Maintain order

Author: Mike Farah

data_navigator.go

@@ -2,21 +2,34 @@ package main
 
 import (
 	// "fmt"
+	"github.com/mikefarah/yaml/Godeps/_workspace/src/gopkg.in/yaml.v2"
 	"strconv"
 )
 
-func write(context map[interface{}]interface{}, head string, tail []string, value interface{}) {
+func entryInSlice(context yaml.MapSlice, key interface{}) *yaml.MapItem {
+	for idx := range context {
+		var entry = &context[idx]
+		if entry.Key == key {
+			return entry
+		}
+	}
+	return nil
+}
+
+func write(context yaml.MapSlice, head string, tail []string, value interface{}) {
 	if len(tail) == 0 {
-		context[head] = value
+		var entry = entryInSlice(context, head)
+		entry.Value = value
 	} else {
 		// e.g. if updating a.b.c, we need to get the 'b', this could be a map or an array
 		var parent = readMap(context, head, tail[0:len(tail)-1])
 		switch parent.(type) {
-		case map[interface{}]interface{}:
-			toUpdate := parent.(map[interface{}]interface{})
+		case yaml.MapSlice:
+			toUpdate := parent.(yaml.MapSlice)
 			// b is a map, update the key 'c' to the supplied value
 			key := (tail[len(tail)-1])
-			toUpdate[key] = value
+			toUpdateEntry := entryInSlice(toUpdate, key)
+			toUpdateEntry.Value = value
 		case []interface{}:
 			toUpdate := parent.([]interface{})
 			// b is an array, update it at index 'c' to the supplied value
@@ -31,22 +44,26 @@ func write(context map[interface{}]interface{}, head string, tail []string, valu
 	}
 }
 
-func readMap(context map[interface{}]interface{}, head string, tail []string) interface{} {
+func readMap(context yaml.MapSlice, head string, tail []string) interface{} {
 	if head == "*" {
 		return readMapSplat(context, tail)
 	}
-	value := context[head]
+	entry := entryInSlice(context, head)
+	var value interface{}
+	if entry != nil {
+		value = entry.Value
+	}
 	return calculateValue(value, tail)
 }
 
-func readMapSplat(context map[interface{}]interface{}, tail []string) interface{} {
+func readMapSplat(context yaml.MapSlice, tail []string) interface{} {
 	var newArray = make([]interface{}, len(context))
 	var i = 0
-	for _, value := range context {
+	for _, entry := range context {
 		if len(tail) > 0 {
-			newArray[i] = recurse(value, tail[0], tail[1:len(tail)])
+			newArray[i] = recurse(entry.Value, tail[0], tail[1:len(tail)])
 		} else {
-			newArray[i] = value
+			newArray[i] = entry.Value
 		}
 		i++
 	}
@@ -64,8 +81,8 @@ func recurse(value interface{}, head string, tail []string) interface{} {
 			die("Error accessing array: %v", err)
 		}
 		return readArray(value.([]interface{}), index, tail)
-	case map[interface{}]interface{}:
-		return readMap(value.(map[interface{}]interface{}), head, tail)
+	case yaml.MapSlice:
+		return readMap(value.(yaml.MapSlice), head, tail)
 	default:
 		return nil
 	}

data_navigator_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"github.com/mikefarah/yaml/Godeps/_workspace/src/gopkg.in/yaml.v2"
 	"sort"
 	"testing"
 )
@@ -107,16 +108,26 @@ e:
 	assertResult(t, "[Fred Sam]", fmt.Sprintf("%v", readMap(data, "e", []string{"*", "name"})))
 }
 
+func TestWrite_really_simple(t *testing.T) {
+	var data = parseData(`
+    b: 2
+`)
+
+	write(data, "b", []string{}, "4")
+	b := entryInSlice(data, "b").Value
+	assertResult(t, "4", b)
+}
+
 func TestWrite_simple(t *testing.T) {
 	var data = parseData(`
 b:
   c: 2
 `)
 
 	write(data, "b", []string{"c"}, "4")
-
-	b := data["b"].(map[interface{}]interface{})
-	assertResult(t, "4", b["c"].(string))
+	b := entryInSlice(data, "b").Value.(yaml.MapSlice)
+	c := entryInSlice(b, "c").Value
+	assertResult(t, "4", c)
 }
 
 func TestWrite_array(t *testing.T) {
@@ -127,7 +138,7 @@ b:
 
 	write(data, "b", []string{"0"}, "bb")
 
-	b := data["b"].([]interface{})
+	b := entryInSlice(data, "b").Value.([]interface{})
 	assertResult(t, "bb", b[0].(string))
 }
 
@@ -138,6 +149,6 @@ b:
 `)
 	write(data, "b", []string{}, "4")
 
-	b := data["b"]
+	b := entryInSlice(data, "b").Value
 	assertResult(t, "4", fmt.Sprintf("%v", b))
 }

json_converter.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"github.com/mikefarah/yaml/Godeps/_workspace/src/gopkg.in/yaml.v2"
 )
 
 func fromJSONBytes(jsonBytes []byte, parsedData *map[interface{}]interface{}) {
@@ -55,11 +56,11 @@ func toJSON(context interface{}) interface{} {
 			newArray[index] = toJSON(value)
 		}
 		return newArray
-	case map[interface{}]interface{}:
-		oldMap := context.(map[interface{}]interface{})
+	case yaml.MapSlice:
+		oldMap := context.(yaml.MapSlice)
 		newMap := make(map[string]interface{})
-		for key, value := range oldMap {
-			newMap[key.(string)] = toJSON(value)
+		for _, entry := range oldMap {
+			newMap[entry.Key.(string)] = toJSON(entry.Value)
 		}
 		return newMap
 	default:

order.yaml

@@ -0,0 +1,2 @@
+version: 3
+application: MyApp

order.yml

@@ -0,0 +1,6 @@
+version: '2'
+services:
+  test:
+    image: ubuntu:14.04
+    stdin_open: true
+    tty: true

utils_test.go

@@ -7,8 +7,8 @@ import (
 	"testing"
 )
 
-func parseData(rawData string) map[interface{}]interface{} {
-	var parsedData map[interface{}]interface{}
+func parseData(rawData string) yaml.MapSlice {
+	var parsedData yaml.MapSlice
 	err := yaml.Unmarshal([]byte(rawData), &parsedData)
 	if err != nil {
 		fmt.Println("Error parsing yaml: %v", err)

yaml.go

@@ -81,7 +81,7 @@ func readProperty(cmd *cobra.Command, args []string) {
 }
 
 func read(args []string) interface{} {
-	var parsedData map[interface{}]interface{}
+	var parsedData yaml.MapSlice
 
 	readData(args[0], &parsedData, inputJSON)
 
@@ -114,13 +114,14 @@ func updateYaml(args []string) interface{} {
 		writeCommands[args[1]] = parseValue(args[2])
 	}
 
-	var parsedData map[interface{}]interface{}
+	var parsedData yaml.MapSlice
 	readData(args[0], &parsedData, inputJSON)
 
 	for path, value := range writeCommands {
 		var paths = parsePath(path)
 		write(parsedData, paths[0], paths[1:len(paths)], value)
 	}
+
 	return parsedData
 }
 

yaml_test.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"testing"
 )
 
@@ -26,8 +27,21 @@ func TestRead(t *testing.T) {
 	assertResult(t, 2, result)
 }
 
+func TestOrder(t *testing.T) {
+	result := read([]string{"order.yaml"})
+	formattedResult := yamlToString(result)
+	assertResult(t,
+		`version: 3
+application: MyApp`,
+		formattedResult)
+}
+
 func TestUpdateYaml(t *testing.T) {
-	updateYaml([]string{"sample.yaml", "b.c", "3"})
+	result := updateYaml([]string{"sample.yaml", "b.c", "3"})
+	formattedResult := fmt.Sprintf("%v", result)
+	assertResult(t,
+		"[{a Easy! as one two three} {b [{c 3} {d [3 4]} {e [[{name fred} {value 3}] [{name sam} {value 4}]]}]}]",
+		formattedResult)
 }
 
 func TestUpdateYaml_WithScript(t *testing.T) {