preserving ordering in arrays.

cmd/yamltool/diff.go

@@ -45,7 +45,8 @@ func subtract(yaml2 yaml.MapSlice, yaml1 yaml.MapSlice) yaml.MapSlice {
 				v1set[strval(v)] = true
 			}
 			s := make([]any, 0)
-			for k2, _ := range v2set {
+			for _, v2value := range v2.([]any) {
+				k2 := strval(v2value)
 				if v1set[k2] {
 					if VERBOSITY == 2 {
 						s = append(s, "<UNMODIFIED>")
@@ -77,8 +78,14 @@ func diff(cmd *cobra.Command, args []string) error {
 	file1 := args[0]
 	file2 := args[1]
 
-	yaml1 := parse(read(file1))
+	yaml1, err := parse(read(file1))
-	yaml2 := parse(read(file2))
+	if err != nil {
+		panic(fmt.Errorf("%s: %w", file1, err))
+	}
+	yaml2, err := parse(read(file2))
+	if err != nil {
+		panic(fmt.Errorf("%s: %w", file2, err))
+	}
 
 	diff1 := subtract(yaml2, yaml1)
 	diff2 := make(yaml.MapSlice, 0)

cmd/yamltool/merge.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"github.com/goccy/go-yaml"
 	"github.com/spf13/cobra"
 	"os"
@@ -53,7 +54,10 @@ func mergeMap(yaml1 yaml.MapSlice, yaml2 yaml.MapSlice) yaml.MapSlice {
 func merge(cmd *cobra.Command, args []string) error {
 	res := make(yaml.MapSlice, 0)
 	for _, arg := range args {
-		config := parse(read(arg))
+		config, err := parse(read(arg))
+		if err != nil {
+			return fmt.Errorf("%s: %w", arg, err)
+		}
 		res = mergeMap(res, config)
 	}
 	encode(os.Stdout, res)

cmd/yamltool/parse.go

@@ -14,13 +14,13 @@ func read(file string) []byte {
 	return data
 }
 
-func parse(data []byte) yaml.MapSlice {
+func parse(data []byte) (yaml.MapSlice, error) {
 	var result yaml.MapSlice
 	decoder := yaml.NewDecoder(bytes.NewReader(data),
 		yaml.UseOrderedMap())
 	err := decoder.Decode(&result)
 	if err != nil {
-		panic(err)
+		return nil, err
 	}
-	return result
+	return result, nil
 }