firestore: use a separate project for integration tests

Change-Id: Iea02d241a67f77b809b947edca4020ea4157f27b
Reviewed-on: https://code-review.googlesource.com/17410
Reviewed-by: Michael Darakananda <pongad@google.com>

Author: jba

CONTRIBUTING.md

@@ -42,6 +42,12 @@ run the against the actual APIs.
 - **GCLOUD_TESTS_GOLANG_KEY**: The path to the JSON key file.
 - **GCLOUD_TESTS_API_KEY**: Your API key.
 
+Firestore requires a different project and key:
+
+- **GCLOUD_TESTS_GOLANG_FIRESTORE_PROJECT_ID**: Developers Console project's ID
+  supporting Firestore
+- **GCLOUD_TESTS_GOLANG_FIRESTORE_KEY**: The path to the JSON key file.
+
 Install the [gcloud command-line tool][gcloudcli] to your machine and use it
 to create some resources used in integration tests.
 

firestore/integration_test.go

@@ -42,6 +42,11 @@ func TestMain(m *testing.M) {
 	os.Exit(status)
 }
 
+const (
+	envProjID     = "GCLOUD_TESTS_GOLANG_FIRESTORE_PROJECT_ID"
+	envPrivateKey = "GCLOUD_TESTS_GOLANG_FIRESTORE_KEY"
+)
+
 var (
 	iClient       *Client
 	iColl         *CollectionRef
@@ -54,12 +59,13 @@ func initIntegrationTest() {
 		return
 	}
 	ctx := context.Background()
-	testProjectID := testutil.ProjID()
+	testProjectID := os.Getenv(envProjID)
 	if testProjectID == "" {
 		log.Println("Integration tests skipped. See CONTRIBUTING.md for details")
 		return
 	}
-	ts := testutil.TokenSource(ctx, "https://www.googleapis.com/auth/cloud-platform",
+	ts := testutil.TokenSourceEnv(ctx, envPrivateKey,
+		"https://www.googleapis.com/auth/cloud-platform",
 		"https://www.googleapis.com/auth/datastore")
 	if ts == nil {
 		log.Fatal("The project key must be set. See CONTRIBUTING.md for details")
@@ -551,9 +557,9 @@ func TestIntegration_ServerTimestamp(t *testing.T) {
 	ctx := context.Background()
 	doc := integrationColl(t).NewDoc()
 	// Bound times of the RPC, with some slack for clock skew.
-	start := time.Now().Add(-50 * time.Millisecond)
+	start := time.Now()
 	mustCreate("ServerTimestamp", t, doc, data)
-	end := time.Now().Add(50 * time.Millisecond)
+	end := time.Now()
 	ds, err := doc.Get(ctx)
 	if err != nil {
 		t.Fatal(err)

internal/testutil/context.go

@@ -33,20 +33,24 @@ const (
 // ProjID returns the project ID to use in integration tests, or the empty
 // string if none is configured.
 func ProjID() string {
-	projID := os.Getenv(envProjID)
-	if projID == "" {
-		return ""
-	}
-	return projID
+	return os.Getenv(envProjID)
 }
 
 // TokenSource returns the OAuth2 token source to use in integration tests,
-// or nil if none is configured. If the environment variable is unset,
-// TokenSource will try to find 'Application Default Credentials'. Else,
-// TokenSource will return nil.
-// TokenSource will log.Fatal if the token source is specified but missing or invalid.
+// or nil if none is configured. It uses the standard environment variable
+// for tests in this repo.
 func TokenSource(ctx context.Context, scopes ...string) oauth2.TokenSource {
-	key := os.Getenv(envPrivateKey)
+	return TokenSourceEnv(ctx, envPrivateKey, scopes...)
+}
+
+// TokenSourceEnv returns the OAuth2 token source to use in integration tests. or nil
+// if none is configured. It tries to get credentials from the filename in the
+// environment variable envVar. If the environment variable is unset, TokenSourceEnv
+// will try to find 'Application Default Credentials'. Else, TokenSourceEnv will
+// return nil. TokenSourceEnv will log.Fatal if the token source is specified but
+// missing or invalid.
+func TokenSourceEnv(ctx context.Context, envVar string, scopes ...string) oauth2.TokenSource {
+	key := os.Getenv(envVar)
 	if key == "" { // Try for application default credentials.
 		ts, err := google.DefaultTokenSource(ctx, scopes...)
 		if err != nil {