spanner: check database name and add a trace span even when using the…

… emulator

These are sensible to use even for use with an emulator.

Updates #1181.

Change-Id: I5664f98ca2a700abe976cbbd587e8f2ee291d01b
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/43232
Reviewed-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jean de Klerk <deklerk@google.com>

spanner/client.go

@@ -149,15 +149,15 @@ func NewClientWithConfig(ctx context.Context, database string, config ClientConf
 		config.MaxBurst = 10
 	}
 
-	if emulatorAddr := os.Getenv("SPANNER_EMULATOR_HOST"); emulatorAddr == "" {
-		// Validate database path.
-		if err := validDatabaseName(database); err != nil {
-			return nil, err
-		}
+	// Validate database path.
+	if err := validDatabaseName(database); err != nil {
+		return nil, err
+	}
 
-		ctx = trace.StartSpan(ctx, "cloud.google.com/go/spanner.NewClient")
-		defer func() { trace.EndSpan(ctx, err) }()
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/spanner.NewClient")
+	defer func() { trace.EndSpan(ctx, err) }()
 
+	if emulatorAddr := os.Getenv("SPANNER_EMULATOR_HOST"); emulatorAddr == "" {
 		// gRPC options.
 		allOpts := []option.ClientOption{
 			option.WithEndpoint(endpoint),

spanner/client_test.go

@@ -424,7 +424,7 @@ func TestNewClient_ConnectToEmulator(t *testing.T) {
 	os.Setenv("SPANNER_EMULATOR_HOST", s.Addr())
 	defer os.Setenv("SPANNER_EMULATOR_HOST", oldEnv)
 
-	c, err := NewClient(ctx, "some-db")
+	c, err := NewClient(ctx, "projects/some-proj/instances/some-inst/databases/some-db")
 	if err != nil {
 		t.Fatal(err)
 	}