Add tests for stringCollectionsDeepCopy

Signed-off-by: Michał Słapek <28485371+mslapek@users.noreply.github.com>

pkg/chartutil/coalesce.go

@@ -145,33 +145,6 @@ func coalesceGlobals(printf printFn, dest, src map[string]interface{}, prefix st
 	dest[GlobalKey] = dg
 }
 
-func copyMap(src map[string]interface{}) map[string]interface{} {
-	m := make(map[string]interface{}, len(src))
-	for k, v := range src {
-		m[k] = v
-	}
-	return m
-}
-
-// stringCollectionsDeepCopy makes deep copy for string maps and lists.
-// For other types performs shallow copy.
-func stringCollectionsDeepCopy(src any) any {
-	switch t := src.(type) {
-	case map[string]any:
-		r := make(map[string]interface{}, len(t))
-		for k, v := range t {
-			r[k] = stringCollectionsDeepCopy(v)
-		}
-		return r
-	case []string:
-		r := make([]string, len(t))
-		copy(r, t)
-		return r
-	default:
-		return t
-	}
-}
-
 // coalesceValues builds up a values map for a particular chart.
 //
 // Values in v will override the values in the chart.

pkg/chartutil/coalesce_test.go

@@ -17,7 +17,6 @@ limitations under the License.
 package chartutil
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"testing"
@@ -69,9 +68,7 @@ func assertIsEqualToJSON(t *testing.T, name string, val any, expectedJson []byte
 	if err != nil {
 		t.Fatalf("JSON marshal failed: %v", err)
 	}
-	if !bytes.Equal(j, expectedJson) {
-		t.Errorf("%s contents changed, got: %v", name, string(j))
-	}
+	assert.Equal(t, expectedJson, j)
 }
 
 func TestCoalesceValues(t *testing.T) {

pkg/chartutil/copy.go

@@ -0,0 +1,44 @@
+/*
+Copyright The Helm Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package chartutil
+
+func copyMap(src map[string]interface{}) map[string]interface{} {
+	m := make(map[string]interface{}, len(src))
+	for k, v := range src {
+		m[k] = v
+	}
+	return m
+}
+
+// stringCollectionsDeepCopy makes deep copy for string maps and lists.
+// For other types performs shallow copy.
+func stringCollectionsDeepCopy(src any) any {
+	switch t := src.(type) {
+	case map[string]any:
+		r := make(map[string]interface{}, len(t))
+		for k, v := range t {
+			r[k] = stringCollectionsDeepCopy(v)
+		}
+		return r
+	case []string:
+		r := make([]string, len(t))
+		copy(r, t)
+		return r
+	default:
+		return t
+	}
+}

pkg/chartutil/copy_test.go

@@ -0,0 +1,129 @@
+/*
+Copyright The Helm Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package chartutil
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type Foo struct {
+	Bar   int
+	Ipsum []string
+}
+
+func makeExample() any {
+	return map[string]any{
+		"ab": []string{"hello", "world"},
+		"bc": "qwerty",
+		"cd": &Foo{1000, []string{"blue", "red"}},
+		"nested": map[string]any{
+			"alpha": 5,
+		},
+		"nums": []int{3, 5, 7},
+		"nums map": map[string]int{
+			"a": 2,
+			"b": 4,
+		},
+	}
+}
+
+func TestStringCollectionsDeepCopy(t *testing.T) {
+	tests := []struct {
+		name    string
+		factory func() any
+	}{
+		{
+			"nil",
+			func() any { return nil },
+		},
+		{
+			"[]string",
+			func() any { return []string{"hello", "world"} },
+		},
+		{
+			"[]int",
+			func() any { return []int{2, 4, 6} },
+		},
+		{
+			"map[string]any",
+			func() any {
+				return map[string]any{
+					"ab": []string{"hello", "world"},
+					"bc": "qwerty",
+				}
+			},
+		},
+		{
+			"custom type",
+			func() any {
+				return Foo{1000, []string{"blue", "red"}}
+			},
+		},
+		{
+			"map[string]any with custom type",
+			func() any {
+				return map[string]any{
+					"ab": []string{"hello", "world"},
+					"bc": "qwerty",
+					"cd": Foo{1000, []string{"blue", "red"}},
+				}
+			},
+		},
+		{
+			"complex example", makeExample,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			src := tt.factory()
+			got := stringCollectionsDeepCopy(src)
+
+			assert.Equal(t, tt.factory(), got)
+		})
+	}
+}
+
+func TestStringCollectionsDeepCopyAliasing(t *testing.T) {
+	is := assert.New(t)
+
+	src := makeExample().(map[string]any)
+	got := stringCollectionsDeepCopy(src).(map[string]any)
+
+	got["ab"].([]string)[1] = "globe"
+	is.Equal("world", src["ab"].([]string)[1])
+
+	got["bc"] = "quartz"
+	is.Equal("qwerty", src["bc"])
+
+	got["nested"].(map[string]any)["alpha"] = "9"
+	is.Equal(5, src["nested"].(map[string]any)["alpha"])
+
+	// notice, that Foo is not deep copied
+	got["cd"].(*Foo).Bar = 500
+	got["cd"].(*Foo).Ipsum[0] = "green"
+	is.Equal(500, src["cd"].(*Foo).Bar)
+	is.Equal("green", src["cd"].(*Foo).Ipsum[0])
+
+	// non-any collections are not deep copied
+	got["nums"].([]int)[1] = 10
+	is.Equal(10, src["nums"].([]int)[1])
+
+	got["nums map"].(map[string]int)["b"] = 10
+	is.Equal(10, src["nums map"].(map[string]int)["b"])
+}