pr feedback

compute/metadata/go.mod

@@ -2,4 +2,7 @@ module cloud.google.com/go/compute/metadata
 
 go 1.21
 
-require golang.org/x/sys v0.28.0
+require (
+	github.com/google/go-cmp v0.6.0
+	golang.org/x/sys v0.28.0
+)

compute/metadata/go.sum

@@ -1,2 +1,4 @@
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
 golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

compute/metadata/log_test.go

@@ -0,0 +1,137 @@
+// Copyright 2024 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
+//
+//      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 metadata
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"flag"
+	"io"
+	"log/slog"
+	"net/http"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+var updateGolden = flag.Bool("update-golden", false, "update golden files")
+
+// To update conformance tests in this package run `go test -update_golden`
+func TestMain(m *testing.M) {
+	flag.Parse()
+	os.Exit(m.Run())
+}
+
+func TestLog_httpRequest(t *testing.T) {
+	golden := "httpRequest.log"
+	logger, f := setupLogger(t, golden)
+	ctx := context.Background()
+	request, err := http.NewRequest(http.MethodPost, "https://example.com/computeMetadata/v1/instance/service-accounts/default/token", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	request.Header.Add("foo", "bar")
+	logger.DebugContext(ctx, "msg", "request", httpRequest(request, nil))
+	f.Close()
+	diffTest(t, f.Name(), golden)
+}
+
+func TestLog_httpResponse(t *testing.T) {
+	golden := "httpResponse.log"
+	logger, f := setupLogger(t, golden)
+	ctx := context.Background()
+	body := []byte(`{"access_token":"token","expires_in":600,"token_type":"Bearer"}`)
+	response := &http.Response{
+		StatusCode: 200,
+		Header:     http.Header{"Foo": []string{"bar"}},
+		Body:       io.NopCloser(bytes.NewReader(body)),
+	}
+	logger.DebugContext(ctx, "msg", "response", httpResponse(response, body))
+	f.Close()
+	diffTest(t, f.Name(), golden)
+}
+
+func setupLogger(t *testing.T, golden string) (*slog.Logger, *os.File) {
+	t.Helper()
+	f, err := os.CreateTemp(t.TempDir(), golden)
+	if err != nil {
+		t.Fatal(err)
+	}
+	logger := slog.New(slog.NewJSONHandler(f, &slog.HandlerOptions{
+		Level: slog.LevelDebug,
+	}))
+	return logger, f
+}
+
+// diffTest is a test helper, testing got against contents of a goldenFile.
+func diffTest(t *testing.T, tempFile, goldenFile string) {
+	rawGot, err := os.ReadFile(tempFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Helper()
+	if *updateGolden {
+		got := removeLogVariance(t, rawGot)
+		if err := os.WriteFile(filepath.Join("testdata", goldenFile), got, os.ModePerm); err != nil {
+			t.Fatal(err)
+		}
+		return
+	}
+
+	want, err := os.ReadFile(filepath.Join("testdata", goldenFile))
+	if err != nil {
+		t.Fatal(err)
+	}
+	got := removeLogVariance(t, rawGot)
+
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Errorf("mismatch(-want, +got): %s", diff)
+	}
+}
+
+// removeLogVariance removes parts of log lines that may differ between runs
+// and/or machines.
+func removeLogVariance(t *testing.T, in []byte) []byte {
+	if len(in) == 0 {
+		return in
+	}
+	bs := bytes.Split(in, []byte("\n"))
+	for i, b := range bs {
+		if len(b) == 0 {
+			continue
+		}
+		m := map[string]any{}
+		if err := json.Unmarshal(b, &m); err != nil {
+			t.Fatal(err)
+		}
+		delete(m, "time")
+		if sl, ok := m["sourceLocation"].(map[string]any); ok {
+			delete(sl, "file")
+			// So that if test cases move around in this file they don't cause
+			// failures
+			delete(sl, "line")
+		}
+		b2, err := json.Marshal(m)
+		if err != nil {
+			t.Fatal(err)
+		}
+		t.Logf("%s", b2)
+		bs[i] = b2
+	}
+	return bytes.Join(bs, []byte("\n"))
+}

compute/metadata/metadata.go

@@ -418,9 +418,10 @@ type Client struct {
 
 // Options for configuring a [Client].
 type Options struct {
-	// Client is the HTTP used to make requests. Optional.
+	// Client is the HTTP client used to make requests. Optional.
 	Client *http.Client
-	// Logger is used to log information about outgoing requests. Optional.
+	// Logger is used to log information about HTTP request and responses.
+	// If not provided, nothing will be logged. Optional.
 	Logger *slog.Logger
 }
 

compute/metadata/testdata/httpRequest.log

@@ -0,0 +1 @@
+{"level":"DEBUG","msg":"msg","request":{"headers":{"Foo":"bar"},"method":"POST","url":"https://example.com/computeMetadata/v1/instance/service-accounts/default/token"}}

compute/metadata/testdata/httpResponse.log

@@ -0,0 +1 @@
+{"level":"DEBUG","msg":"msg","response":{"headers":{"Foo":"bar"},"payload":{"access_token":"token","expires_in":600,"token_type":"Bearer"},"status":"200"}}