Copy comments from function inputs to function outputs.

kyaml/comments/comments.go

@@ -37,6 +37,18 @@ func (c *copier) VisitScalar(s walk.Sources, _ *openapi.ResourceSchema) (*yaml.R
 func (c *copier) VisitList(s walk.Sources, _ *openapi.ResourceSchema, _ walk.ListKind) (
 	*yaml.RNode, error) {
 	copy(s.Dest(), s.Origin())
+	destItems := s.Dest().Content()
+	originItems := s.Origin().Content()
+
+	for i := 0; i < len(destItems) && i < len(originItems); i++ {
+		dest := destItems[i]
+		origin := originItems[i]
+
+		if dest.Value == origin.Value {
+			copy(yaml.NewRNode(dest), yaml.NewRNode(origin))
+		}
+	}
+
 	return s.Dest(), nil
 }
 
@@ -45,13 +57,13 @@ func copy(from, to *yaml.RNode) {
 	if from == nil || to == nil {
 		return
 	}
-	if from.Document().LineComment != "" {
+	if to.Document().LineComment == "" {
 		to.Document().LineComment = from.Document().LineComment
 	}
-	if from.Document().HeadComment != "" {
+	if to.Document().HeadComment == "" {
 		to.Document().HeadComment = from.Document().HeadComment
 	}
-	if from.Document().FootComment != "" {
+	if to.Document().FootComment == "" {
 		to.Document().FootComment = from.Document().FootComment
 	}
 }

kyaml/comments/comments_test.go

@@ -4,6 +4,7 @@
 package comments
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -11,7 +12,15 @@ import (
 )
 
 func TestCopyComments(t *testing.T) {
-	from, err := yaml.Parse(`# A
+	testCases := []struct {
+		name     string
+		from     string
+		to       string
+		expected string
+	}{
+		{
+			name: "copy_comments",
+			from: `# A
 #
 # B
 
@@ -22,31 +31,13 @@ spec: # comment 1
   # comment 2
   replicas: 3 # comment 3
   # comment 4
-`)
-	if !assert.NoError(t, err) {
-		t.FailNow()
-	}
-
-	to, err := yaml.Parse(`apiVersion: apps/v1
+`,
+			to: `apiVersion: apps/v1
 kind: Deployment
 spec:
   replicas: 4
-`)
-	if !assert.NoError(t, err) {
-		t.FailNow()
-	}
-
-	err = CopyComments(from, to)
-	if !assert.NoError(t, err) {
-		t.FailNow()
-	}
-
-	actual, err := to.String()
-	if !assert.NoError(t, err) {
-		t.FailNow()
-	}
-
-	expected := `# A
+`,
+			expected: `# A
 #
 # B
 
@@ -57,9 +48,274 @@ spec: # comment 1
   # comment 2
   replicas: 4 # comment 3
   # comment 4
-`
+`,
+		},
 
-	if !assert.Equal(t, expected, actual) {
-		t.FailNow()
+		{
+			name: "associative_list",
+			from: `
+apiVersion: apps/v1
+kind: Deployment
+spec:
+  template:
+    spec:
+      containers:
+      - name: foo
+        image: bar # comment 1
+`,
+			to: `
+apiVersion: apps/v1
+kind: Deployment
+spec:
+  template:
+    spec:
+      containers:
+      - name: foo
+        image: bar
+`,
+			expected: `
+apiVersion: apps/v1
+kind: Deployment
+spec:
+  template:
+    spec:
+      containers:
+      - name: foo
+        image: bar # comment 1
+`,
+		},
+
+		{
+			name: "keep_comments",
+			from: `# A
+#
+# B
+
+# C
+apiVersion: apps/v1
+kind: Deployment
+spec: # comment 1
+  # comment 2
+  replicas: 3 # comment 3
+  # comment 4
+`,
+			to: `apiVersion: apps/v1
+kind: Deployment
+spec:
+  replicas: 4 # comment 5
+`,
+			expected: `# A
+#
+# B
+
+# C
+apiVersion: apps/v1
+kind: Deployment
+spec: # comment 1
+  # comment 2
+  replicas: 4 # comment 5
+  # comment 4
+`,
+		},
+
+		{
+			name: "copy_item_comments",
+			from: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a # comment
+`,
+			to: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a
+`,
+			expected: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a # comment
+`,
+		},
+
+		{
+			name: "copy_item_comments_2",
+			from: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+# comment
+- a
+`,
+			to: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a
+`,
+			expected: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+# comment
+- a
+`,
+		},
+
+		{
+			name: "copy_item_comments_middle",
+			from: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a
+- b # comment
+- c
+`,
+			to: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- d
+- b
+- e
+`,
+			expected: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- d
+- b # comment
+- e
+`,
+		},
+
+		{
+			name: "copy_item_comments_moved",
+			from: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a
+- b # comment
+- c
+`,
+			to: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a
+- c
+- b
+`,
+			expected: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a
+- c
+- b
+`,
+		},
+
+		{
+			name: "copy_item_comments_no_match",
+			from: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a # comment
+`,
+			to: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- b
+`,
+			expected: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- b
+`,
+		},
+
+		{
+			name: "copy_item_comments_add",
+			from: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a # comment
+`,
+			to: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a
+- b
+`,
+			expected: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a # comment
+- b
+`,
+		},
+
+		{
+			name: "copy_item_comments_remove",
+			from: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a # comment
+- b
+`,
+			to: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a
+`,
+			expected: `
+apiVersion: apps/v1
+kind: Deployment
+items:
+- a # comment
+`,
+		},
+	}
+
+	for i := range testCases {
+		tc := testCases[i]
+		t.Run(tc.name, func(t *testing.T) {
+			from, err := yaml.Parse(tc.from)
+			if !assert.NoError(t, err) {
+				t.FailNow()
+			}
+
+			to, err := yaml.Parse(tc.to)
+			if !assert.NoError(t, err) {
+				t.FailNow()
+			}
+
+			err = CopyComments(from, to)
+			if !assert.NoError(t, err) {
+				t.FailNow()
+			}
+
+			actual, err := to.String()
+			if !assert.NoError(t, err) {
+				t.FailNow()
+			}
+
+			if !assert.Equal(t, strings.TrimSpace(tc.expected), strings.TrimSpace(actual)) {
+				t.FailNow()
+			}
+		})
 	}
 }