Implement --diff-args (#959)

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

pkg/app/app.go

@@ -1369,11 +1369,17 @@ func (a *App) apply(r *Run, c ApplyConfigProvider) (bool, bool, []error) {
 		PostRenderer:      c.PostRenderer(),
 	}
 
+	// join --args and --diff-args together to one string.
+	args := strings.Join([]string{c.Args(), c.DiffArgs()}, " ")
+	helm.SetExtraArgs(argparser.GetArgs(args, r.state)...)
+
 	infoMsg, releasesToBeUpdated, releasesToBeDeleted, errs := r.diff(false, detailedExitCode, c, diffOpts)
 	if len(errs) > 0 {
 		return false, false, errs
 	}
 
+	helm.SetExtraArgs()
+
 	var toDelete []state.ReleaseSpec
 	for _, r := range releasesToBeDeleted {
 		toDelete = append(toDelete, r)
@@ -1586,7 +1592,8 @@ func (a *App) diff(r *Run, c DiffConfigProvider) (*string, bool, bool, []error)
 	ok, errs := a.withNeeds(r, c, true, func(st *state.HelmState) []error {
 		helm := r.helm
 
-		helm.SetExtraArgs(argparser.GetArgs(c.Args(), r.state)...)
+		args := strings.Join([]string{c.Args(), c.DiffArgs()}, " ")
+		helm.SetExtraArgs(argparser.GetArgs(args, r.state)...)
 
 		var errs []error
 
@@ -1610,6 +1617,7 @@ func (a *App) diff(r *Run, c DiffConfigProvider) (*string, bool, bool, []error)
 		}
 		infoMsg, updated, deleted, errs = filtered.diff(true, c.DetailedExitcode(), c, opts)
 
+		helm.SetExtraArgs(argparser.GetArgs(c.Args(), r.state)...)
 		return errs
 	})
 

pkg/app/app_test.go

@@ -2215,6 +2215,7 @@ type applyConfig struct {
 	stripTrailingCR        bool
 	interactive            bool
 	skipDiffOnInstall      bool
+	diffArgs               string
 	logger                 *zap.SugaredLogger
 	wait                   bool
 	waitForJobs            bool
@@ -2348,6 +2349,10 @@ func (a applyConfig) SkipDiffOnInstall() bool {
 	return a.skipDiffOnInstall
 }
 
+func (a applyConfig) DiffArgs() string {
+	return a.diffArgs
+}
+
 // helmfile-template-only flags
 
 func (a applyConfig) IncludeCRDs() bool {

pkg/app/config.go

@@ -79,6 +79,8 @@ type ApplyConfigProvider interface {
 	SkipCleanup() bool
 	SkipDiffOnInstall() bool
 
+	DiffArgs() string
+
 	DAGConfig
 
 	concurrencyConfig
@@ -130,6 +132,7 @@ type DiffConfigProvider interface {
 	NoHooks() bool
 	SuppressDiff() bool
 	SkipDiffOnInstall() bool
+	DiffArgs() string
 
 	DAGConfig
 

pkg/app/diff_test.go

@@ -16,6 +16,7 @@ import (
 
 type diffConfig struct {
 	args                   string
+	diffArgs               string
 	values                 []string
 	retainValuesFiles      bool
 	set                    []string
@@ -47,6 +48,10 @@ func (a diffConfig) Args() string {
 	return a.args
 }
 
+func (a diffConfig) DiffArgs() string {
+	return a.diffArgs
+}
+
 func (a diffConfig) Values() []string {
 	return a.values
 }