Skip test if SPANNER_DATABASE isn’t set

Author: christianklotz

database/spanner/README.md

@@ -26,4 +26,10 @@ See [Google Spanner Documentation](https://cloud.google.com/spanner/docs) for de
 > 1481574547/u create_users_table (21.354507597s)
 > 1496539702/u add_city_to_users (41.647359754s)
 > 1496601752/u add_index_on_user_emails (2m12.155787369s)
-> 1496602638/u create_books_table (2m30.77299181s)
+> 1496602638/u create_books_table (2m30.77299181s)
+
+## Testing
+
+To unit test the `spanner` driver, `SPANNER_DATABASE` needs to be set. You'll
+need to sign-up to Google Cloud Platform (GCP) and have a running Spanner
+instance since it is not possible to run Google Spanner outside GCP.

database/spanner/spanner_test.go

@@ -10,10 +10,14 @@ import (
 
 func Test(t *testing.T) {
 	if testing.Short() {
-		t.Skip("skipping testing Google Spanner during short testing")
+		t.Skip("skipping test in short mode.")
+	}
+
+	db, ok := os.LookupEnv("SPANNER_DATABASE")
+	if !ok {
+		t.Skip("SPANNER_DATABASE not set, skipping test.")
 	}
 
-	db := os.Getenv("SPANNER_DATABASE")
 	s := &Spanner{}
 	addr := fmt.Sprintf("spanner://%v", db)
 	d, err := s.Open(addr)