fix: add tests for comments, multiline, alias features

When round-tripping helm yaml, we want comments to be preserved.
Multiline strings should retain their formatting (this is to allow
for, for example, scripts in k8s commands). Aliases should be preserved,
and followed, both for mappings and scalars.

Author: bewinsnw

pkg/argocd/update_test.go

@@ -2335,6 +2335,112 @@ image:
 		assert.Error(t, err)
 		assert.Equal(t, "unexpected type ScalarNode for key attributes", err.Error())
 	})
+
+	t.Run("Aliases, comments, and multiline strings are preserved", func(t *testing.T) {
+		expected := `
+image:
+    attributes:
+        name: &repo repo-name
+        tag: v2.0.0
+        # this is a comment
+        multiline: |
+            one
+            two
+            three
+        alias: *repo
+`
+
+		inputData := []byte(`
+image:
+    attributes:
+        name: &repo repo-name
+        tag: v1.0.0
+        # this is a comment
+        multiline: |
+            one
+            two
+            three
+        alias: *repo
+`)
+		input := yaml.Node{}
+		err := yaml.Unmarshal(inputData, &input)
+		require.NoError(t, err)
+
+		key := "image.attributes.tag"
+		value := "v2.0.0"
+
+		err = setHelmValue(&input, key, value)
+		require.NoError(t, err)
+
+		output, err := yaml.Marshal(&input)
+		require.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(string(output)))
+	})
+
+	t.Run("Aliases to mappings are followed", func(t *testing.T) {
+		expected := `
+global:
+    attributes: &attrs
+        name: &repo repo-name
+        tag: v2.0.0
+image:
+    attributes: *attrs
+`
+
+		inputData := []byte(`
+global:
+    attributes: &attrs
+        name: &repo repo-name
+        tag: v1.0.0
+image:
+    attributes: *attrs
+`)
+		input := yaml.Node{}
+		err := yaml.Unmarshal(inputData, &input)
+		require.NoError(t, err)
+
+		key := "image.attributes.tag"
+		value := "v2.0.0"
+
+		err = setHelmValue(&input, key, value)
+		require.NoError(t, err)
+
+		output, err := yaml.Marshal(&input)
+		require.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(string(output)))
+	})
+
+	t.Run("Aliases to scalars are followed", func(t *testing.T) {
+		expected := `
+image:
+    attributes:
+        name: repo-name
+        version: &ver v2.0.0
+        tag: *ver
+`
+
+		inputData := []byte(`
+image:
+    attributes:
+        name: repo-name
+        version: &ver v1.0.0
+        tag: *ver
+`)
+		input := yaml.Node{}
+		err := yaml.Unmarshal(inputData, &input)
+		require.NoError(t, err)
+
+		key := "image.attributes.tag"
+		value := "v2.0.0"
+
+		err = setHelmValue(&input, key, value)
+		require.NoError(t, err)
+
+		output, err := yaml.Marshal(&input)
+		require.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(string(output)))
+	})
+
 }
 
 func Test_GetWriteBackConfig(t *testing.T) {