaml.MapItem{Key: child.Key}
-		var errorDeleting error
-		newChild.Value, errorDeleting = deleteChildValue(child.Value, remainingPaths)
-		if errorDeleting != nil {
-			return nil, errorDeleting
-		}
-
-		newSlice = make(yaml.MapSlice, len(original))
-		for i := range original {
-			item := original[i]
-			if i == index {
-				item = newChild
-			}
-			newSlice[i] = item
-		}
-	} else {
-		// Delete item from slice at index
-		newSlice = append(original[:index], original[index+1:]...)
-		log.Debugf("\tDeleted item index %d from original", index)
-	}
-
-	log.Debugf("\tReturning original %v\n", original)
-	return newSlice, nil
-}
-
-func deleteArraySplat(array []interface{}, tail []string) (interface{}, error) {
-	log.Debugf("deleteArraySplat for %v for %v\n", tail, array)
-	var newArray = make([]interface{}, len(array))
-	for index, value := range array {
-		val, err := deleteChildValue(value, tail)
-		if err != nil {
-			return nil, err
-		}
-		newArray[index] = val
-	}
-	return newArray, nil
-}
-
-func deleteArray(array []interface{}, paths []string, index int64) (interface{}, error) {
-	log.Debugf("deleteArray for %v for %v\n", paths, array)
-
-	if index >= int64(len(array)) {
-		return array, nil
-	}
-
-	remainingPaths := paths[1:]
-	if len(remainingPaths) > 0 {
-		// Recurse into the array element at index
-		var errorDeleting error
-		array[index], errorDeleting = deleteMap(array[index], remainingPaths)
-		if errorDeleting != nil {
-			return nil, errorDeleting
-		}
-
-	} else {
-		// Delete the array element at index
-		array = append(array[:index], array[index+1:]...)
-		log.Debugf("\tDeleted item index %d from array, leaving %v", index, array)
-	}
-
-	log.Debugf("\tReturning array: %v\n", array)
-	return array, nil
-}
-
-func deleteChildValue(child interface{}, remainingPaths []string) (interface{}, error) {
-	log.Debugf("deleteChildValue for %v for %v\n", remainingPaths, child)
-	var head = remainingPaths[0]
-	var tail = remainingPaths[1:]
-	switch child := child.(type) {
-	case yaml.MapSlice:
-		return deleteMap(child, remainingPaths)
-	case []interface{}:
-		if head == "*" {
-			return deleteArraySplat(child, tail)
-		}
-		index, err := strconv.ParseInt(head, 10, 64)
-		if err != nil {
-			return nil, fmt.Errorf("error accessing array: %v", err)
-		}
-		return deleteArray(child, remainingPaths, index)
-	}
-	return child, nil
-}

data_navigator_test.go

@@ -1,399 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"sort"
-	"testing"
-)
-
-func TestReadMap_simple(t *testing.T) {
-	var data = parseData(`
----
-b:
-  c: 2
-`)
-	got, _ := readMap(data, "b", []string{"c"})
-	assertResult(t, 2, got)
-}
-
-func TestReadMap_numberKey(t *testing.T) {
-	var data = parseData(`
----
-200: things
-`)
-	got, _ := readMap(data, "200", []string{})
-	assertResult(t, "things", got)
-}
-
-func TestReadMap_splat(t *testing.T) {
-	var data = parseData(`
----
-mapSplat:
-  item1: things
-  item2: whatever
-  otherThing: cat
-`)
-	res, _ := readMap(data, "mapSplat", []string{"*"})
-	assertResult(t, "[things whatever cat]", fmt.Sprintf("%v", res))
-}
-
-func TestReadMap_prefixSplat(t *testing.T) {
-	var data = parseData(`
----
-mapSplat:
-  item1: things
-  item2: whatever
-  otherThing: cat
-`)
-	res, _ := readMap(data, "mapSplat", []string{"item*"})
-	assertResult(t, "[things whatever]", fmt.Sprintf("%v", res))
-}
-
-func TestReadMap_deep_splat(t *testing.T) {
-	var data = parseData(`
----
-mapSplatDeep:
-  item1:
-    cats: bananas
-  item2:
-    cats: apples
-`)
-
-	res, _ := readMap(data, "mapSplatDeep", []string{"*", "cats"})
-	result := res.([]interface{})
-	var actual = []string{result[0].(string), result[1].(string)}
-	sort.Strings(actual)
-	assertResult(t, "[apples bananas]", fmt.Sprintf("%v", actual))
-}
-
-func TestReadMap_key_doesnt_exist(t *testing.T) {
-	var data = parseData(`
----
-b:
-  c: 2
-`)
-	got, _ := readMap(data, "b.x.f", []string{"c"})
-	assertResult(t, nil, got)
-}
-
-func TestReadMap_recurse_against_string(t *testing.T) {
-	var data = parseData(`
----
-a: cat
-`)
-	got, _ := readMap(data, "a", []string{"b"})
-	assertResult(t, nil, got)
-}
-
-func TestReadMap_with_array(t *testing.T) {
-	var data = parseData(`
----
-b:
-  d:
-    - 3
-    - 4
-`)
-	got, _ := readMap(data, "b", []string{"d", "1"})
-	assertResult(t, 4, got)
-}
-
-func TestReadMap_with_array_and_bad_index(t *testing.T) {
-	var data = parseData(`
----
-b:
-  d:
-    - 3
-    - 4
-`)
-	_, err := readMap(data, "b", []string{"d", "x"})
-	if err == nil {
-		t.Fatal("Expected error due to invalid path")
-	}
-	expectedOutput := `error accessing array: strconv.ParseInt: parsing "x": invalid syntax`
-	assertResult(t, expectedOutput, err.Error())
-}
-
-func TestReadMap_with_mapsplat_array_and_bad_index(t *testing.T) {
-	var data = parseData(`
----
-b:
-  d:
-    e:
-      - 3
-      - 4
-    f:
-      - 1
-      - 2
-`)
-	_, err := readMap(data, "b", []string{"d", "*", "x"})
-	if err == nil {
-		t.Fatal("Expected error due to invalid path")
-	}
-	expectedOutput := `error accessing array: strconv.ParseInt: parsing "x": invalid syntax`
-	assertResult(t, expectedOutput, err.Error())
-}
-
-func TestReadMap_with_arraysplat_map_array_and_bad_index(t *testing.T) {
-	var data = parseData(`
----
-b:
-  d:
-    - names:
-        - fred
-        - smith
-    - names:
-        - sam
-        - bo
-`)
-	_, err := readMap(data, "b", []string{"d", "*", "names", "x"})
-	if err == nil {
-		t.Fatal("Expected error due to invalid path")
-	}
-	expectedOutput := `error accessing array: strconv.ParseInt: parsing "x": invalid syntax`
-	assertResult(t, expectedOutput, err.Error())
-}
-
-func TestReadMap_with_array_out_of_bounds(t *testing.T) {
-	var data = parseData(`
----
-b:
-  d:
-    - 3
-    - 4
-`)
-	got, _ := readMap(data, "b", []string{"d", "3"})
-	assertResult(t, nil, got)
-}
-
-func TestReadMap_with_array_out_of_bounds_by_1(t *testing.T) {
-	var data = parseData(`
----
-b:
-  d:
-    - 3
-    - 4
-`)
-	got, _ := readMap(data, "b", []string{"d", "2"})
-	assertResult(t, nil, got)
-}
-
-func TestReadMap_with_array_splat(t *testing.T) {
-	var data = parseData(`
-e:
-  -
-    name: Fred
-    thing: cat
-  -
-    name: Sam
-    thing: dog
-`)
-	got, _ := readMap(data, "e", []string{"*", "name"})
-	assertResult(t, "[Fred Sam]", fmt.Sprintf("%v", got))
-}
-
-func TestWrite_really_simple(t *testing.T) {
-	var data = parseData(`
-    b: 2
-`)
-
-	updated := writeMap(data, []string{"b"}, "4")
-	assertResult(t, "[{b 4}]", fmt.Sprintf("%v", updated))
-}
-
-func TestWrite_simple(t *testing.T) {
-	var data = parseData(`
-b:
-  c: 2
-`)
-
-	updated := writeMap(data, []string{"b", "c"}, "4")
-	assertResult(t, "[{b [{c 4}]}]", fmt.Sprintf("%v", updated))
-}
-
-func TestWrite_new(t *testing.T) {
-	var data = parseData(`
-b:
-  c: 2
-`)
-
-	updated := writeMap(data, []string{"b", "d"}, "4")
-	assertResult(t, "[{b [{c 2} {d 4}]}]", fmt.Sprintf("%v", updated))
-}
-
-func TestWrite_new_deep(t *testing.T) {
-	var data = parseData(`
-b:
-  c: 2
-`)
-
-	updated := writeMap(data, []string{"b", "d", "f"}, "4")
-	assertResult(t, "[{b [{c 2} {d [{f 4}]}]}]", fmt.Sprintf("%v", updated))
-}
-
-func TestWrite_array(t *testing.T) {
-	var data = parseData(`
-b:
-  - aa
-`)
-
-	updated := writeMap(data, []string{"b", "0"}, "bb")
-
-	assertResult(t, "[{b [bb]}]", fmt.Sprintf("%v", updated))
-}
-
-func TestWrite_new_array(t *testing.T) {
-	var data = parseData(`
-b:
-  c: 2
-`)
-
-	updated := writeMap(data, []string{"b", "0"}, "4")
-	assertResult(t, "[{b [{c 2} {0 4}]}]", fmt.Sprintf("%v", updated))
-}
-
-func TestWrite_new_array_deep(t *testing.T) {
-	var data = parseData(`
-a: apple
-`)
-
-	var expected = `a: apple
-b:
-- c: "4"`
-
-	updated := writeMap(data, []string{"b", "+", "c"}, "4")
-	got, _ := yamlToString(updated)
-	assertResult(t, expected, got)
-}
-
-func TestWrite_new_map_array_deep(t *testing.T) {
-	var data = parseData(`
-b:
-  c: 2
-`)
-	var expected = `b:
-  c: 2
-  d:
-  - "4"`
-
-	updated := writeMap(data, []string{"b", "d", "+"}, "4")
-	got, _ := yamlToString(updated)
-	assertResult(t, expected, got)
-}
-
-func TestWrite_add_to_array(t *testing.T) {
-	var data = parseData(`
-b:
-  - aa
-`)
-
-	var expected = `b:
-- aa
-- bb`
-
-	updated := writeMap(data, []string{"b", "1"}, "bb")
-	got, _ := yamlToString(updated)
-	assertResult(t, expected, got)
-}
-
-func TestWrite_with_no_tail(t *testing.T) {
-	var data = parseData(`
-b:
-  c: 2
-`)
-	updated := writeMap(data, []string{"b"}, "4")
-
-	assertResult(t, "[{b 4}]", fmt.Sprintf("%v", updated))
-}
-
-func TestWriteMap_no_paths(t *testing.T) {
-	var data = parseData(`
-b: 5
-`)
-
-	result := writeMap(data, []string{}, 4)
-	assertResult(t, fmt.Sprintf("%v", data), fmt.Sprintf("%v", result))
-}
-
-func TestWriteArray_no_paths(t *testing.T) {
-	var data = make([]interface{}, 1)
-	data[0] = "mike"
-	result := writeArray(data, []string{}, 4)
-	assertResult(t, fmt.Sprintf("%v", data), fmt.Sprintf("%v", result))
-}
-
-func TestDelete_MapItem(t *testing.T) {
-	var data = parseData(`
-a: 123
-b: 456
-`)
-	var expected = parseData(`
-b: 456
-`)
-
-	result, _ := deleteMap(data, []string{"a"})
-	assertResult(t, fmt.Sprintf("%v", expected), fmt.Sprintf("%v", result))
-}
-
-// Ensure deleting an index into a string does nothing
-func TestDelete_index_to_string(t *testing.T) {
-	var data = parseData(`
-a: mystring
-`)
-	result, _ := deleteMap(data, []string{"a", "0"})
-	assertResult(t, fmt.Sprintf("%v", data), fmt.Sprintf("%v", result))
-}
-
-func TestDelete_list_index(t *testing.T) {
-	var data = parseData(`
-a: [3, 4]
-`)
-	var expected = parseData(`
-a: [3]
-`)
-	result, _ := deleteMap(data, []string{"a", "1"})
-	assertResult(t, fmt.Sprintf("%v", expected), fmt.Sprintf("%v", result))
-}
-
-func TestDelete_list_index_beyond_bounds(t *testing.T) {
-	var data = parseData(`
-a: [3, 4]
-`)
-	result, _ := deleteMap(data, []string{"a", "5"})
-	assertResult(t, fmt.Sprintf("%v", data), fmt.Sprintf("%v", result))
-}
-
-func TestDelete_list_index_out_of_bounds_by_1(t *testing.T) {
-	var data = parseData(`
-a: [3, 4]
-`)
-	result, _ := deleteMap(data, []string{"a", "2"})
-	assertResult(t, fmt.Sprintf("%v", data), fmt.Sprintf("%v", result))
-}
-
-func TestDelete_no_paths(t *testing.T) {
-	var data = parseData(`
-a: [3, 4]
-b:
-  - name: test
-`)
-	result, _ := deleteMap(data, []string{})
-	assertResult(t, fmt.Sprintf("%v", data), fmt.Sprintf("%v", result))
-}
-
-func TestDelete_array_map_item(t *testing.T) {
-	var data = parseData(`
-b:
-- name: fred
-  value: blah
-- name: john
-  value: test
-`)
-	var expected = parseData(`
-b:
-- value: blah
-- name: john
-  value: test
-`)
-	result, _ := deleteMap(data, []string{"b", "0", "name"})
-	assertResult(t, fmt.Sprintf("%v", expected), fmt.Sprintf("%v", result))
-}

examples/array.yaml

@@ -7,3 +7,5 @@
     - lala
     - land
   serial: 1
+- become: false
+  gather_facts: true

examples/data1.yaml

@@ -1,2 +1,4 @@
-a: simple
+a: simple # just the best
 b: [1, 2]
+c:
+  test: 1

examples/data2.yaml

@@ -1,4 +1,7 @@
-a: other
+a: other # better than the original
 b: [3, 4]
 c:
+  toast: leave
   test: 1
+  tell: 1
+  taco: cool

examples/instruction_sample.yaml

@@ -1,2 +1,10 @@
-b.c: cat
-b.e[+].name: Mike Farah
+- command: update 
+  path: b.c
+  value:
+    #great 
+    things: frog # wow!
+- command: update
+  path: b.e[+].name
+  value: Mike Farah
+- command: delete
+  path: b.d

examples/merge-anchor.yaml

@@ -0,0 +1,19 @@
+foo: &foo
+  a: original
+  thing: coolasdf
+  thirsty: yep
+
+bar: &bar
+  b: 2
+  thing: coconut
+  c: oldbar
+
+foobarList:
+  <<: [*foo,*bar]
+  c: newbar
+
+foobar:
+  <<: *foo
+  thirty: well beyond
+  thing: ice
+  c: 3

examples/sample.yaml

@@ -1,7 +1,7 @@
-a: Easy! as one two three
+a: true
 b:
   c: 2
-  d: [3, 4]
+  d: [3, 4, 5]
   e:
     - name: fred
       value: 3

examples/sample2.yaml

@@ -1,9 +1,2 @@
-a: Easy! as one two three
 b:
   c: things
-  d: whatever
-things:
- thing1:
-  cat: 'fred'
- thing2:
-  cat: 'sam'

examples/sample_array_2.yaml

@@ -1 +1,2 @@
-[4,5]
+- 4
+- 5

examples/simple-anchor.yaml

@@ -0,0 +1,4 @@
+foo: &foo
+  a: 1
+
+foobar: *foo

go.mod

@@ -1,12 +1,13 @@
-module github.com/mikefarah/yq/v2
+module github.com/mikefarah/yq/v3
 
 require (
-	github.com/mikefarah/yaml/v2 v2.4.0
+	github.com/mikefarah/yaml/v2 v2.4.0 // indirect
 	github.com/pkg/errors v0.8.1
 	github.com/spf13/cobra v0.0.5
-	golang.org/x/tools v0.0.0-20191030203535-5e247c9ad0a0 // indirect
-	gopkg.in/imdario/mergo.v0 v0.3.7
+	golang.org/x/tools v0.0.0-20191213221258-04c2e8eff935 // indirect
+	gopkg.in/imdario/mergo.v0 v0.3.7 // indirect
 	gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473
+	gopkg.in/yaml.v3 v3.0.0-20191120175047-4206685974f2
 )
 
 go 1.13

go.sum

@@ -10,8 +10,11 @@ github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T
 github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
+github.com/mikefarah/yaml v2.1.0+incompatible h1:nu2cqmzk4WlWJNgnevY88faMcdrDzYGcsUjYFxEpB7Y=
 github.com/mikefarah/yaml/v2 v2.4.0 h1:eYqfooY0BnvKTJxr7+ABJs13n3dg9n347GScDaU2Lww=
 github.com/mikefarah/yaml/v2 v2.4.0/go.mod h1:ahVqZF4n1W4NqwvVnZzC4es67xsW9uR/RRf2RRxieJU=
+github.com/mikefarah/yq v2.4.0+incompatible h1:oBxbWy8R9hI3BIUUxEf0CzikWa2AgnGrGhvGQt5jgjk=
+github.com/mikefarah/yq/v2 v2.4.1 h1:tajDonaFK6WqitSZExB6fKlWQy/yCkptqxh2AXEe3N4=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
@@ -32,14 +35,21 @@ github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljT
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20181205085412-a5c9d58dba9a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20191030203535-5e247c9ad0a0 h1:s5lp4ug7qHzUccgyFdjsX7OZDzHXRaePrF3B3vmUiuM=
 golang.org/x/tools v0.0.0-20191030203535-5e247c9ad0a0/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20191213221258-04c2e8eff935 h1:kJQZhwFzSwJS2BxboKjdZzWczQOZx8VuH7Y8hhuGUtM=
+golang.org/x/tools v0.0.0-20191213221258-04c2e8eff935/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/imdario/mergo.v0 v0.3.7 h1:QDotlIZtaO/p+Um0ok18HRTpq5i5/SAk/qprsor+9c8=
@@ -48,3 +58,5 @@ gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473 h1:6D+BvnJ/j6e222UW
 gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473/go.mod h1:N1eN2tsCx0Ydtgjl4cqmbRCsY4/+z4cYDeqwZTk6zog=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v3 v3.0.0-20191120175047-4206685974f2 h1:XZx7nhd5GMaZpmDaEHFVafUZC7ya0fuo7cSJ3UCKYmM=
+gopkg.in/yaml.v3 v3.0.0-20191120175047-4206685974f2/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

json_converter.go

@@ -1,44 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"fmt"
-	"strconv"
-
-	yaml "github.com/mikefarah/yaml/v2"
-)
-
-func jsonToString(context interface{}) (string, error) {
-	out, err := json.Marshal(toJSON(context))
-	if err != nil {
-		return "", fmt.Errorf("error printing yaml as json: %v", err)
-	}
-	return string(out), nil
-}
-
-func toJSON(context interface{}) interface{} {
-	switch context := context.(type) {
-	case []interface{}:
-		oldArray := context
-		newArray := make([]interface{}, len(oldArray))
-		for index, value := range oldArray {
-			newArray[index] = toJSON(value)
-		}
-		return newArray
-	case yaml.MapSlice:
-		oldMap := context
-		newMap := make(map[string]interface{})
-		for _, entry := range oldMap {
-			if str, ok := entry.Key.(string); ok {
-				newMap[str] = toJSON(entry.Value)
-			} else if i, ok := entry.Key.(int); ok {
-				newMap[strconv.Itoa(i)] = toJSON(entry.Value)
-			} else if b, ok := entry.Key.(bool); ok {
-				newMap[strconv.FormatBool(b)] = toJSON(entry.Value)
-			}
-		}
-		return newMap
-	default:
-		return context
-	}
-}

json_converter_test.go

@@ -1,46 +0,0 @@
-package main
-
-import (
-	"testing"
-)
-
-func TestJsonToString(t *testing.T) {
-	var data = parseData(`
----
-b:
-  c: 2
-`)
-	got, _ := jsonToString(data)
-	assertResult(t, "{\"b\":{\"c\":2}}", got)
-}
-
-func TestJsonToString_withIntKey(t *testing.T) {
-	var data = parseData(`
----
-b:
-  2: c
-`)
-	got, _ := jsonToString(data)
-	assertResult(t, `{"b":{"2":"c"}}`, got)
-}
-
-func TestJsonToString_withBoolKey(t *testing.T) {
-	var data = parseData(`
----
-b:
-  false: c
-`)
-	got, _ := jsonToString(data)
-	assertResult(t, `{"b":{"false":"c"}}`, got)
-}
-
-func TestJsonToString_withArray(t *testing.T) {
-	var data = parseData(`
----
-b:
-  - item: one
-  - item: two
-`)
-	got, _ := jsonToString(data)
-	assertResult(t, "{\"b\":[{\"item\":\"one\"},{\"item\":\"two\"}]}", got)
-}

merge.go

@@ -1,12 +0,0 @@
-package main
-
-import mergo "gopkg.in/imdario/mergo.v0"
-
-func merge(dst interface{}, src interface{}, overwrite bool, append bool) error {
-	if overwrite {
-		return mergo.Merge(dst, src, mergo.WithOverride)
-	} else if append {
-		return mergo.Merge(dst, src, mergo.WithAppendSlice)
-	}
-	return mergo.Merge(dst, src)
-}

path_parser.go

@@ -1,55 +0,0 @@
-package main
-
-func parsePath(path string) []string {
-	return parsePathAccum([]string{}, path)
-}
-
-func parsePathAccum(paths []string, remaining string) []string {
-	head, tail := nextYamlPath(remaining)
-	if tail == "" {
-		return append(paths, head)
-	}
-	return parsePathAccum(append(paths, head), tail)
-}
-
-func nextYamlPath(path string) (pathElement string, remaining string) {
-	switch path[0] {
-	case '[':
-		// e.g [0].blah.cat -> we need to return "0" and "blah.cat"
-		return search(path[1:], []uint8{']'}, true)
-	case '"':
-		// e.g "a.b".blah.cat -> we need to return "a.b" and "blah.cat"
-		return search(path[1:], []uint8{'"'}, true)
-	default:
-		// e.g "a.blah.cat" -> return "a" and "blah.cat"
-		return search(path[0:], []uint8{'.', '['}, false)
-	}
-}
-
-func search(path string, matchingChars []uint8, skipNext bool) (pathElement string, remaining string) {
-	for i := 0; i < len(path); i++ {
-		var char = path[i]
-		if contains(matchingChars, char) {
-			var remainingStart = i + 1
-			if skipNext {
-				remainingStart = remainingStart + 1
-			} else if !skipNext && char != '.' {
-				remainingStart = i
-			}
-			if remainingStart > len(path) {
-				remainingStart = len(path)
-			}
-			return path[0:i], path[remainingStart:]
-		}
-	}
-	return path, ""
-}
-
-func contains(matchingChars []uint8, candidate uint8) bool {
-	for _, a := range matchingChars {
-		if a == candidate {
-			return true
-		}
-	}
-	return false
-}

path_parser_test.go

@@ -1,43 +0,0 @@
-package main
-
-import (
-	"testing"
-)
-
-var parsePathsTests = []struct {
-	path          string
-	expectedPaths []string
-}{
-	{"a.b", []string{"a", "b"}},
-	{"a.b[0]", []string{"a", "b", "0"}},
-	{"a.b.d[+]", []string{"a", "b", "d", "+"}},
-}
-
-func TestParsePath(t *testing.T) {
-	for _, tt := range parsePathsTests {
-		assertResultComplex(t, tt.expectedPaths, parsePath(tt.path))
-	}
-}
-
-var nextYamlPathTests = []struct {
-	path              string
-	expectedElement   string
-	expectedRemaining string
-}{
-	{"a.b", "a", "b"},
-	{"a", "a", ""},
-	{"a.b.c", "a", "b.c"},
-	{"\"a.b\".c", "a.b", "c"},
-	{"a.\"b.c\".d", "a", "\"b.c\".d"},
-	{"[1].a.d", "1", "a.d"},
-	{"a[0].c", "a", "[0].c"},
-	{"[0]", "0", ""},
-}
-
-func TestNextYamlPath(t *testing.T) {
-	for _, tt := range nextYamlPathTests {
-		var element, remaining = nextYamlPath(tt.path)
-		assertResultWithContext(t, tt.expectedElement, element, tt)
-		assertResultWithContext(t, tt.expectedRemaining, remaining, tt)
-	}
-}

pkg/yqlib/data_navigator.go

@@ -0,0 +1,245 @@
+package yqlib
+
+import (
+	"strconv"
+
+	errors "github.com/pkg/errors"
+	yaml "gopkg.in/yaml.v3"
+)
+
+type DataNavigator interface {
+	Traverse(value *yaml.Node, path []string) error
+}
+
+type navigator struct {
+	navigationStrategy NavigationStrategy
+}
+
+func NewDataNavigator(NavigationStrategy NavigationStrategy) DataNavigator {
+	return &navigator{
+		navigationStrategy: NavigationStrategy,
+	}
+}
+
+func (n *navigator) Traverse(value *yaml.Node, path []string) error {
+	realValue := value
+	emptyArray := make([]interface{}, 0)
+	if realValue.Kind == yaml.DocumentNode {
+		log.Debugf("its a document! returning the first child")
+		return n.doTraverse(value.Content[0], "", path, emptyArray)
+	}
+	return n.doTraverse(value, "", path, emptyArray)
+}
+
+func (n *navigator) doTraverse(value *yaml.Node, head string, tail []string, pathStack []interface{}) error {
+	log.Debug("head %v", head)
+	DebugNode(value)
+	var errorDeepSplatting error
+	if head == "**" && value.Kind != yaml.ScalarNode {
+		errorDeepSplatting = n.recurse(value, head, tail, pathStack)
+		// ignore errors here, we are deep splatting so we may accidently give a string key
+		// to an array sequence
+		if len(tail) > 0 {
+			_ = n.recurse(value, tail[0], tail[1:], pathStack)
+		}
+		return errorDeepSplatting
+	}
+
+	if len(tail) > 0 {
+		log.Debugf("diving into %v", tail[0])
+		DebugNode(value)
+		return n.recurse(value, tail[0], tail[1:], pathStack)
+	}
+	return n.navigationStrategy.Visit(NewNodeContext(value, head, tail, pathStack))
+}
+
+func (n *navigator) getOrReplace(original *yaml.Node, expectedKind yaml.Kind) *yaml.Node {
+	if original.Kind != expectedKind {
+		log.Debug("wanted %v but it was %v, overriding", expectedKind, original.Kind)
+		return &yaml.Node{Kind: expectedKind}
+	}
+	return original
+}
+
+func (n *navigator) recurse(value *yaml.Node, head string, tail []string, pathStack []interface{}) error {
+	log.Debug("recursing, processing %v", head)
+	switch value.Kind {
+	case yaml.MappingNode:
+		log.Debug("its a map with %v entries", len(value.Content)/2)
+		return n.recurseMap(value, head, tail, pathStack)
+	case yaml.SequenceNode:
+		log.Debug("its a sequence of %v things!", len(value.Content))
+		if head == "*" || head == "**" {
+			return n.splatArray(value, head, tail, pathStack)
+		} else if head == "+" {
+			return n.appendArray(value, head, tail, pathStack)
+		}
+		return n.recurseArray(value, head, tail, pathStack)
+	case yaml.AliasNode:
+		log.Debug("its an alias!")
+		DebugNode(value.Alias)
+		if n.navigationStrategy.FollowAlias(NewNodeContext(value, head, tail, pathStack)) {
+			log.Debug("following the alias")
+			return n.recurse(value.Alias, head, tail, pathStack)
+		}
+		return nil
+	default:
+		return nil
+	}
+}
+
+func (n *navigator) recurseMap(value *yaml.Node, head string, tail []string, pathStack []interface{}) error {
+	traversedEntry := false
+	errorVisiting := n.visitMatchingEntries(value, head, tail, pathStack, func(contents []*yaml.Node, indexInMap int) error {
+		log.Debug("recurseMap: visitMatchingEntries")
+		n.navigationStrategy.DebugVisitedNodes()
+		newPathStack := append(pathStack, contents[indexInMap].Value)
+		log.Debug("appended %v", contents[indexInMap].Value)
+		n.navigationStrategy.DebugVisitedNodes()
+		log.Debug("should I traverse? %v, %v", head, pathStackToString(newPathStack))
+		DebugNode(value)
+		if n.navigationStrategy.ShouldTraverse(NewNodeContext(contents[indexInMap+1], head, tail, newPathStack), contents[indexInMap].Value) {
+			log.Debug("recurseMap: Going to traverse")
+			traversedEntry = true
+			// contents[indexInMap+1] = n.getOrReplace(contents[indexInMap+1], guessKind(head, tail, contents[indexInMap+1].Kind))
+			errorTraversing := n.doTraverse(contents[indexInMap+1], head, tail, newPathStack)
+			log.Debug("recurseMap: Finished traversing")
+			n.navigationStrategy.DebugVisitedNodes()
+			return errorTraversing
+		} else {
+			log.Debug("nope not traversing")
+		}
+		return nil
+	})
+
+	if errorVisiting != nil {
+		return errorVisiting
+	}
+
+	if traversedEntry || head == "*" || head == "**" || !n.navigationStrategy.AutoCreateMap(NewNodeContext(value, head, tail, pathStack)) {
+		return nil
+	}
+
+	mapEntryKey := yaml.Node{Value: head, Kind: yaml.ScalarNode}
+	value.Content = append(value.Content, &mapEntryKey)
+	mapEntryValue := yaml.Node{Kind: guessKind(head, tail, 0)}
+	value.Content = append(value.Content, &mapEntryValue)
+	log.Debug("adding new node %v", head)
+	return n.doTraverse(&mapEntryValue, head, tail, append(pathStack, head))
+}
+
+// need to pass the node in, as it may be aliased
+type mapVisitorFn func(contents []*yaml.Node, index int) error
+
+func (n *navigator) visitDirectMatchingEntries(node *yaml.Node, head string, tail []string, pathStack []interface{}, visit mapVisitorFn) error {
+	var contents = node.Content
+	for index := 0; index < len(contents); index = index + 2 {
+		content := contents[index]
+
+		log.Debug("index %v, checking %v, %v", index, content.Value, content.Tag)
+		n.navigationStrategy.DebugVisitedNodes()
+		errorVisiting := visit(contents, index)
+		if errorVisiting != nil {
+			return errorVisiting
+		}
+	}
+	return nil
+}
+
+func (n *navigator) visitMatchingEntries(node *yaml.Node, head string, tail []string, pathStack []interface{}, visit mapVisitorFn) error {
+	var contents = node.Content
+	log.Debug("visitMatchingEntries %v", head)
+	DebugNode(node)
+	// value.Content is a concatenated array of key, value,
+	// so keys are in the even indexes, values in odd.
+	// merge aliases are defined first, but we only want to traverse them
+	// if we don't find a match directly on this node first.
+	errorVisitedDirectEntries := n.visitDirectMatchingEntries(node, head, tail, pathStack, visit)
+
+	if errorVisitedDirectEntries != nil || !n.navigationStrategy.FollowAlias(NewNodeContext(node, head, tail, pathStack)) {
+		return errorVisitedDirectEntries
+	}
+	return n.visitAliases(contents, head, tail, pathStack, visit)
+}
+
+func (n *navigator) visitAliases(contents []*yaml.Node, head string, tail []string, pathStack []interface{}, visit mapVisitorFn) error {
+	// merge aliases are defined first, but we only want to traverse them
+	// if we don't find a match on this node first.
+	// traverse them backwards so that the last alias overrides the preceding.
+	// a node can either be
+	// an alias to one other node (e.g. <<: *blah)
+	// or a sequence of aliases   (e.g. <<: [*blah, *foo])
+	log.Debug("checking for aliases")
+	for index := len(contents) - 2; index >= 0; index = index - 2 {
+
+		if contents[index+1].Kind == yaml.AliasNode {
+			valueNode := contents[index+1]
+			log.Debug("found an alias")
+			DebugNode(contents[index])
+			DebugNode(valueNode)
+
+			errorInAlias := n.visitMatchingEntries(valueNode.Alias, head, tail, pathStack, visit)
+			if errorInAlias != nil {
+				return errorInAlias
+			}
+		} else if contents[index+1].Kind == yaml.SequenceNode {
+			// could be an array of aliases...
+			errorVisitingAliasSeq := n.visitAliasSequence(contents[index+1].Content, head, tail, pathStack, visit)
+			if errorVisitingAliasSeq != nil {
+				return errorVisitingAliasSeq
+			}
+		}
+	}
+	return nil
+}
+
+func (n *navigator) visitAliasSequence(possibleAliasArray []*yaml.Node, head string, tail []string, pathStack []interface{}, visit mapVisitorFn) error {
+	// need to search this backwards too, so that aliases defined last override the preceding.
+	for aliasIndex := len(possibleAliasArray) - 1; aliasIndex >= 0; aliasIndex = aliasIndex - 1 {
+		child := possibleAliasArray[aliasIndex]
+		if child.Kind == yaml.AliasNode {
+			log.Debug("found an alias")
+			DebugNode(child)
+			errorInAlias := n.visitMatchingEntries(child.Alias, head, tail, pathStack, visit)
+			if errorInAlias != nil {
+				return errorInAlias
+			}
+		}
+	}
+	return nil
+}
+
+func (n *navigator) splatArray(value *yaml.Node, head string, tail []string, pathStack []interface{}) error {
+	for index, childValue := range value.Content {
+		log.Debug("processing")
+		DebugNode(childValue)
+		childValue = n.getOrReplace(childValue, guessKind(head, tail, childValue.Kind))
+		var err = n.doTraverse(childValue, head, tail, append(pathStack, index))
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (n *navigator) appendArray(value *yaml.Node, head string, tail []string, pathStack []interface{}) error {
+	var newNode = yaml.Node{Kind: guessKind(head, tail, 0)}
+	value.Content = append(value.Content, &newNode)
+	log.Debug("appending a new node, %v", value.Content)
+	return n.doTraverse(&newNode, head, tail, append(pathStack, len(value.Content)-1))
+}
+
+func (n *navigator) recurseArray(value *yaml.Node, head string, tail []string, pathStack []interface{}) error {
+	var index, err = strconv.ParseInt(head, 10, 64) // nolint
+	if err != nil {
+		return errors.Wrapf(err, "Error parsing array index '%v' for '%v'", head, pathStackToString(pathStack))
+	}
+
+	for int64(len(value.Content)) <= index {
+		value.Content = append(value.Content, &yaml.Node{Kind: guessKind(head, tail, 0)})
+	}
+
+	value.Content[index] = n.getOrReplace(value.Content[index], guessKind(head, tail, value.Content[index].Kind))
+
+	return n.doTraverse(value.Content[index], head, tail, append(pathStack, index))
+}

pkg/yqlib/data_navigator_test.go

@@ -0,0 +1 @@
+package yqlib

pkg/yqlib/delete_navigation_strategy.go

@@ -0,0 +1,66 @@
+package yqlib
+
+import (
+	"strconv"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+func DeleteNavigationStrategy(pathElementToDelete string) NavigationStrategy {
+	parser := NewPathParser()
+	return &NavigationStrategyImpl{
+		visitedNodes: []*NodeContext{},
+		followAlias: func(nodeContext NodeContext) bool {
+			return false
+		},
+		autoCreateMap: func(nodeContext NodeContext) bool {
+			return true
+		},
+		visit: func(nodeContext NodeContext) error {
+			node := nodeContext.Node
+			log.Debug("need to find and delete %v in here", pathElementToDelete)
+			DebugNode(node)
+			if node.Kind == yaml.SequenceNode {
+				newContent, errorDeleting := deleteFromArray(node.Content, pathElementToDelete)
+				if errorDeleting != nil {
+					return errorDeleting
+				}
+				node.Content = newContent
+			} else if node.Kind == yaml.MappingNode {
+				node.Content = deleteFromMap(parser, node.Content, nodeContext.PathStack, pathElementToDelete)
+			}
+			return nil
+		},
+	}
+}
+func deleteFromMap(pathParser PathParser, contents []*yaml.Node, pathStack []interface{}, pathElementToDelete string) []*yaml.Node {
+	newContents := make([]*yaml.Node, 0)
+	for index := 0; index < len(contents); index = index + 2 {
+		keyNode := contents[index]
+		valueNode := contents[index+1]
+		if !pathParser.MatchesNextPathElement(NewNodeContext(keyNode, pathElementToDelete, []string{}, pathStack), keyNode.Value) {
+			log.Debug("adding node %v", keyNode.Value)
+			newContents = append(newContents, keyNode, valueNode)
+		} else {
+			log.Debug("skipping node %v", keyNode.Value)
+		}
+	}
+	return newContents
+}
+
+func deleteFromArray(content []*yaml.Node, pathElementToDelete string) ([]*yaml.Node, error) {
+
+	if pathElementToDelete == "*" {
+		return make([]*yaml.Node, 0), nil
+	}
+
+	var index, err = strconv.ParseInt(pathElementToDelete, 10, 64) // nolint
+	if err != nil {
+		return content, err
+	}
+	if index >= int64(len(content)) {
+		log.Debug("index %v is greater than content length %v", index, len(content))
+		return content, nil
+	}
+	return append(content[:index], content[index+1:]...), nil
+}

pkg/yqlib/encoder.go

@@ -0,0 +1,44 @@
+package yqlib
+
+import (
+	"encoding/json"
+	"io"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+type Encoder interface {
+	Encode(node *yaml.Node) error
+}
+
+type yamlEncoder struct {
+	encoder *yaml.Encoder
+}
+
+func NewYamlEncoder(destination io.Writer) Encoder {
+	var encoder = yaml.NewEncoder(destination)
+	encoder.SetIndent(2)
+	return &yamlEncoder{encoder}
+}
+
+func (ye *yamlEncoder) Encode(node *yaml.Node) error {
+	return ye.encoder.Encode(node)
+}
+
+type jsonEncoder struct {
+	encoder *json.Encoder
+}
+
+func NewJsonEncoder(destination io.Writer) Encoder {
+	var encoder = json.NewEncoder(destination)
+	return &jsonEncoder{encoder}
+}
+
+func (je *jsonEncoder) Encode(node *yaml.Node) error {
+	var dataBucket interface{}
+	errorDecoding := node.Decode(&dataBucket)
+	if errorDecoding != nil {
+		return errorDecoding
+	}
+	return je.encoder.Encode(dataBucket)
+}

pkg/yqlib/lib.go

@@ -0,0 +1,148 @@
+package yqlib
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+	"strings"
+
+	logging "gopkg.in/op/go-logging.v1"
+	yaml "gopkg.in/yaml.v3"
+)
+
+var log = logging.MustGetLogger("yq")
+
+type UpdateCommand struct {
+	Command   string
+	Path      string
+	Value     *yaml.Node
+	Overwrite bool
+}
+
+func DebugNode(value *yaml.Node) {
+	if value == nil {
+		log.Debug("-- node is nil --")
+	} else if log.IsEnabledFor(logging.DEBUG) {
+		buf := new(bytes.Buffer)
+		encoder := yaml.NewEncoder(buf)
+		errorEncoding := encoder.Encode(value)
+		if errorEncoding != nil {
+			log.Error("Error debugging node, %v", errorEncoding.Error())
+		}
+		encoder.Close()
+		log.Debug("Tag: %v", value.Tag)
+		log.Debug("%v", buf.String())
+	}
+}
+
+func pathStackToString(pathStack []interface{}) string {
+	return mergePathStackToString(pathStack, false)
+}
+
+func mergePathStackToString(pathStack []interface{}, appendArrays bool) string {
+	var sb strings.Builder
+	for index, path := range pathStack {
+		switch path.(type) {
+		case int:
+			if appendArrays {
+				sb.WriteString("[+]")
+			} else {
+				sb.WriteString(fmt.Sprintf("[%v]", path))
+			}
+
+		default:
+			sb.WriteString(fmt.Sprintf("%v", path))
+		}
+
+		if index < len(pathStack)-1 {
+			sb.WriteString(".")
+		}
+	}
+	return sb.String()
+}
+
+func guessKind(head string, tail []string, guess yaml.Kind) yaml.Kind {
+	log.Debug("tail %v", tail)
+	if len(tail) == 0 && guess == 0 {
+		log.Debug("end of path, must be a scalar")
+		return yaml.ScalarNode
+	} else if len(tail) == 0 {
+		return guess
+	}
+
+	var _, errorParsingInt = strconv.ParseInt(tail[0], 10, 64)
+	if tail[0] == "+" || errorParsingInt == nil {
+		return yaml.SequenceNode
+	}
+	if (tail[0] == "*" || tail[0] == "**" || head == "**") && (guess == yaml.SequenceNode || guess == yaml.MappingNode) {
+		return guess
+	}
+	if guess == yaml.AliasNode {
+		log.Debug("guess was an alias, okey doke.")
+		return guess
+	}
+	log.Debug("forcing a mapping node")
+	log.Debug("yaml.SequenceNode %v", guess == yaml.SequenceNode)
+	log.Debug("yaml.ScalarNode %v", guess == yaml.ScalarNode)
+	return yaml.MappingNode
+}
+
+type YqLib interface {
+	Get(rootNode *yaml.Node, path string) ([]*NodeContext, error)
+	Update(rootNode *yaml.Node, updateCommand UpdateCommand, autoCreate bool) error
+	New(path string) yaml.Node
+
+	PathStackToString(pathStack []interface{}) string
+	MergePathStackToString(pathStack []interface{}, appendArrays bool) string
+}
+
+type lib struct {
+	parser PathParser
+}
+
+func NewYqLib() YqLib {
+	return &lib{
+		parser: NewPathParser(),
+	}
+}
+
+func (l *lib) Get(rootNode *yaml.Node, path string) ([]*NodeContext, error) {
+	var paths = l.parser.ParsePath(path)
+	NavigationStrategy := ReadNavigationStrategy()
+	navigator := NewDataNavigator(NavigationStrategy)
+	error := navigator.Traverse(rootNode, paths)
+	return NavigationStrategy.GetVisitedNodes(), error
+
+}
+
+func (l *lib) PathStackToString(pathStack []interface{}) string {
+	return pathStackToString(pathStack)
+}
+
+func (l *lib) MergePathStackToString(pathStack []interface{}, appendArrays bool) string {
+	return mergePathStackToString(pathStack, appendArrays)
+}
+
+func (l *lib) New(path string) yaml.Node {
+	var paths = l.parser.ParsePath(path)
+	newNode := yaml.Node{Kind: guessKind("", paths, 0)}
+	return newNode
+}
+
+func (l *lib) Update(rootNode *yaml.Node, updateCommand UpdateCommand, autoCreate bool) error {
+	log.Debugf("%v to %v", updateCommand.Command, updateCommand.Path)
+	switch updateCommand.Command {
+	case "update":
+		var paths = l.parser.ParsePath(updateCommand.Path)
+		navigator := NewDataNavigator(UpdateNavigationStrategy(updateCommand, autoCreate))
+		return navigator.Traverse(rootNode, paths)
+	case "delete":
+		var paths = l.parser.ParsePath(updateCommand.Path)
+		lastBit, newTail := paths[len(paths)-1], paths[:len(paths)-1]
+		navigator := NewDataNavigator(DeleteNavigationStrategy(lastBit))
+		return navigator.Traverse(rootNode, newTail)
+	default:
+		return fmt.Errorf("Unknown command %v", updateCommand.Command)
+	}
+
+}

pkg/yqlib/lib_test.go

@@ -0,0 +1,176 @@
+package yqlib
+
+import (
+	"testing"
+
+	"github.com/mikefarah/yq/v3/test"
+)
+
+func TestLib(t *testing.T) {
+
+	subject := NewYqLib()
+
+	t.Run("PathStackToString_Empty", func(t *testing.T) {
+		emptyArray := make([]interface{}, 0)
+		got := subject.PathStackToString(emptyArray)
+		test.AssertResult(t, ``, got)
+	})
+
+	t.Run("PathStackToString", func(t *testing.T) {
+		array := make([]interface{}, 3)
+		array[0] = "a"
+		array[1] = 0
+		array[2] = "b"
+		got := subject.PathStackToString(array)
+		test.AssertResult(t, `a.[0].b`, got)
+	})
+
+	t.Run("MergePathStackToString", func(t *testing.T) {
+		array := make([]interface{}, 3)
+		array[0] = "a"
+		array[1] = 0
+		array[2] = "b"
+		got := subject.MergePathStackToString(array, true)
+		test.AssertResult(t, `a.[+].b`, got)
+	})
+
+	// 	t.Run("TestReadPath_WithError", func(t *testing.T) {
+	// 		var data = test.ParseData(`
+	// ---
+	// b:
+	//   - c
+	// `)
+
+	// 		_, err := subject.ReadPath(data, "b.[a]")
+	// 		if err == nil {
+	// 			t.Fatal("Expected error due to invalid path")
+	// 		}
+	// 	})
+
+	// 	t.Run("TestWritePath", func(t *testing.T) {
+	// 		var data = test.ParseData(`
+	// ---
+	// b:
+	//   2: c
+	// `)
+
+	// 		got := subject.WritePath(data, "b.3", "a")
+	// 		test.AssertResult(t, `[{b [{2 c} {3 a}]}]`, fmt.Sprintf("%v", got))
+	// 	})
+
+	// 	t.Run("TestPrefixPath", func(t *testing.T) {
+	// 		var data = test.ParseData(`
+	// ---
+	// b:
+	//   2: c
+	// `)
+
+	// 		got := subject.PrefixPath(data, "a.d")
+	// 		test.AssertResult(t, `[{a [{d [{b [{2 c}]}]}]}]`, fmt.Sprintf("%v", got))
+	// 	})
+
+	// 	t.Run("TestDeletePath", func(t *testing.T) {
+	// 		var data = test.ParseData(`
+	// ---
+	// b:
+	//   2: c
+	//   3: a
+	// `)
+
+	// 		got, _ := subject.DeletePath(data, "b.2")
+	// 		test.AssertResult(t, `[{b [{3 a}]}]`, fmt.Sprintf("%v", got))
+	// 	})
+
+	// 	t.Run("TestDeletePath_WithError", func(t *testing.T) {
+	// 		var data = test.ParseData(`
+	// ---
+	// b:
+	//   - c
+	// `)
+
+	// 		_, err := subject.DeletePath(data, "b.[a]")
+	// 		if err == nil {
+	// 			t.Fatal("Expected error due to invalid path")
+	// 		}
+	// 	})
+
+	// 	t.Run("TestMerge", func(t *testing.T) {
+	// 		var dst = test.ParseData(`
+	// ---
+	// a: b
+	// c: d
+	// `)
+	// 		var src = test.ParseData(`
+	// ---
+	// a: 1
+	// b: 2
+	// `)
+
+	// 		var mergedData = make(map[interface{}]interface{})
+	// 		mergedData["root"] = dst
+	// 		var mapDataBucket = make(map[interface{}]interface{})
+	// 		mapDataBucket["root"] = src
+
+	// 		err := subject.Merge(&mergedData, mapDataBucket, false, false)
+	// 		if err != nil {
+	// 			t.Fatal("Unexpected error")
+	// 		}
+	// 		test.AssertResult(t, `[{a b} {c d}]`, fmt.Sprintf("%v", mergedData["root"]))
+	// 	})
+
+	// 	t.Run("TestMerge_WithOverwrite", func(t *testing.T) {
+	// 		var dst = test.ParseData(`
+	// ---
+	// a: b
+	// c: d
+	// `)
+	// 		var src = test.ParseData(`
+	// ---
+	// a: 1
+	// b: 2
+	// `)
+
+	// 		var mergedData = make(map[interface{}]interface{})
+	// 		mergedData["root"] = dst
+	// 		var mapDataBucket = make(map[interface{}]interface{})
+	// 		mapDataBucket["root"] = src
+
+	// 		err := subject.Merge(&mergedData, mapDataBucket, true, false)
+	// 		if err != nil {
+	// 			t.Fatal("Unexpected error")
+	// 		}
+	// 		test.AssertResult(t, `[{a 1} {b 2}]`, fmt.Sprintf("%v", mergedData["root"]))
+	// 	})
+
+	// 	t.Run("TestMerge_WithAppend", func(t *testing.T) {
+	// 		var dst = test.ParseData(`
+	// ---
+	// a: b
+	// c: d
+	// `)
+	// 		var src = test.ParseData(`
+	// ---
+	// a: 1
+	// b: 2
+	// `)
+
+	// 		var mergedData = make(map[interface{}]interface{})
+	// 		mergedData["root"] = dst
+	// 		var mapDataBucket = make(map[interface{}]interface{})
+	// 		mapDataBucket["root"] = src
+
+	// 		err := subject.Merge(&mergedData, mapDataBucket, false, true)
+	// 		if err != nil {
+	// 			t.Fatal("Unexpected error")
+	// 		}
+	// 		test.AssertResult(t, `[{a b} {c d} {a 1} {b 2}]`, fmt.Sprintf("%v", mergedData["root"]))
+	// 	})
+
+	// 	t.Run("TestMerge_WithError", func(t *testing.T) {
+	// 		err := subject.Merge(nil, nil, false, false)
+	// 		if err == nil {
+	// 			t.Fatal("Expected error due to nil")
+	// 		}
+	// 	})
+
+}

pkg/yqlib/navigation_strategy.go

@@ -0,0 +1,148 @@
+package yqlib
+
+import (
+	"fmt"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+type NodeContext struct {
+	Node      *yaml.Node
+	Head      string
+	Tail      []string
+	PathStack []interface{}
+}
+
+func NewNodeContext(node *yaml.Node, head string, tail []string, pathStack []interface{}) NodeContext {
+	newTail := make([]string, len(tail))
+	copy(newTail, tail)
+
+	newPathStack := make([]interface{}, len(pathStack))
+	copy(newPathStack, pathStack)
+	return NodeContext{
+		Node:      node,
+		Head:      head,
+		Tail:      newTail,
+		PathStack: newPathStack,
+	}
+}
+
+type NavigationStrategy interface {
+	FollowAlias(nodeContext NodeContext) bool
+	AutoCreateMap(nodeContext NodeContext) bool
+	Visit(nodeContext NodeContext) error
+	// node key is the string value of the last element in the path stack
+	// we use it to match against the pathExpression in head.
+	ShouldTraverse(nodeContext NodeContext, nodeKey string) bool
+	GetVisitedNodes() []*NodeContext
+	DebugVisitedNodes()
+}
+
+type NavigationStrategyImpl struct {
+	followAlias   func(nodeContext NodeContext) bool
+	autoCreateMap func(nodeContext NodeContext) bool
+	visit         func(nodeContext NodeContext) error
+	visitedNodes  []*NodeContext
+}
+
+func (ns *NavigationStrategyImpl) GetVisitedNodes() []*NodeContext {
+	return ns.visitedNodes
+}
+
+func (ns *NavigationStrategyImpl) FollowAlias(nodeContext NodeContext) bool {
+	return ns.followAlias(nodeContext)
+}
+
+func (ns *NavigationStrategyImpl) AutoCreateMap(nodeContext NodeContext) bool {
+	return ns.autoCreateMap(nodeContext)
+}
+
+func (ns *NavigationStrategyImpl) ShouldTraverse(nodeContext NodeContext, nodeKey string) bool {
+	// we should traverse aliases (if enabled), but not visit them :/
+	if len(nodeContext.PathStack) == 0 {
+		return true
+	}
+
+	if ns.alreadyVisited(nodeContext.PathStack) {
+		return false
+	}
+
+	parser := NewPathParser()
+
+	return (nodeKey == "<<" && ns.FollowAlias(nodeContext)) || (nodeKey != "<<" &&
+		parser.MatchesNextPathElement(nodeContext, nodeKey))
+}
+
+func (ns *NavigationStrategyImpl) shouldVisit(nodeContext NodeContext) bool {
+	pathStack := nodeContext.PathStack
+	if len(pathStack) == 0 {
+		return true
+	}
+	log.Debug("tail len %v", len(nodeContext.Tail))
+	// SOMETHING HERE!
+
+	if ns.alreadyVisited(pathStack) || len(nodeContext.Tail) != 0 {
+		return false
+	}
+
+	nodeKey := fmt.Sprintf("%v", pathStack[len(pathStack)-1])
+	log.Debug("nodeKey: %v, nodeContext.Head: %v", nodeKey, nodeContext.Head)
+	parser := NewPathParser()
+
+	// only visit aliases if its an exact match
+	return (nodeKey == "<<" && nodeContext.Head == "<<") || (nodeKey != "<<" &&
+		parser.MatchesNextPathElement(nodeContext, nodeKey))
+}
+
+func (ns *NavigationStrategyImpl) Visit(nodeContext NodeContext) error {
+	log.Debug("Visit?, %v, %v", nodeContext.Head, pathStackToString(nodeContext.PathStack))
+	DebugNode(nodeContext.Node)
+	if ns.shouldVisit(nodeContext) {
+		log.Debug("yep, visiting")
+		//  pathStack array must be
+		// copied, as append() may sometimes reuse and modify the array
+		ns.visitedNodes = append(ns.visitedNodes, &nodeContext)
+		ns.DebugVisitedNodes()
+		return ns.visit(nodeContext)
+	}
+	log.Debug("nope, skip it")
+	return nil
+}
+
+func (ns *NavigationStrategyImpl) DebugVisitedNodes() {
+	log.Debug("Visited Nodes:")
+	for _, candidate := range ns.visitedNodes {
+		log.Debug(" - %v", pathStackToString(candidate.PathStack))
+	}
+}
+
+func (ns *NavigationStrategyImpl) alreadyVisited(pathStack []interface{}) bool {
+	log.Debug("checking already visited pathStack: %v", pathStackToString(pathStack))
+	for _, candidate := range ns.visitedNodes {
+		candidatePathStack := candidate.PathStack
+		if patchStacksMatch(candidatePathStack, pathStack) {
+			log.Debug("paths match, already seen it")
+			return true
+		}
+
+	}
+	log.Debug("never seen it before!")
+	return false
+}
+
+func patchStacksMatch(path1 []interface{}, path2 []interface{}) bool {
+	log.Debug("checking against path: %v", pathStackToString(path1))
+
+	if len(path1) != len(path2) {
+		return false
+	}
+	for index, p1Value := range path1 {
+
+		p2Value := path2[index]
+		if p1Value != p2Value {
+			return false
+		}
+	}
+	return true
+
+}

pkg/yqlib/path_parser.go

@@ -0,0 +1,101 @@
+package yqlib
+
+import (
+	"strconv"
+	"strings"
+)
+
+type PathParser interface {
+	ParsePath(path string) []string
+	MatchesNextPathElement(nodeContext NodeContext, nodeKey string) bool
+}
+
+type pathParser struct{}
+
+func NewPathParser() PathParser {
+	return &pathParser{}
+}
+
+/**
+ * node: node that we may traverse/visit
+ * head: path element expression to match against
+ * tail: remaining path element expressions
+ * pathStack: stack of actual paths we've matched to get to node
+ * nodeKey: actual value of this nodes 'key' or index.
+ */
+func (p *pathParser) MatchesNextPathElement(nodeContext NodeContext, nodeKey string) bool {
+	head := nodeContext.Head
+	if head == "**" || head == "*" {
+		return true
+	}
+	if head == "+" {
+		log.Debug("head is +, nodeKey is %v", nodeKey)
+		var _, err = strconv.ParseInt(nodeKey, 10, 64) // nolint
+		if err == nil {
+			return true
+		}
+	}
+	var prefixMatch = strings.TrimSuffix(head, "*")
+	if prefixMatch != head {
+		log.Debug("prefix match, %v", strings.HasPrefix(nodeKey, prefixMatch))
+		return strings.HasPrefix(nodeKey, prefixMatch)
+	}
+	return nodeKey == head
+}
+
+func (p *pathParser) ParsePath(path string) []string {
+	if path == "" {
+		return []string{}
+	}
+	return p.parsePathAccum([]string{}, path)
+}
+
+func (p *pathParser) parsePathAccum(paths []string, remaining string) []string {
+	head, tail := p.nextYamlPath(remaining)
+	if tail == "" {
+		return append(paths, head)
+	}
+	return p.parsePathAccum(append(paths, head), tail)
+}
+
+func (p *pathParser) nextYamlPath(path string) (pathElement string, remaining string) {
+	switch path[0] {
+	case '[':
+		// e.g [0].blah.cat -> we need to return "0" and "blah.cat"
+		return p.search(path[1:], []uint8{']'}, true)
+	case '"':
+		// e.g "a.b".blah.cat -> we need to return "a.b" and "blah.cat"
+		return p.search(path[1:], []uint8{'"'}, true)
+	default:
+		// e.g "a.blah.cat" -> return "a" and "blah.cat"
+		return p.search(path[0:], []uint8{'.', '['}, false)
+	}
+}
+
+func (p *pathParser) search(path string, matchingChars []uint8, skipNext bool) (pathElement string, remaining string) {
+	for i := 0; i < len(path); i++ {
+		var char = path[i]
+		if p.contains(matchingChars, char) {
+			var remainingStart = i + 1
+			if skipNext {
+				remainingStart = remainingStart + 1
+			} else if !skipNext && char != '.' {
+				remainingStart = i
+			}
+			if remainingStart > len(path) {
+				remainingStart = len(path)
+			}
+			return path[0:i], path[remainingStart:]
+		}
+	}
+	return path, ""
+}
+
+func (p *pathParser) contains(matchingChars []uint8, candidate uint8) bool {
+	for _, a := range matchingChars {
+		if a == candidate {
+			return true
+		}
+	}
+	return false
+}

pkg/yqlib/path_parser_test.go

@@ -0,0 +1,78 @@
+package yqlib
+
+import (
+	"testing"
+
+	"github.com/mikefarah/yq/v3/test"
+)
+
+var parser = NewPathParser()
+
+var parsePathsTests = []struct {
+	path          string
+	expectedPaths []string
+}{
+	{"a.b", []string{"a", "b"}},
+	{"a.b.**", []string{"a", "b", "**"}},
+	{"a.b.*", []string{"a", "b", "*"}},
+	{"a.b[0]", []string{"a", "b", "0"}},
+	{"a.b.d[+]", []string{"a", "b", "d", "+"}},
+	{"a", []string{"a"}},
+	{"a.b.c", []string{"a", "b", "c"}},
+	{"\"a.b\".c", []string{"a.b", "c"}},
+	{"a.\"b.c\".d", []string{"a", "b.c", "d"}},
+	{"[1].a.d", []string{"1", "a", "d"}},
+	{"a[0].c", []string{"a", "0", "c"}},
+	{"[0]", []string{"0"}},
+}
+
+func TestPathParserParsePath(t *testing.T) {
+	for _, tt := range parsePathsTests {
+		test.AssertResultComplex(t, tt.expectedPaths, parser.ParsePath(tt.path))
+	}
+}
+
+func TestPathParserMatchesNextPathElementSplat(t *testing.T) {
+	var node = NodeContext{Head: "*"}
+	test.AssertResult(t, true, parser.MatchesNextPathElement(node, ""))
+}
+
+func TestPathParserMatchesNextPathElementDeepSplat(t *testing.T) {
+	var node = NodeContext{Head: "**"}
+	test.AssertResult(t, true, parser.MatchesNextPathElement(node, ""))
+}
+
+func TestPathParserMatchesNextPathElementAppendArrayValid(t *testing.T) {
+	var node = NodeContext{Head: "+"}
+	test.AssertResult(t, true, parser.MatchesNextPathElement(node, "3"))
+}
+
+func TestPathParserMatchesNextPathElementAppendArrayInvalid(t *testing.T) {
+	var node = NodeContext{Head: "+"}
+	test.AssertResult(t, false, parser.MatchesNextPathElement(node, "cat"))
+}
+
+func TestPathParserMatchesNextPathElementPrefixMatchesWhole(t *testing.T) {
+	var node = NodeContext{Head: "cat*"}
+	test.AssertResult(t, true, parser.MatchesNextPathElement(node, "cat"))
+}
+
+func TestPathParserMatchesNextPathElementPrefixMatchesStart(t *testing.T) {
+	var node = NodeContext{Head: "cat*"}
+	test.AssertResult(t, true, parser.MatchesNextPathElement(node, "caterpillar"))
+}
+
+func TestPathParserMatchesNextPathElementPrefixMismatch(t *testing.T) {
+	var node = NodeContext{Head: "cat*"}
+	test.AssertResult(t, false, parser.MatchesNextPathElement(node, "dog"))
+}
+
+func TestPathParserMatchesNextPathElementExactMatch(t *testing.T) {
+	var node = NodeContext{Head: "farahtek"}
+	test.AssertResult(t, true, parser.MatchesNextPathElement(node, "farahtek"))
+}
+
+func TestPathParserMatchesNextPathElementExactMismatch(t *testing.T) {
+	var node = NodeContext{Head: "farahtek"}
+	test.AssertResult(t, false, parser.MatchesNextPathElement(node, "othertek"))
+}

pkg/yqlib/read_navigation_strategy.go

@@ -0,0 +1,16 @@
+package yqlib
+
+func ReadNavigationStrategy() NavigationStrategy {
+	return &NavigationStrategyImpl{
+		visitedNodes: []*NodeContext{},
+		followAlias: func(nodeContext NodeContext) bool {
+			return true
+		},
+		autoCreateMap: func(nodeContext NodeContext) bool {
+			return false
+		},
+		visit: func(nodeContext NodeContext) error {
+			return nil
+		},
+	}
+}

pkg/yqlib/update_navigation_strategy.go

@@ -0,0 +1,34 @@
+package yqlib
+
+func UpdateNavigationStrategy(updateCommand UpdateCommand, autoCreate bool) NavigationStrategy {
+	return &NavigationStrategyImpl{
+		visitedNodes: []*NodeContext{},
+		followAlias: func(nodeContext NodeContext) bool {
+			return false
+		},
+		autoCreateMap: func(nodeContext NodeContext) bool {
+			return autoCreate
+		},
+		visit: func(nodeContext NodeContext) error {
+			node := nodeContext.Node
+			changesToApply := updateCommand.Value
+			if updateCommand.Overwrite || node.Value == "" {
+				log.Debug("going to update")
+				DebugNode(node)
+				log.Debug("with")
+				DebugNode(changesToApply)
+				node.Value = changesToApply.Value
+				node.Tag = changesToApply.Tag
+				node.Kind = changesToApply.Kind
+				node.Style = changesToApply.Style
+				node.Content = changesToApply.Content
+				node.HeadComment = changesToApply.HeadComment
+				node.LineComment = changesToApply.LineComment
+				node.FootComment = changesToApply.FootComment
+			} else {
+				log.Debug("skipping update as node already has value %v and overwriteFlag is ", node.Value, updateCommand.Overwrite)
+			}
+			return nil
+		},
+	}
+}

pkg/yqlib/value_parser.go

@@ -0,0 +1,47 @@
+package yqlib
+
+import (
+	"strconv"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+type ValueParser interface {
+	Parse(argument string, customTag string) *yaml.Node
+}
+
+type valueParser struct {
+}
+
+func NewValueParser() ValueParser {
+	return &valueParser{}
+}
+
+func (v *valueParser) Parse(argument string, customTag string) *yaml.Node {
+	var err interface{}
+	var tag = customTag
+
+	if tag == "" {
+		_, err = strconv.ParseBool(argument)
+		if err == nil {
+			tag = "!!bool"
+		}
+		_, err = strconv.ParseFloat(argument, 64)
+		if err == nil {
+			tag = "!!float"
+		}
+		_, err = strconv.ParseInt(argument, 10, 64)
+		if err == nil {
+			tag = "!!int"
+		}
+
+		if argument == "null" {
+			tag = "!!null"
+		}
+		if argument == "[]" {
+			return &yaml.Node{Tag: "!!seq", Kind: yaml.SequenceNode}
+		}
+	}
+	log.Debugf("parsed value '%v', tag: '%v'", argument, tag)
+	return &yaml.Node{Value: argument, Tag: tag, Kind: yaml.ScalarNode}
+}

pkg/yqlib/value_parser_test.go

@@ -0,0 +1,38 @@
+package yqlib
+
+import (
+	"testing"
+
+	"github.com/mikefarah/yq/v3/test"
+	yaml "gopkg.in/yaml.v3"
+)
+
+var parseValueTests = []struct {
+	argument        string
+	customTag       string
+	expectedTag     string
+	testDescription string
+}{
+	{"true", "", "!!bool", "boolean"},
+	{"true", "!!str", "!!str", "boolean forced as string"},
+	{"3.4", "", "!!float", "float"},
+	{"1212121", "", "!!int", "big number"},
+	{"1212121.1", "", "!!float", "big float number"},
+	{"3", "", "!!int", "int"},
+	{"null", "", "!!null", "null"},
+}
+
+func TestValueParserParse(t *testing.T) {
+	for _, tt := range parseValueTests {
+		actual := NewValueParser().Parse(tt.argument, tt.customTag)
+		test.AssertResultWithContext(t, tt.argument, actual.Value, tt.testDescription)
+		test.AssertResultWithContext(t, tt.expectedTag, actual.Tag, tt.testDescription)
+		test.AssertResult(t, yaml.ScalarNode, actual.Kind)
+	}
+}
+
+func TestValueParserParseEmptyArray(t *testing.T) {
+	actual := NewValueParser().Parse("[]", "")
+	test.AssertResult(t, "!!seq", actual.Tag)
+	test.AssertResult(t, yaml.SequenceNode, actual.Kind)
+}

scripts/coverage.sh

@@ -2,5 +2,5 @@
 
 set -e
 
-go test -coverprofile=coverage.out
-go tool cover -html=coverage.out -o cover/coverage.html
+go test -coverprofile=coverage.out -v $(go list ./... | grep -v -E 'examples' | grep -v -E 'test')
+go tool cover -html=coverage.out -o coverage.html

scripts/test.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
 
-go test -v $(go list ./... | grep -v -E 'examples')
+go test -v $(go list ./... | grep -v -E 'examples' | grep -v -E 'test')

snap/snapcraft.yaml

@@ -1,5 +1,5 @@
 name: yq
-version: '2.4.1'
+version: '3.0.0-beta'
 summary: A lightweight and portable command-line YAML processor
 description: |
   The aim of the project is to be the jq or sed of yaml files.

test.yml

@@ -1,2 +1,3 @@
-a: apple
-c: cat
+b:
+  c: thing
+  d: another thing

test/utils.go

@@ -1,4 +1,4 @@
-package main
+package test
 
 import (
 	"bytes"
@@ -9,8 +9,8 @@ import (
 	"strings"
 	"testing"
 
-	yaml "github.com/mikefarah/yaml/v2"
 	"github.com/spf13/cobra"
+	yaml "gopkg.in/yaml.v3"
 )
 
 type resulter struct {
@@ -19,7 +19,7 @@ type resulter struct {
 	Command *cobra.Command
 }
 
-func runCmd(c *cobra.Command, input string) resulter {
+func RunCmd(c *cobra.Command, input string) resulter {
 	buf := new(bytes.Buffer)
 	c.SetOutput(buf)
 	c.SetArgs(strings.Split(input, " "))
@@ -30,8 +30,8 @@ func runCmd(c *cobra.Command, input string) resulter {
 	return resulter{err, output, c}
 }
 
-func parseData(rawData string) yaml.MapSlice {
-	var parsedData yaml.MapSlice
+func ParseData(rawData string) yaml.Node {
+	var parsedData yaml.Node
 	err := yaml.Unmarshal([]byte(rawData), &parsedData)
 	if err != nil {
 		fmt.Printf("Error parsing yaml: %v\n", err)
@@ -40,21 +40,21 @@ func parseData(rawData string) yaml.MapSlice {
 	return parsedData
 }
 
-func assertResult(t *testing.T, expectedValue interface{}, actualValue interface{}) {
+func AssertResult(t *testing.T, expectedValue interface{}, actualValue interface{}) {
 	t.Helper()
 	if expectedValue != actualValue {
 		t.Error("Expected <", expectedValue, "> but got <", actualValue, ">", fmt.Sprintf("%T", actualValue))
 	}
 }
 
-func assertResultComplex(t *testing.T, expectedValue interface{}, actualValue interface{}) {
+func AssertResultComplex(t *testing.T, expectedValue interface{}, actualValue interface{}) {
 	t.Helper()
 	if !reflect.DeepEqual(expectedValue, actualValue) {
 		t.Error("Expected <", expectedValue, "> but got <", actualValue, ">", fmt.Sprintf("%T", actualValue))
 	}
 }
 
-func assertResultWithContext(t *testing.T, expectedValue interface{}, actualValue interface{}, context interface{}) {
+func AssertResultWithContext(t *testing.T, expectedValue interface{}, actualValue interface{}, context interface{}) {
 	t.Helper()
 	if expectedValue != actualValue {
 		t.Error(context)
@@ -62,7 +62,7 @@ func assertResultWithContext(t *testing.T, expectedValue interface{}, actualValu
 	}
 }
 
-func writeTempYamlFile(content string) string {
+func WriteTempYamlFile(content string) string {
 	tmpfile, _ := ioutil.TempFile("", "testyaml")
 	defer func() {
 		_ = tmpfile.Close()
@@ -72,11 +72,11 @@ func writeTempYamlFile(content string) string {
 	return tmpfile.Name()
 }
 
-func readTempYamlFile(name string) string {
+func ReadTempYamlFile(name string) string {
 	content, _ := ioutil.ReadFile(name)
 	return string(content)
 }
 
-func removeTempYamlFile(name string) {
+func RemoveTempYamlFile(name string) {
 	_ = os.Remove(name)
 }

version.go

@@ -11,12 +11,12 @@ var (
 	GitDescribe string
 
 	// Version is main version number that is being run at the moment.
-	Version = "2.4.1"
+	Version = "3.0.0"
 
 	// VersionPrerelease is a pre-release marker for the version. If this is "" (empty string)
 	// then it means that it is a final release. Otherwise, this is a pre-release
 	// such as "dev" (in development), "beta", "rc1", etc.
-	VersionPrerelease = ""
+	VersionPrerelease = "beta"
 )
 
 // ProductName is the name of the product

yq.go

@@ -6,28 +6,33 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	"reflect"
 	"strconv"
 	"strings"
 
+	"github.com/mikefarah/yq/v3/pkg/yqlib"
+
 	errors "github.com/pkg/errors"
 
-	yaml "github.com/mikefarah/yaml/v2"
 	"github.com/spf13/cobra"
 	logging "gopkg.in/op/go-logging.v1"
+	yaml "gopkg.in/yaml.v3"
 )
 
-var trimOutput = true
+var customTag = ""
+var printMode = "v"
 var writeInplace = false
 var writeScript = ""
 var outputToJSON = false
 var overwriteFlag = false
+var autoCreateFlag = true
 var allowEmptyFlag = false
 var appendFlag = false
 var verbose = false
 var version = false
 var docIndex = "0"
 var log = logging.MustGetLogger("yq")
+var lib = yqlib.NewYqLib()
+var valueParser = yqlib.NewValueParser()
 
 func main() {
 	cmd := newCommandCLI()
@@ -38,7 +43,6 @@ func main() {
 }
 
 func newCommandCLI() *cobra.Command {
-	yaml.DefaultMapType = reflect.TypeOf(yaml.MapSlice{})
 	var rootCmd = &cobra.Command{
 		Use:   "yq",
 		Short: "yq is a lightweight and portable command-line YAML processor.",
@@ -69,8 +73,8 @@ func newCommandCLI() *cobra.Command {
 		},
 	}
 
-	rootCmd.PersistentFlags().BoolVarP(&trimOutput, "trim", "t", true, "trim yaml output")
 	rootCmd.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "verbose mode")
+	rootCmd.PersistentFlags().BoolVarP(&outputToJSON, "tojson", "j", false, "output as json")
 	rootCmd.Flags().BoolVarP(&version, "version", "V", false, "Print version information and quit")
 
 	rootCmd.AddCommand(
@@ -95,15 +99,16 @@ func createReadCmd() *cobra.Command {
 yq read things.yaml a.b.c
 yq r - a.b.c (reads from stdin)
 yq r things.yaml a.*.c
-yq r -d1 things.yaml a.array[0].blah
-yq r things.yaml a.array[*].blah
-yq r -- things.yaml --key-starting-with-dashes
+yq r things.yaml a.**.c
+yq r -d1 things.yaml 'a.array[0].blah'
+yq r things.yaml 'a.array[*].blah'
+yq r -- things.yaml --key-starting-with-dashes.blah
       `,
 		Long: "Outputs the value of the given path in the yaml file to STDOUT",
 		RunE: readProperty,
 	}
 	cmdRead.PersistentFlags().StringVarP(&docIndex, "doc", "d", "0", "process document index number (0 based, * for all documents)")
-	cmdRead.PersistentFlags().BoolVarP(&outputToJSON, "tojson", "j", false, "output as json")
+	cmdRead.PersistentFlags().StringVarP(&printMode, "printMode", "p", "v", "print mode (v (values, default), p (paths), pv (path and value pairs)")
 	return cmdRead
 }
 
@@ -113,13 +118,17 @@ func createWriteCmd() *cobra.Command {
 		Aliases: []string{"w"},
 		Short:   "yq w [--inplace/-i] [--script/-s script_file] [--doc/-d index] sample.yaml a.b.c newValue",
 		Example: `
-yq write things.yaml a.b.c cat
+yq write things.yaml a.b.c true
+yq write things.yaml 'a.*.c' true
+yq write things.yaml 'a.**' true
+yq write things.yaml a.b.c --tag '!!str' true
+yq write things.yaml a.b.c --tag '!!float' 3
 yq write --inplace -- things.yaml a.b.c --cat
 yq w -i things.yaml a.b.c cat
 yq w --script update_script.yaml things.yaml
 yq w -i -s update_script.yaml things.yaml
-yq w --doc 2 things.yaml a.b.d[+] foo
-yq w -d2 things.yaml a.b.d[+] foo
+yq w --doc 2 things.yaml 'a.b.d[+]' foo
+yq w -d2 things.yaml 'a.b.d[+]' foo
       `,
 		Long: `Updates the yaml file w.r.t the given path and value.
 Outputs to STDOUT unless the inplace flag is used, in which case the file is updated instead.
@@ -127,23 +136,28 @@ Outputs to STDOUT unless the inplace flag is used, in which case the file is upd
 Append value to array adds the value to the end of array.
 
 Update Scripts:
-Note that you can give an update script to perform more sophisticated updated. Update script
-format is a yaml map where the key is the path and the value is..well the value. e.g.:
+Note that you can give an update script to perform more sophisticated update. Update script
+format is list of update commands (update or delete) like so:
 ---
-a.b.c: true,
-a.b.e:
-  - name: bob
+- command: update 
+  path: b.c
+  value:
+    #great 
+    things: frog # wow!
+- command: delete
+  path: b.d
 `,
 		RunE: writeProperty,
 	}
 	cmdWrite.PersistentFlags().BoolVarP(&writeInplace, "inplace", "i", false, "update the yaml file inplace")
 	cmdWrite.PersistentFlags().StringVarP(&writeScript, "script", "s", "", "yaml script for updating yaml")
+	cmdWrite.PersistentFlags().StringVarP(&customTag, "tag", "t", "", "set yaml tag (e.g. !!int)")
 	cmdWrite.PersistentFlags().StringVarP(&docIndex, "doc", "d", "0", "process document index number (0 based, * for all documents)")
 	return cmdWrite
 }
 
 func createPrefixCmd() *cobra.Command {
-	var cmdWrite = &cobra.Command{
+	var cmdPrefix = &cobra.Command{
 		Use:     "prefix [yaml_file] [path]",
 		Aliases: []string{"p"},
 		Short:   "yq p [--inplace/-i] [--doc/-d index] sample.yaml a.b.c",
@@ -160,9 +174,9 @@ Outputs to STDOUT unless the inplace flag is used, in which case the file is upd
 `,
 		RunE: prefixProperty,
 	}
-	cmdWrite.PersistentFlags().BoolVarP(&writeInplace, "inplace", "i", false, "update the yaml file inplace")
-	cmdWrite.PersistentFlags().StringVarP(&docIndex, "doc", "d", "0", "process document index number (0 based, * for all documents)")
-	return cmdWrite
+	cmdPrefix.PersistentFlags().BoolVarP(&writeInplace, "inplace", "i", false, "update the yaml file inplace")
+	cmdPrefix.PersistentFlags().StringVarP(&docIndex, "doc", "d", "0", "process document index number (0 based, * for all documents)")
+	return cmdPrefix
 }
 
 func createDeleteCmd() *cobra.Command {
@@ -172,6 +186,8 @@ func createDeleteCmd() *cobra.Command {
 		Short:   "yq d [--inplace/-i] [--doc/-d index] sample.yaml a.b.c",
 		Example: `
 yq delete things.yaml a.b.c
+yq delete things.yaml a.*.c
+yq delete things.yaml a.**
 yq delete --inplace things.yaml a.b.c
 yq delete --inplace -- things.yaml --key-starting-with-dash
 yq d -i things.yaml a.b.c
@@ -195,6 +211,7 @@ func createNewCmd() *cobra.Command {
 		Example: `
 yq new a.b.c cat
 yq n a.b.c cat
+yq n a.b[+] --tag '!!str' true
 yq n -- --key-starting-with-dash cat
 yq n --script create_script.yaml
       `,
@@ -206,7 +223,8 @@ Note that you can give a create script to perform more sophisticated yaml. This
 `,
 		RunE: newProperty,
 	}
-	cmdNew.PersistentFlags().StringVarP(&writeScript, "script", "s", "", "yaml script for updating yaml")
+	cmdNew.PersistentFlags().StringVarP(&writeScript, "script", "s", "", "yaml script for creating yaml")
+	cmdNew.PersistentFlags().StringVarP(&customTag, "tag", "t", "", "set yaml tag (e.g. !!int)")
 	return cmdNew
 }
 
@@ -222,19 +240,19 @@ yq m -i things.yaml other.yaml
 yq m --overwrite things.yaml other.yaml
 yq m -i -x things.yaml other.yaml
 yq m -i -a things.yaml other.yaml
+yq m -i --autocreate=false things.yaml other.yaml
       `,
 		Long: `Updates the yaml file by adding/updating the path(s) and value(s) from additional yaml file(s).
 Outputs to STDOUT unless the inplace flag is used, in which case the file is updated instead.
 
 If overwrite flag is set then existing values will be overwritten using the values from each additional yaml file.
 If append flag is set then existing arrays will be merged with the arrays from each additional yaml file.
-
-Note that if you set both flags only overwrite will take effect.
 `,
 		RunE: mergeProperties,
 	}
 	cmdMerge.PersistentFlags().BoolVarP(&writeInplace, "inplace", "i", false, "update the yaml file inplace")
 	cmdMerge.PersistentFlags().BoolVarP(&overwriteFlag, "overwrite", "x", false, "update the yaml file by overwriting existing values")
+	cmdMerge.PersistentFlags().BoolVarP(&autoCreateFlag, "autocreate", "c", true, "automatically create any missing entries")
 	cmdMerge.PersistentFlags().BoolVarP(&appendFlag, "append", "a", false, "update the yaml file by appending array values")
 	cmdMerge.PersistentFlags().BoolVarP(&allowEmptyFlag, "allow-empty", "e", false, "allow empty yaml files")
 	cmdMerge.PersistentFlags().StringVarP(&docIndex, "doc", "d", "0", "process document index number (0 based, * for all documents)")
@@ -254,96 +272,117 @@ func readProperty(cmd *cobra.Command, args []string) error {
 	if errorParsingDocIndex != nil {
 		return errorParsingDocIndex
 	}
-	var mappedDocs []interface{}
-	var dataBucket interface{}
-	var currentIndex = 0
-	var errorReadingStream = readStream(args[0], func(decoder *yaml.Decoder) error {
-		for {
-			errorReading := decoder.Decode(&dataBucket)
-			if errorReading == io.EOF {
-				log.Debugf("done %v / %v", currentIndex, docIndexInt)
-				if !updateAll && currentIndex <= docIndexInt {
-					return fmt.Errorf("asked to process document index %v but there are only %v document(s)", docIndex, currentIndex)
-				}
-				return nil
-			}
-			log.Debugf("processing %v - requested index %v", currentIndex, docIndexInt)
-			if updateAll || currentIndex == docIndexInt {
-				log.Debugf("reading %v in index %v", path, currentIndex)
-				mappedDoc, errorParsing := readPath(dataBucket, path)
-				log.Debugf("%v", mappedDoc)
-				if errorParsing != nil {
-					return errors.Wrapf(errorParsing, "Error reading path in document index %v", currentIndex)
-				}
-				mappedDocs = append(mappedDocs, mappedDoc)
-			}
-			currentIndex = currentIndex + 1
-		}
-	})
+
+	matchingNodes, errorReadingStream := readYamlFile(args[0], path, updateAll, docIndexInt)
 
 	if errorReadingStream != nil {
 		return errorReadingStream
 	}
 
-	if !updateAll {
-		dataBucket = mappedDocs[0]
-	} else {
-		dataBucket = mappedDocs
-	}
+	return printResults(matchingNodes, cmd)
+}
 
-	dataStr, err := toString(dataBucket)
-	if err != nil {
-		return err
+func readYamlFile(filename string, path string, updateAll bool, docIndexInt int) ([]*yqlib.NodeContext, error) {
+	var matchingNodes []*yqlib.NodeContext
+
+	var currentIndex = 0
+	var errorReadingStream = readStream(filename, func(decoder *yaml.Decoder) error {
+		for {
+			var dataBucket yaml.Node
+			errorReading := decoder.Decode(&dataBucket)
+
+			if errorReading == io.EOF {
+				return handleEOF(updateAll, docIndexInt, currentIndex)
+			}
+			var errorParsing error
+			matchingNodes, errorParsing = appendDocument(matchingNodes, dataBucket, path, updateAll, docIndexInt, currentIndex)
+			if errorParsing != nil {
+				return errorParsing
+			}
+			currentIndex = currentIndex + 1
+		}
+	})
+	return matchingNodes, errorReadingStream
+}
+
+func handleEOF(updateAll bool, docIndexInt int, currentIndex int) error {
+	log.Debugf("done %v / %v", currentIndex, docIndexInt)
+	if !updateAll && currentIndex <= docIndexInt {
+		return fmt.Errorf("Could not process document index %v as there are only %v document(s)", docIndex, currentIndex)
 	}
-	cmd.Println(dataStr)
 	return nil
 }
 
-func readPath(dataBucket interface{}, path string) (interface{}, error) {
-	if path == "" {
-		log.Debug("no path")
-		return dataBucket, nil
+func appendDocument(originalMatchingNodes []*yqlib.NodeContext, dataBucket yaml.Node, path string, updateAll bool, docIndexInt int, currentIndex int) ([]*yqlib.NodeContext, error) {
+	log.Debugf("processing document %v - requested index %v", currentIndex, docIndexInt)
+	yqlib.DebugNode(&dataBucket)
+	if !updateAll && currentIndex != docIndexInt {
+		return originalMatchingNodes, nil
 	}
-	var paths = parsePath(path)
-	return recurse(dataBucket, paths[0], paths[1:])
+	log.Debugf("reading %v in document %v", path, currentIndex)
+	matchingNodes, errorParsing := lib.Get(&dataBucket, path)
+	if errorParsing != nil {
+		return nil, errors.Wrapf(errorParsing, "Error reading path in document index %v", currentIndex)
+	}
+	return append(originalMatchingNodes, matchingNodes...), nil
 }
 
-func newProperty(cmd *cobra.Command, args []string) error {
-	updatedData, err := newYaml(args)
-	if err != nil {
+func printValue(node *yaml.Node, cmd *cobra.Command) error {
+	if node.Kind == yaml.ScalarNode {
+		cmd.Print(node.Value)
+		return nil
+	}
+
+	bufferedWriter := bufio.NewWriter(cmd.OutOrStdout())
+	defer safelyFlush(bufferedWriter)
+
+	var encoder yqlib.Encoder
+	if outputToJSON {
+		encoder = yqlib.NewJsonEncoder(bufferedWriter)
+	} else {
+		encoder = yqlib.NewYamlEncoder(bufferedWriter)
+	}
+	if err := encoder.Encode(node); err != nil {
 		return err
 	}
-	dataStr, err := toString(updatedData)
-	if err != nil {
-		return err
-	}
-	cmd.Println(dataStr)
 	return nil
 }
 
-func newYaml(args []string) (interface{}, error) {
-	var writeCommands, writeCommandsError = readWriteCommands(args, 2, "Must provide <path_to_update> <value>")
-	if writeCommandsError != nil {
-		return nil, writeCommandsError
+func printResults(matchingNodes []*yqlib.NodeContext, cmd *cobra.Command) error {
+	if len(matchingNodes) == 0 {
+		log.Debug("no matching results, nothing to print")
+		return nil
 	}
 
-	var dataBucket interface{}
-	var isArray = strings.HasPrefix(writeCommands[0].Key.(string), "[")
-	if isArray {
-		dataBucket = make([]interface{}, 0)
-	} else {
-		dataBucket = make(yaml.MapSlice, 0)
+	for index, mappedDoc := range matchingNodes {
+		switch printMode {
+		case "p":
+			cmd.Print(lib.PathStackToString(mappedDoc.PathStack))
+			if index < len(matchingNodes)-1 {
+				cmd.Print("\n")
+			}
+		case "pv", "vp":
+			// put it into a node and print that.
+			var parentNode = yaml.Node{Kind: yaml.MappingNode}
+			parentNode.Content = make([]*yaml.Node, 2)
+			parentNode.Content[0] = &yaml.Node{Kind: yaml.ScalarNode, Value: lib.PathStackToString(mappedDoc.PathStack)}
+			parentNode.Content[1] = mappedDoc.Node
+			if err := printValue(&parentNode, cmd); err != nil {
+				return err
+			}
+		default:
+			if err := printValue(mappedDoc.Node, cmd); err != nil {
+				return err
+			}
+			// Printing our Scalars does not print a new line at the end
+			// we only want to do that if there are more values (so users can easily script extraction of values in the yaml)
+			if index < len(matchingNodes)-1 && mappedDoc.Node.Kind == yaml.ScalarNode {
+				cmd.Print("\n")
+			}
+		}
 	}
 
-	for _, entry := range writeCommands {
-		path := entry.Key.(string)
-		value := entry.Value
-		log.Debugf("setting %v to %v", path, value)
-		var paths = parsePath(path)
-		dataBucket = updatedChildValue(dataBucket, paths, value)
-	}
-
-	return dataBucket, nil
+	return nil
 }
 
 func parseDocumentIndex() (bool, int, error) {
@@ -357,11 +396,11 @@ func parseDocumentIndex() (bool, int, error) {
 	return false, int(docIndexInt64), nil
 }
 
-type updateDataFn func(dataBucket interface{}, currentIndex int) (interface{}, error)
+type updateDataFn func(dataBucket *yaml.Node, currentIndex int) error
 
-func mapYamlDecoder(updateData updateDataFn, encoder *yaml.Encoder) yamlDecoderFn {
+func mapYamlDecoder(updateData updateDataFn, encoder yqlib.Encoder) yamlDecoderFn {
 	return func(decoder *yaml.Decoder) error {
-		var dataBucket interface{}
+		var dataBucket yaml.Node
 		var errorReading error
 		var errorWriting error
 		var errorUpdating error
@@ -384,12 +423,12 @@ func mapYamlDecoder(updateData updateDataFn, encoder *yaml.Encoder) yamlDecoderF
 			} else if errorReading != nil {
 				return errors.Wrapf(errorReading, "Error reading document at index %v, %v", currentIndex, errorReading)
 			}
-			dataBucket, errorUpdating = updateData(dataBucket, currentIndex)
+			errorUpdating = updateData(&dataBucket, currentIndex)
 			if errorUpdating != nil {
 				return errors.Wrapf(errorUpdating, "Error updating document at index %v", currentIndex)
 			}
 
-			errorWriting = encoder.Encode(dataBucket)
+			errorWriting = encoder.Encode(&dataBucket)
 
 			if errorWriting != nil {
 				return errors.Wrapf(errorWriting, "Error writing document at index %v, %v", currentIndex, errorWriting)
@@ -400,62 +439,125 @@ func mapYamlDecoder(updateData updateDataFn, encoder *yaml.Encoder) yamlDecoderF
 }
 
 func writeProperty(cmd *cobra.Command, args []string) error {
-	var writeCommands, writeCommandsError = readWriteCommands(args, 3, "Must provide <filename> <path_to_update> <value>")
-	if writeCommandsError != nil {
-		return writeCommandsError
+	var updateCommands, updateCommandsError = readUpdateCommands(args, 3, "Must provide <filename> <path_to_update> <value>")
+	if updateCommandsError != nil {
+		return updateCommandsError
 	}
+	return updateDoc(args[0], updateCommands, cmd.OutOrStdout())
+}
+
+func mergeProperties(cmd *cobra.Command, args []string) error {
+	if len(args) < 2 {
+		return errors.New("Must provide at least 2 yaml files")
+	}
+	// first generate update commands from the file
+	var filesToMerge = args[1:]
+	var updateCommands []yqlib.UpdateCommand = make([]yqlib.UpdateCommand, 0)
+
+	for _, fileToMerge := range filesToMerge {
+		matchingNodes, errorProcessingFile := readYamlFile(fileToMerge, "**", false, 0)
+		if errorProcessingFile != nil && (!allowEmptyFlag || !strings.HasPrefix(errorProcessingFile.Error(), "Could not process document index")) {
+			return errorProcessingFile
+		}
+		for _, matchingNode := range matchingNodes {
+			mergePath := lib.MergePathStackToString(matchingNode.PathStack, appendFlag)
+			updateCommands = append(updateCommands, yqlib.UpdateCommand{Command: "update", Path: mergePath, Value: matchingNode.Node, Overwrite: overwriteFlag})
+		}
+	}
+
+	return updateDoc(args[0], updateCommands, cmd.OutOrStdout())
+}
+
+func newProperty(cmd *cobra.Command, args []string) error {
+	var updateCommands, updateCommandsError = readUpdateCommands(args, 2, "Must provide <path_to_update> <value>")
+	if updateCommandsError != nil {
+		return updateCommandsError
+	}
+	newNode := lib.New(updateCommands[0].Path)
+
+	for _, updateCommand := range updateCommands {
+
+		errorUpdating := lib.Update(&newNode, updateCommand, true)
+
+		if errorUpdating != nil {
+			return errorUpdating
+		}
+	}
+
+	var encoder = yaml.NewEncoder(cmd.OutOrStdout())
+	encoder.SetIndent(2)
+	errorEncoding := encoder.Encode(&newNode)
+	encoder.Close()
+	return errorEncoding
+}
+
+func prefixProperty(cmd *cobra.Command, args []string) error {
+
+	if len(args) < 2 {
+		return errors.New("Must provide <filename> <prefixed_path>")
+	}
+	updateCommand := yqlib.UpdateCommand{Command: "update", Path: args[1]}
+	log.Debugf("args %v", args)
+
 	var updateAll, docIndexInt, errorParsingDocIndex = parseDocumentIndex()
 	if errorParsingDocIndex != nil {
 		return errorParsingDocIndex
 	}
 
-	var updateData = func(dataBucket interface{}, currentIndex int) (interface{}, error) {
-		if updateAll || currentIndex == docIndexInt {
-			log.Debugf("Updating doc %v", currentIndex)
-			for _, entry := range writeCommands {
-				path := entry.Key.(string)
-				value := entry.Value
-				log.Debugf("setting %v to %v", path, value)
-				var paths = parsePath(path)
-				dataBucket = updatedChildValue(dataBucket, paths, value)
-			}
-		}
-		return dataBucket, nil
+	var updateData = func(dataBucket *yaml.Node, currentIndex int) error {
+		return prefixDocument(updateAll, docIndexInt, currentIndex, dataBucket, updateCommand)
 	}
 	return readAndUpdate(cmd.OutOrStdout(), args[0], updateData)
 }
 
-func prefixProperty(cmd *cobra.Command, args []string) error {
-	if len(args) != 2 {
-		return errors.New("Must provide <filename> <prefixed_path>")
+func prefixDocument(updateAll bool, docIndexInt int, currentIndex int, dataBucket *yaml.Node, updateCommand yqlib.UpdateCommand) error {
+	if updateAll || currentIndex == docIndexInt {
+		log.Debugf("Prefixing document %v", currentIndex)
+		yqlib.DebugNode(dataBucket)
+		updateCommand.Value = dataBucket.Content[0]
+		dataBucket.Content = make([]*yaml.Node, 1)
+
+		newNode := lib.New(updateCommand.Path)
+		dataBucket.Content[0] = &newNode
+
+		errorUpdating := lib.Update(dataBucket, updateCommand, true)
+		if errorUpdating != nil {
+			return errorUpdating
+		}
 	}
+	return nil
+}
+
+func deleteProperty(cmd *cobra.Command, args []string) error {
+	if len(args) < 2 {
+		return errors.New("Must provide <filename> <path_to_delete>")
+	}
+	var updateCommands []yqlib.UpdateCommand = make([]yqlib.UpdateCommand, 1)
+	updateCommands[0] = yqlib.UpdateCommand{Command: "delete", Path: args[1]}
+
+	return updateDoc(args[0], updateCommands, cmd.OutOrStdout())
+}
+
+func updateDoc(inputFile string, updateCommands []yqlib.UpdateCommand, writer io.Writer) error {
 	var updateAll, docIndexInt, errorParsingDocIndex = parseDocumentIndex()
 	if errorParsingDocIndex != nil {
 		return errorParsingDocIndex
 	}
 
-	var paths = parsePath(args[1])
-
-	// Inverse order
-	for i := len(paths)/2 - 1; i >= 0; i-- {
-		opp := len(paths) - 1 - i
-		paths[i], paths[opp] = paths[opp], paths[i]
-	}
-
-	var updateData = func(dataBucket interface{}, currentIndex int) (interface{}, error) {
-
+	var updateData = func(dataBucket *yaml.Node, currentIndex int) error {
 		if updateAll || currentIndex == docIndexInt {
-			log.Debugf("Prefixing %v to doc %v", paths, currentIndex)
-			var mapDataBucket = dataBucket
-			for _, key := range paths {
-				singlePath := []string{key}
-				mapDataBucket = updatedChildValue(nil, singlePath, mapDataBucket)
+			log.Debugf("Updating doc %v", currentIndex)
+			for _, updateCommand := range updateCommands {
+				log.Debugf("Processing update to Path %v", updateCommand.Path)
+				errorUpdating := lib.Update(dataBucket, updateCommand, autoCreateFlag)
+				if errorUpdating != nil {
+					return errorUpdating
+				}
 			}
-			return mapDataBucket, nil
 		}
-		return dataBucket, nil
+		return nil
 	}
-	return readAndUpdate(cmd.OutOrStdout(), args[0], updateData)
+	return readAndUpdate(writer, inputFile, updateData)
 }
 
 func readAndUpdate(stdOut io.Writer, inputFile string, updateData updateDataFn) error {
@@ -481,152 +583,64 @@ func readAndUpdate(stdOut io.Writer, inputFile string, updateData updateDataFn)
 			safelyRenameFile(tempFile.Name(), inputFile)
 		}()
 	} else {
-		var writer = bufio.NewWriter(stdOut)
-		destination = writer
+		destination = stdOut
 		destinationName = "Stdout"
-		defer safelyFlush(writer)
 	}
-	var encoder = yaml.NewEncoder(destination)
+
 	log.Debugf("Writing to %v from %v", destinationName, inputFile)
+
+	bufferedWriter := bufio.NewWriter(destination)
+	defer safelyFlush(bufferedWriter)
+
+	var encoder yqlib.Encoder
+	if outputToJSON {
+		encoder = yqlib.NewJsonEncoder(bufferedWriter)
+	} else {
+		encoder = yqlib.NewYamlEncoder(bufferedWriter)
+	}
 	return readStream(inputFile, mapYamlDecoder(updateData, encoder))
 }
 
-func deleteProperty(cmd *cobra.Command, args []string) error {
-	if len(args) < 2 {
-		return errors.New("Must provide <filename> <path_to_delete>")
-	}
-	var deletePath = args[1]
-	var paths = parsePath(deletePath)
-	var updateAll, docIndexInt, errorParsingDocIndex = parseDocumentIndex()
-	if errorParsingDocIndex != nil {
-		return errorParsingDocIndex
-	}
-
-	var updateData = func(dataBucket interface{}, currentIndex int) (interface{}, error) {
-		if updateAll || currentIndex == docIndexInt {
-			log.Debugf("Deleting path in doc %v", currentIndex)
-			return deleteChildValue(dataBucket, paths)
-		}
-		return dataBucket, nil
-	}
-
-	return readAndUpdate(cmd.OutOrStdout(), args[0], updateData)
+type updateCommandParsed struct {
+	Command string
+	Path    string
+	Value   yaml.Node
 }
 
-func mergeProperties(cmd *cobra.Command, args []string) error {
-	if len(args) < 2 {
-		return errors.New("Must provide at least 2 yaml files")
-	}
-	var input = args[0]
-	var filesToMerge = args[1:]
-	var updateAll, docIndexInt, errorParsingDocIndex = parseDocumentIndex()
-	if errorParsingDocIndex != nil {
-		return errorParsingDocIndex
-	}
-
-	var updateData = func(dataBucket interface{}, currentIndex int) (interface{}, error) {
-		if updateAll || currentIndex == docIndexInt {
-			log.Debugf("Merging doc %v", currentIndex)
-			var mergedData map[interface{}]interface{}
-			// merge only works for maps, so put everything in a temporary
-			// map
-			var mapDataBucket = make(map[interface{}]interface{})
-			mapDataBucket["root"] = dataBucket
-			if err := merge(&mergedData, mapDataBucket, overwriteFlag, appendFlag); err != nil {
-				return nil, err
-			}
-			for _, f := range filesToMerge {
-				var fileToMerge interface{}
-				if err := readData(f, 0, &fileToMerge); err != nil {
-					if allowEmptyFlag && err == io.EOF {
-						continue
-					}
-					return nil, err
-				}
-				mapDataBucket["root"] = fileToMerge
-				if err := merge(&mergedData, mapDataBucket, overwriteFlag, appendFlag); err != nil {
-					return nil, err
-				}
-			}
-			return mergedData["root"], nil
-		}
-		return dataBucket, nil
-	}
-	yaml.DefaultMapType = reflect.TypeOf(map[interface{}]interface{}{})
-	defer func() { yaml.DefaultMapType = reflect.TypeOf(yaml.MapSlice{}) }()
-	return readAndUpdate(cmd.OutOrStdout(), input, updateData)
-}
-
-func readWriteCommands(args []string, expectedArgs int, badArgsMessage string) (yaml.MapSlice, error) {
-	var writeCommands yaml.MapSlice
+func readUpdateCommands(args []string, expectedArgs int, badArgsMessage string) ([]yqlib.UpdateCommand, error) {
+	var updateCommands []yqlib.UpdateCommand = make([]yqlib.UpdateCommand, 0)
 	if writeScript != "" {
-		if err := readData(writeScript, 0, &writeCommands); err != nil {
+		var parsedCommands = make([]updateCommandParsed, 0)
+
+		err := readData(writeScript, 0, &parsedCommands)
+
+		if err != nil && err != io.EOF {
 			return nil, err
 		}
+
+		log.Debugf("Read write commands file '%v'", parsedCommands)
+		for index := range parsedCommands {
+			parsedCommand := parsedCommands[index]
+			updateCommand := yqlib.UpdateCommand{Command: parsedCommand.Command, Path: parsedCommand.Path, Value: &parsedCommand.Value, Overwrite: true}
+			updateCommands = append(updateCommands, updateCommand)
+		}
+
+		log.Debugf("Read write commands file '%v'", updateCommands)
 	} else if len(args) < expectedArgs {
 		return nil, errors.New(badArgsMessage)
 	} else {
-		writeCommands = make(yaml.MapSlice, 1)
-		writeCommands[0] = yaml.MapItem{Key: args[expectedArgs-2], Value: parseValue(args[expectedArgs-1])}
+		updateCommands = make([]yqlib.UpdateCommand, 1)
+		log.Debug("args %v", args)
+		log.Debug("path %v", args[expectedArgs-2])
+		log.Debug("Value %v", args[expectedArgs-1])
+		updateCommands[0] = yqlib.UpdateCommand{Command: "update", Path: args[expectedArgs-2], Value: valueParser.Parse(args[expectedArgs-1], customTag), Overwrite: true}
 	}
-	return writeCommands, nil
-}
-
-func parseValue(argument string) interface{} {
-	var value, err interface{}
-	var inQuotes = len(argument) > 0 && argument[0] == '"'
-	if !inQuotes {
-		value, err = strconv.ParseFloat(argument, 64)
-		if err == nil {
-			return value
-		}
-		value, err = strconv.ParseBool(argument)
-		if err == nil {
-			return value
-		}
-		if argument == "[]" {
-			return make([]interface{}, 0)
-		}
-		return argument
-	}
-	return argument[1 : len(argument)-1]
-}
-
-func toString(context interface{}) (string, error) {
-	if outputToJSON {
-		return jsonToString(context)
-	}
-	return yamlToString(context)
-}
-
-func yamlToString(context interface{}) (string, error) {
-	switch context := context.(type) {
-	case string:
-		return context, nil
-	default:
-		return marshalContext(context)
-	}
-}
-
-func marshalContext(context interface{}) (string, error) {
-	out, err := yaml.Marshal(context)
-
-	if err != nil {
-		return "", errors.Wrap(err, "error printing yaml")
-	}
-
-	outStr := string(out)
-	// trim the trailing new line as it's easier for a script to add
-	// it in if required than to remove it
-	if trimOutput {
-		return strings.Trim(outStr, "\n "), nil
-	}
-	return outStr, nil
+	return updateCommands, nil
 }
 
 func safelyRenameFile(from string, to string) {
 	if renameError := os.Rename(from, to); renameError != nil {
-		log.Debugf("Error renaming from %v to %v, attemting to copy contents", from, to)
+		log.Debugf("Error renaming from %v to %v, attempting to copy contents", from, to)
 		log.Debug(renameError.Error())
 		// can't do this rename when running in docker to a file targeted in a mounted volume,
 		// so gracefully degrade to copying the entire contents.

yq_test.go

@@ -1,75 +1,60 @@
 package main
 
-import (
-	"fmt"
-	"runtime"
-	"testing"
-)
+// import (
+// 	"fmt"
+// 	"runtime"
+// 	"testing"
 
-var parseValueTests = []struct {
-	argument        string
-	expectedResult  interface{}
-	testDescription string
-}{
-	{"true", true, "boolean"},
-	{"\"true\"", "true", "boolean as string"},
-	{"3.4", 3.4, "number"},
-	{"\"3.4\"", "3.4", "number as string"},
-	{"", "", "empty string"},
-}
+// 	"github.com/mikefarah/yq/v2/pkg/marshal"
+// 	"github.com/mikefarah/yq/v2/test"
+// )
 
-func TestParseValue(t *testing.T) {
-	for _, tt := range parseValueTests {
-		assertResultWithContext(t, tt.expectedResult, parseValue(tt.argument), tt.testDescription)
-	}
-}
+// func TestMultilineString(t *testing.T) {
+// 	testString := `
+// 	abcd
+// 	efg`
+// 	formattedResult, _ := marshal.NewYamlConverter().YamlToString(testString, false)
+// 	test.AssertResult(t, testString, formattedResult)
+// }
 
-func TestMultilineString(t *testing.T) {
-	testString := `
-	abcd
-	efg`
-	formattedResult, _ := yamlToString(testString)
-	assertResult(t, testString, formattedResult)
-}
+// func TestNewYaml(t *testing.T) {
+// 	result, _ := newYaml([]string{"b.c", "3"})
+// 	formattedResult := fmt.Sprintf("%v", result)
+// 	test.AssertResult(t,
+// 		"[{b [{c 3}]}]",
+// 		formattedResult)
+// }
 
-func TestNewYaml(t *testing.T) {
-	result, _ := newYaml([]string{"b.c", "3"})
-	formattedResult := fmt.Sprintf("%v", result)
-	assertResult(t,
-		"[{b [{c 3}]}]",
-		formattedResult)
-}
+// func TestNewYamlArray(t *testing.T) {
+// 	result, _ := newYaml([]string{"[0].cat", "meow"})
+// 	formattedResult := fmt.Sprintf("%v", result)
+// 	test.AssertResult(t,
+// 		"[[{cat meow}]]",
+// 		formattedResult)
+// }
 
-func TestNewYamlArray(t *testing.T) {
-	result, _ := newYaml([]string{"[0].cat", "meow"})
-	formattedResult := fmt.Sprintf("%v", result)
-	assertResult(t,
-		"[[{cat meow}]]",
-		formattedResult)
-}
+// func TestNewYaml_WithScript(t *testing.T) {
+// 	writeScript = "examples/instruction_sample.yaml"
+// 	expectedResult := `b:
+//   c: cat
+//   e:
+//   - name: Mike Farah`
+// 	result, _ := newYaml([]string{""})
+// 	actualResult, _ := marshal.NewYamlConverter().YamlToString(result, true)
+// 	test.AssertResult(t, expectedResult, actualResult)
+// }
 
-func TestNewYaml_WithScript(t *testing.T) {
-	writeScript = "examples/instruction_sample.yaml"
-	expectedResult := `b:
-  c: cat
-  e:
-  - name: Mike Farah`
-	result, _ := newYaml([]string{""})
-	actualResult, _ := yamlToString(result)
-	assertResult(t, expectedResult, actualResult)
-}
-
-func TestNewYaml_WithUnknownScript(t *testing.T) {
-	writeScript = "fake-unknown"
-	_, err := newYaml([]string{""})
-	if err == nil {
-		t.Error("Expected error due to unknown file")
-	}
-	var expectedOutput string
-	if runtime.GOOS == "windows" {
-		expectedOutput = `open fake-unknown: The system cannot find the file specified.`
-	} else {
-		expectedOutput = `open fake-unknown: no such file or directory`
-	}
-	assertResult(t, expectedOutput, err.Error())
-}
+// func TestNewYaml_WithUnknownScript(t *testing.T) {
+// 	writeScript = "fake-unknown"
+// 	_, err := newYaml([]string{""})
+// 	if err == nil {
+// 		t.Error("Expected error due to unknown file")
+// 	}
+// 	var expectedOutput string
+// 	if runtime.GOOS == "windows" {
+// 		expectedOutput = `open fake-unknown: The system cannot find the file specified.`
+// 	} else {
+// 		expectedOutput = `open fake-unknown: no such file or directory`
+// 	}
+// 	test.AssertResult(t, expectedOutput, err.Error())
+// }