test(internal/yaml): add tests (#3105)

Add tests for functions in package yaml.

Author: julieqiu

internal/yaml/ref_test.go

@@ -0,0 +1,72 @@
+// Copyright 2025 Google LLC
+//
+// 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
+//
+//     https://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 yaml
+
+import (
+	"strings"
+	"testing"
+
+	"gopkg.in/yaml.v3"
+)
+
+type refConfig struct {
+	Ref RefString `yaml:"ref"`
+}
+
+func TestRefStringMarshal(t *testing.T) {
+	input := &refConfig{Ref: RefString("some/path")}
+	data, err := yaml.Marshal(input)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(string(data), "!REF") {
+		t.Errorf("Marshal() output missing !REF tag: %s", string(data))
+	}
+}
+
+func TestRefStringUnmarshal(t *testing.T) {
+	data := "ref: !REF some/path\n"
+	var got refConfig
+	if err := yaml.Unmarshal([]byte(data), &got); err != nil {
+		t.Fatal(err)
+	}
+	if got.Ref != "some/path" {
+		t.Errorf("Unmarshal() ref = %q, want %q", got.Ref, "some/path")
+	}
+}
+
+func TestRefStringUnmarshalError(t *testing.T) {
+	data := "ref: some/path\n"
+	var got refConfig
+	err := yaml.Unmarshal([]byte(data), &got)
+	if err == nil {
+		t.Error("Unmarshal() expected error for missing !REF tag")
+	}
+}
+
+func TestRefStringRoundTrip(t *testing.T) {
+	input := &refConfig{Ref: RefString("some/path")}
+	data, err := yaml.Marshal(input)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var got refConfig
+	if err := yaml.Unmarshal(data, &got); err != nil {
+		t.Fatal(err)
+	}
+	if got.Ref != input.Ref {
+		t.Errorf("round-trip ref = %q, want %q", got.Ref, input.Ref)
+	}
+}

internal/yaml/yaml_test.go

@@ -0,0 +1,89 @@
+// Copyright 2025 Google LLC
+//
+// 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
+//
+//     https://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 yaml
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+type testConfig struct {
+	Name    string `yaml:"name"`
+	Version string `yaml:"version"`
+}
+
+func TestUnmarshal(t *testing.T) {
+	got, err := Unmarshal[testConfig]([]byte("name: test\nversion: v1.0.0\n"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := &testConfig{Name: "test", Version: "v1.0.0"}
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Errorf("mismatch (-want +got):\n%s", diff)
+	}
+}
+
+func TestUnmarshalError(t *testing.T) {
+	_, err := Unmarshal[testConfig]([]byte("name: [invalid"))
+	if err == nil {
+		t.Error("Unmarshal() expected error for invalid YAML")
+	}
+}
+
+func TestMarshal(t *testing.T) {
+	input := &testConfig{Name: "test", Version: "v1.0.0"}
+	data, err := Marshal(input)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err := Unmarshal[testConfig](data)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if diff := cmp.Diff(input, got); diff != "" {
+		t.Errorf("mismatch (-want +got):\n%s", diff)
+	}
+}
+
+func TestReadWrite(t *testing.T) {
+	want := &testConfig{Name: "test", Version: "v1.0.0"}
+	path := filepath.Join(t.TempDir(), "test.yaml")
+	if err := Write(path, want); err != nil {
+		t.Fatal(err)
+	}
+	got, err := Read[testConfig](path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Errorf("mismatch (-want +got):\n%s", diff)
+	}
+}
+
+func TestReadError(t *testing.T) {
+	_, err := Read[testConfig]("/nonexistent/path/file.yaml")
+	if err == nil {
+		t.Error("Read() expected error for nonexistent file")
+	}
+}
+
+func TestWriteError(t *testing.T) {
+	err := Write("/nonexistent/path/file.yaml", &testConfig{Name: "test"})
+	if err == nil {
+		t.Error("Write() expected error for invalid path")
+	}
+}