Remove trim flag as its not properly supported by the cli package

README.md

@@ -1,9 +1,11 @@
 # yaml
 yaml command line tool written in go
 
-Allows you to read (and soon update) yaml files given a yaml path.
+Allows you to read (and soon update) yaml files given a yaml path. All in a lovely dependency free binary!
 
-## Install
+[Download latest release](https://github.com/mikefarah/yaml/releases/latest)
+
+or alternatively install using go get:
 ```
 go get github.com/mikefarah/yaml
 ```
@@ -25,6 +27,18 @@ yaml sample.yaml b.c
 ```
 will output the value of '2'.
 
+### Handling '.' in the yaml key
+Given a sample.yaml file of:
+```yaml
+b.x:
+  c: 2
+```
+then
+```bash
+yaml sample.yaml \"b.x\".c
+```
+will output the value of '2'.
+
 ### Arrays
 You can give an index to access a specific element:
 e.g.: given a sample file of
@@ -38,10 +52,22 @@ b:
 ```
 then
 ```
-yaml sample.yaml b.e.1.name
+yaml sample.yaml b.e[1].name
 ```
 will output 'sam'
 
-## TODO
+### Updating yaml
-* Updating yaml files
+Given a sample.yaml file of:
-* Handling '.' in path names
+```yaml
+b:
+  c: 2
+```
+then
+```bash
+yaml w sample.yaml b.c 'cat'
+```
+will output:
+```yaml
+b:
+  c: cat
+```

data_navigator.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	// "fmt"
+	"log"
+	"strconv"
+)
+
+func write(context map[interface{}]interface{}, head string, tail []string, value interface{}) {
+	// e.g. if updating a.b.c, we need to get the 'b' map...
+	toUpdate := readMap(context, head, tail[0:len(tail)-1]).(map[interface{}]interface{})
+	//  and then set the 'c' key.
+	key := (tail[len(tail)-1])
+	toUpdate[key] = value
+}
+
+func readMap(context map[interface{}]interface{}, head string, tail []string) interface{} {
+	value := context[head]
+	if len(tail) > 0 {
+		return recurse(value, tail[0], tail[1:len(tail)])
+	}
+	return value
+}
+
+func recurse(value interface{}, head string, tail []string) interface{} {
+	switch value.(type) {
+	case []interface{}:
+		index, err := strconv.ParseInt(head, 10, 64)
+		if err != nil {
+			log.Fatalf("Error accessing array: %v", err)
+		}
+		return readArray(value.([]interface{}), index, tail)
+	case nil:
+		return nil
+	default:
+		return readMap(value.(map[interface{}]interface{}), head, tail)
+	}
+}
+
+func readArray(array []interface{}, head int64, tail []string) interface{} {
+	if head > int64(len(array)) {
+		return nil
+	}
+
+	value := array[head]
+	if len(tail) > 0 {
+		return recurse(value, tail[0], tail[1:len(tail)])
+	}
+	return value
+}

data_navigator_test.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"fmt"
+	"gopkg.in/yaml.v2"
+	"os"
+	"testing"
+)
+
+var rawData = `
+a: Easy!
+b:
+  c: 2
+  d: [3, 4]
+`
+
+var parsedData map[interface{}]interface{}
+
+func TestMain(m *testing.M) {
+	err := yaml.Unmarshal([]byte(rawData), &parsedData)
+	if err != nil {
+		fmt.Println("Error parsing yaml: %v", err)
+		os.Exit(1)
+	}
+
+	os.Exit(m.Run())
+}
+
+func TestReadMap_simple(t *testing.T) {
+	assertResult(t, 2, readMap(parsedData, "b", []string{"c"}))
+}
+
+func TestReadMap_key_doesnt_exist(t *testing.T) {
+	assertResult(t, nil, readMap(parsedData, "b.x.f", []string{"c"}))
+}
+
+func TestReadMap_with_array(t *testing.T) {
+	assertResult(t, 4, readMap(parsedData, "b", []string{"d", "1"}))
+}
+
+func TestReadMap_with_array_out_of_bounds(t *testing.T) {
+	assertResult(t, nil, readMap(parsedData, "b", []string{"d", "3"}))
+}
+
+func TestWrite_simple(t *testing.T) {
+
+	write(parsedData, "b", []string{"c"}, "4")
+
+	b := parsedData["b"].(map[interface{}]interface{})
+	assertResult(t, "4", b["c"].(string))
+}
+
+func assertResult(t *testing.T, expectedValue interface{}, actualValue interface{}) {
+	if expectedValue != actualValue {
+		t.Error("Expected <", expectedValue, "> but got <", actualValue, ">")
+	}
+}
+
+func assertResultWithContext(t *testing.T, expectedValue interface{}, actualValue interface{}, context interface{}) {
+	if expectedValue != actualValue {
+		t.Error(context)
+		t.Error(": expected <", expectedValue, "> but got <", actualValue, ">")
+	}
+}

path_parser.go

@@ -0,0 +1,55 @@
+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:len(path)], []uint8{']'}, true)
+	case '"':
+		// e.g "a.b".blah.cat -> we need to return "a.b" and "blah.cat"
+		return search(path[1:len(path)], []uint8{'"'}, true)
+	default:
+		// e.g "a.blah.cat" -> return "a" and "blah.cat"
+		return search(path[0:len(path)], []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:len(path)]
+		}
+	}
+	return path, ""
+}
+
+func contains(matchingChars []uint8, candidate uint8) bool {
+	for _, a := range matchingChars {
+		if a == candidate {
+			return true
+		}
+	}
+	return false
+}

path_parser_test.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"testing"
+)
+
+var parsePathsTests = []struct {
+	path          string
+	expectedPaths []string
+}{
+	{"a.b", []string{"a", "b"}},
+	{"a.b[0]", []string{"a", "b", "0"}},
+}
+
+func testParsePath(t *testing.T) {
+	for _, tt := range parsePathsTests {
+		assertResultWithContext(t, tt.expectedPaths, parsePath(tt.path), tt)
+	}
+}
+
+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)
+	}
+}

precheckin.sh

@@ -5,9 +5,13 @@ golint
 go test
 
 # acceptance test
-X=$(go run yaml.go  sample.yaml b.c)
+go build
+X=$(./yaml sample.yaml b.c)
 
 if [ $X != 2 ]
   then
 	echo "Failed acceptance test: expected 2 but was $X"
+  exit 1
 fi
+
+go install

yaml.go

@@ -19,22 +19,77 @@ func main() {
 		{
 			Name:    "read",
 			Aliases: []string{"r"},
-			Usage:   "read <filename> <path>\n\te.g.: yaml read sample.json a.b.c\n\t(default) reads a property from a given yaml file",
+			Usage:   "read <filename> <path>\n\te.g.: yaml read sample.json a.b.c\n\t(default) reads a property from a given yaml file\n",
 			Action:  readProperty,
 		},
+		{
+			Name:    "write",
+			Aliases: []string{"w"},
+			Usage:   "write <filename> <path> <value>\n\te.g.: yaml write sample.json a.b.c 5\n\tupdates a property from a given yaml file, outputs to stdout\n",
+			Action:  writeProperty,
+		},
 	}
 	app.Action = readProperty
 	app.Run(os.Args)
 }
 
 func readProperty(c *cli.Context) {
+
+	var parsedData map[interface{}]interface{}
+
+	readYaml(c, &parsedData)
+
+	if len(c.Args()) == 1 {
+		printYaml(parsedData)
+		os.Exit(0)
+	}
+
+	var paths = parsePath(c.Args()[1])
+
+	printYaml(readMap(parsedData, paths[0], paths[1:len(paths)]))
+}
+
+func writeProperty(c *cli.Context) {
 	var parsedData map[interface{}]interface{}
 	readYaml(c, &parsedData)
 
-	var path = c.Args()[1]
+	if len(c.Args()) < 3 {
-	var paths = strings.Split(path, ".")
+		log.Fatalf("Must provide <filename> <path_to_update> <value>")
+	}
 
-	fmt.Println(readMap(parsedData, paths[0], paths[1:len(paths)]))
+	var paths = parsePath(c.Args()[1])
+
+	write(parsedData, paths[0], paths[1:len(paths)], getValue(c.Args()[2]))
+
+	printYaml(parsedData)
+}
+
+func getValue(argument string) interface{} {
+	var value, err interface{}
+	var inQuotes = 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
+		}
+		return argument
+	}
+	return argument[1 : len(argument)-1]
+}
+
+func printYaml(context interface{}) {
+	out, err := yaml.Marshal(context)
+	if err != nil {
+		log.Fatalf("error printing yaml: %v", err)
+	}
+	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
+	fmt.Println(strings.Trim(outStr, "\n "))
 }
 
 func readYaml(c *cli.Context, parsedData *map[interface{}]interface{}) {
@@ -43,11 +98,6 @@ func readYaml(c *cli.Context, parsedData *map[interface{}]interface{}) {
 	}
 	var rawData = readFile(c.Args()[0])
 
-	if len(c.Args()) == 1 {
-		fmt.Println(string(rawData[:]))
-		os.Exit(0)
-	}
-
 	err := yaml.Unmarshal([]byte(rawData), &parsedData)
 	if err != nil {
 		log.Fatalf("error: %v", err)
@@ -61,32 +111,3 @@ func readFile(filename string) []byte {
 	}
 	return rawData
 }
-
-func readMap(context map[interface{}]interface{}, head string, tail []string) interface{} {
-	value := context[head]
-	if len(tail) > 0 {
-		return recurse(value, tail[0], tail[1:len(tail)])
-	}
-	return value
-}
-
-func recurse(value interface{}, head string, tail []string) interface{} {
-	switch value.(type) {
-	case []interface{}:
-		index, err := strconv.ParseInt(head, 10, 64)
-		if err != nil {
-			log.Fatalf("Error accessing array: %v", err)
-		}
-		return readArray(value.([]interface{}), index, tail)
-	default:
-		return readMap(value.(map[interface{}]interface{}), head, tail)
-	}
-}
-
-func readArray(array []interface{}, head int64, tail []string) interface{} {
-	value := array[head]
-	if len(tail) > 0 {
-		return recurse(value, tail[0], tail[1:len(tail)])
-	}
-	return value
-}

yaml_test.go

@@ -1,41 +1,22 @@
 package main
 
 import (
-	"fmt"
-	"gopkg.in/yaml.v2"
-	"os"
 	"testing"
 )
 
-var rawData = `
+var getValueTests = []struct {
-a: Easy!
+	argument        string
-b:
+	expectedResult  interface{}
-  c: 2
+	testDescription string
-  d: [3, 4]
+}{
-`
+	{"true", true, "boolean"},
-
+	{"\"true\"", "true", "boolean as string"},
-var parsedData map[interface{}]interface{}
+	{"3.4", 3.4, "number"},
-
+	{"\"3.4\"", "3.4", "number as string"},
-func TestMain(m *testing.M) {
-	err := yaml.Unmarshal([]byte(rawData), &parsedData)
-	if err != nil {
-		fmt.Println("Error parsing yaml: %v", err)
-		os.Exit(1)
-	}
-
-	os.Exit(m.Run())
 }
 
-func TestReadMap_simple(t *testing.T) {
+func TestGetValue(t *testing.T) {
-	result := readMap(parsedData, "b", []string{"c"})
+	for _, tt := range getValueTests {
-	if result != 2 {
+		assertResultWithContext(t, tt.expectedResult, getValue(tt.argument), tt.testDescription)
-		t.Error("Excpted 2 but got ", result)
-	}
-}
-
-func TestReadMap_array(t *testing.T) {
-	result := readMap(parsedData, "b", []string{"d", "1"})
-	if result != 4 {
-		t.Error("Excpted 4 but got ", result)
 	}
 }