feat: Add --fail-on-diff-error CLI flag to return non-zero exit code on diff error

README.md

@@ -45,6 +45,7 @@ Flags:
       --base string                        base commitish (default to origin/main)
       --debug                              debug mode
       --exclude string                     exclude regexp (default to none)
+      --fail-on-diff-error                 return non-zero status code if a diff error occurs
       --git-path string                    path of a git binary (default to git)
   -h, --help                               help for run
       --include string                     include regexp (default to all)

cmd/root.go

@@ -28,6 +28,7 @@ type rootFlags struct {
 var RootCmd = &cobra.Command{
 	Use:           "git-kustomize-diff",
 	Short:         "git-kustomize-diff",
+	SilenceUsage:  true,
 	SilenceErrors: false,
 	PersistentPreRun: func(cmd *cobra.Command, args []string) {
 		if cmd.Use == "version" {

cmd/run.go

@@ -36,6 +36,7 @@ type runFlags struct {
 	gitPath                 string
 	debug                   bool
 	allowDirty              bool
+	failOnDiffError         bool
 }
 
 var runCmd = &cobra.Command{
@@ -80,6 +81,14 @@ var runCmd = &cobra.Command{
 
 		printRunResult(dir, opts, res)
 
+		if runOpts.failOnDiffError {
+			for _, v := range res.DiffMap.Results {
+				if _, ok := v.(*gitkustomizediff.DiffError); ok {
+					return fmt.Errorf("fail on diff error")
+				}
+			}
+		}
+
 		return nil
 	},
 }
@@ -96,6 +105,7 @@ func init() {
 	runCmd.PersistentFlags().StringVar(&runOpts.gitPath, "git-path", "", "path of a git binary (default to git)")
 	runCmd.PersistentFlags().BoolVar(&runOpts.debug, "debug", false, "debug mode")
 	runCmd.PersistentFlags().BoolVar(&runOpts.allowDirty, "allow-dirty", false, "allow dirty tree")
+	runCmd.PersistentFlags().BoolVar(&runOpts.failOnDiffError, "fail-on-diff-error", false, "return non-zero status code if a diff error occurs")
 }
 
 func printRunResult(dirPath string, opts gitkustomizediff.RunOpts, res *gitkustomizediff.RunResult) {