Fix crash on empty helm render: treat no-output chart as no-op

integration_test.go

@@ -265,6 +265,21 @@ func TestIntegration(t *testing.T) {
 		chart:       "./testdata/charts/importvalues",
 	})
 
+	// SAVE_SNAPSHOT=1 go1.25 test -run ^TestIntegration/empty_render_no_op$ ./
+	// Tests that a chart whose templates all render to nothing (e.g. gated behind a falsy
+	// conditional) is treated as a no-op rather than causing an assertion error.
+	// See https://github.com/helmfile/chartify/issues/206
+	runTest(t, integrationTestCase{
+		description: "empty render no op",
+		release:     "myapp",
+		chart:       "./testdata/charts/emptychart",
+		opts: ChartifyOpts{
+			// OverrideNamespace ensures ReplaceWithRendered is called even though
+			// no Patches/Injectors are configured, exercising the empty-render path.
+			OverrideNamespace: "test-ns",
+		},
+	})
+
 	//
 	// Kubernets Manifests
 	//

replace.go

@@ -132,6 +132,23 @@ func (r *Runner) ReplaceWithRendered(name, chartName, chartPath string, o Replac
 		return nil, fmt.Errorf("unable to read helm output dir entries: %w", err)
 	}
 
+	// When the chart renders no resources, helm template --output-dir produces an empty
+	// directory. Treat this as a no-op: remove original content dirs so that subsequent
+	// helm processing also sees no resources, clean up the temp output dir, and return
+	// an empty file list with no error.
+	if len(helmOutputDirEntries) == 0 {
+		if err := os.RemoveAll(helmOutputDir); err != nil {
+			return nil, fmt.Errorf("cleaning up empty helm output dir: %v", err)
+		}
+		for _, d := range ContentDirs {
+			origDir := filepath.Join(chartPath, d)
+			if err := os.RemoveAll(origDir); err != nil {
+				return nil, err
+			}
+		}
+		return nil, nil
+	}
+
 	// This directory contains templates/ and charts/SUBCHART/templates
 	var chartOutputDir string
 

testdata/charts/emptychart/Chart.yaml

@@ -0,0 +1,6 @@
+apiVersion: v2
+name: emptychart
+description: A Helm chart whose templates are all conditionally disabled, used to test empty render handling
+type: application
+version: 0.1.0
+appVersion: "1.0.0"

testdata/charts/emptychart/templates/configmap.yaml

@@ -0,0 +1,8 @@
+{{- if .Values.enabled }}
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ .Release.Name }}-cm
+data:
+  hello: world
+{{- end }}

testdata/charts/emptychart/values.yaml

@@ -0,0 +1,3 @@
+# When enabled is false (the default), this chart renders no resources,
+# which exercises the empty-render code path in chartify.
+enabled: false

testdata/integration/testcases/empty_render_no_op/want

@@ -0,0 +1 @@
+