From 1f7f1b0defeb8e10fafb44657387cc556025d9e9 Mon Sep 17 00:00:00 2001
From: Mike Farah <mikefarah@gmail.com>
Date: Sun, 5 Jan 2020 17:28:24 +1300
Subject: [PATCH] Merge arrays!

---
 Upgrade Notes                | 10 ++++++++++
 commands_test.go             | 18 +++++-------------
 examples/sample_array_2.yaml |  3 ++-
 pkg/yqlib/lib.go             | 11 ++++++++++-
 yq.go                        |  4 ++--
 5 files changed, 29 insertions(+), 17 deletions(-)
 create mode 100644 Upgrade Notes

diff --git a/Upgrade Notes b/Upgrade Notes
new file mode 100644
index 0000000..153ebf5
--- /dev/null
+++ b/Upgrade Notes	
@@ -0,0 +1,10 @@
+# New Features
+  - Keeps comments and formatting (e.g. inline arrays)!
+  - Handles anchors!
+  - Can specify yaml tags (e.g. !!int)
+
+# Update scripts file format has changed
+
+# Merge command
+- autocreates missing entries in target by default, new flag to turn that off.
+
diff --git a/commands_test.go b/commands_test.go
index 4f73533..91b9cff 100644
--- a/commands_test.go
+++ b/commands_test.go
@@ -1342,34 +1342,26 @@ c:
 	test.AssertResult(t, expectedOutput, result.Output)
 }
 
-func xTestMergeAppendCmd(t *testing.T) {
+func TestMergeAppendCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "merge --append examples/data1.yaml examples/data2.yaml")
+	result := test.RunCmd(cmd, "merge --autocreate=false --append examples/data1.yaml examples/data2.yaml")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
 	expectedOutput := `a: simple
-b:
-- 1
-- 2
-- 3
-- 4
+b: [1, 2, 3, 4]
 c:
   test: 1
 `
 	test.AssertResult(t, expectedOutput, result.Output)
 }
-func xTestMergeArraysCmd(t *testing.T) {
+func TestMergeArraysCmd(t *testing.T) {
 	cmd := getRootCommand()
 	result := test.RunCmd(cmd, "merge --append examples/sample_array.yaml examples/sample_array_2.yaml")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
-	expectedOutput := `- 1
-- 2
-- 3
-- 4
-- 5
+	expectedOutput := `[1, 2, 3, 4, 5]
 `
 	test.AssertResult(t, expectedOutput, result.Output)
 }
diff --git a/examples/sample_array_2.yaml b/examples/sample_array_2.yaml
index b32037f..e83ee7a 100644
--- a/examples/sample_array_2.yaml
+++ b/examples/sample_array_2.yaml
@@ -1 +1,2 @@
-[4,5]
\ No newline at end of file
+- 4
+- 5
\ No newline at end of file
diff --git a/pkg/yqlib/lib.go b/pkg/yqlib/lib.go
index dbf1918..1868981 100644
--- a/pkg/yqlib/lib.go
+++ b/pkg/yqlib/lib.go
@@ -34,11 +34,20 @@ func DebugNode(value *yaml.Node) {
 }
 
 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:
-			sb.WriteString(fmt.Sprintf("[%v]", path))
+			if appendArrays {
+				sb.WriteString("[+]")
+			} else {
+				sb.WriteString(fmt.Sprintf("[%v]", path))
+			}
+
 		default:
 			sb.WriteString(fmt.Sprintf("%v", path))
 		}
diff --git a/yq.go b/yq.go
index 22cace4..a133379 100644
--- a/yq.go
+++ b/yq.go
@@ -238,7 +238,7 @@ Note that if you set both flags only overwrite will take effect.
 	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(&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)")
 	return cmdMerge
@@ -435,7 +435,7 @@ func mergeProperties(cmd *cobra.Command, args []string) error {
 			return errorProcessingFile
 		}
 		for _, matchingNode := range matchingNodes {
-			mergePath := yqlib.PathStackToString(matchingNode.PathStack)
+			mergePath := yqlib.MergePathStackToString(matchingNode.PathStack, appendFlag)
 			updateCommands = append(updateCommands, yqlib.UpdateCommand{Command: "update", Path: mergePath, Value: matchingNode.Node, Overwrite: overwriteFlag})
 		}
 	}