fix: whitespace only values.yaml files fail parsing (#1228)

Signed-off-by: MenD32 <[email protected]>

Author: MenD32

pkg/argocd/update.go

@@ -11,6 +11,8 @@ import (
 	"sync"
 	"text/template"
 	"time"
+	"unicode"
+	"unicode/utf8"
 
 	"golang.org/x/exp/slices"
 
@@ -486,7 +488,7 @@ func marshalParamsOverride(app *v1alpha1.Application, originalData []byte) ([]by
 			images := GetImagesAndAliasesFromApplication(app)
 
 			var helmNewValues yaml.Node
-			if len(originalData) == 0 {
+			if isOnlyWhitespace(originalData) {
 				// allow non-exists target file
 				helmNewValues = yaml.Node{
 					Kind:        yaml.DocumentNode,
@@ -874,3 +876,17 @@ func commitChanges(app *v1alpha1.Application, wbc *WriteBackConfig, changeList [
 	}
 	return nil
 }
+
+func isOnlyWhitespace(data []byte) bool {
+	if len(data) == 0 {
+		return true
+	}
+	for i := 0; i < len(data); {
+		r, size := utf8.DecodeRune(data[i:])
+		if !unicode.IsSpace(r) {
+			return false
+		}
+		i += size
+	}
+	return true
+}

pkg/argocd/update_test.go

@@ -2241,6 +2241,72 @@ replicas: 1
 		_, err := marshalParamsOverride(&app, nil)
 		assert.Error(t, err)
 	})
+
+	t.Run("Whitespace only values file from helm source does not cause error", func(t *testing.T) {
+		expected := `
+# auto generated by argocd image updater
+
+nginx:
+  image:
+    tag: v1.0.0
+    name: nginx
+`
+		app := v1alpha1.Application{
+			ObjectMeta: v1.ObjectMeta{
+				Name: "testapp",
+				Annotations: map[string]string{
+					"argocd-image-updater.argoproj.io/image-list":            "nginx=nginx, redis=redis",
+					"argocd-image-updater.argoproj.io/write-back-method":     "git",
+					"argocd-image-updater.argoproj.io/write-back-target":     "helmvalues:./test-values.yaml",
+					"argocd-image-updater.argoproj.io/nginx.helm.image-name": "nginx.image.name",
+					"argocd-image-updater.argoproj.io/nginx.helm.image-tag":  "nginx.image.tag",
+				},
+			},
+			Spec: v1alpha1.ApplicationSpec{
+				Sources: []v1alpha1.ApplicationSource{
+					{
+						Chart: "my-app",
+						Helm: &v1alpha1.ApplicationSourceHelm{
+							ReleaseName: "my-app",
+							ValueFiles:  []string{"$values/some/dir/values.yaml"},
+							Parameters: []v1alpha1.HelmParameter{
+								{
+									Name:        "nginx.image.name",
+									Value:       "nginx",
+									ForceString: true,
+								},
+								{
+									Name:        "nginx.image.tag",
+									Value:       "v1.0.0",
+									ForceString: true,
+								},
+							},
+						},
+						RepoURL:        "https://example.com/example",
+						TargetRevision: "main",
+					},
+				},
+			},
+			Status: v1alpha1.ApplicationStatus{
+				SourceTypes: []v1alpha1.ApplicationSourceType{
+					v1alpha1.ApplicationSourceTypeHelm,
+					"",
+				},
+				Summary: v1alpha1.ApplicationSummary{
+					Images: []string{
+						"nginx:v0.0.0",
+					},
+				},
+			},
+		}
+
+		originalData := []byte(`
+`)
+		yaml, err := marshalParamsOverride(&app, originalData)
+		require.NoError(t, err)
+		assert.NotEmpty(t, yaml)
+		assert.Equal(t, strings.TrimSpace(strings.ReplaceAll(expected, "\t", "  ")), strings.TrimSpace(string(yaml)))
+	})
 }
 
 func Test_SetHelmValue(t *testing.T) {