Add test coverage

builder/googlecompute/config_test.go

@@ -305,7 +305,11 @@ func testConfig(t *testing.T) map[string]interface{} {
 		"source_image": "foo",
 		"ssh_username": "root",
 		"image_family": "bar",
-		"zone":         "us-east1-a",
+		"image_labels": string{
+			"label-1": "value-1",
+			"label-2": "value-2",
+		},
+		"zone": "us-east1-a",
 	}
 }
 

builder/googlecompute/step_create_image_test.go

@@ -46,6 +46,7 @@ func TestStepCreateImage(t *testing.T) {
 	assert.Equal(t, d.CreateImageFamily, c.ImageFamily, "Incorrect image family passed to driver.")
 	assert.Equal(t, d.CreateImageZone, c.Zone, "Incorrect image zone passed to driver.")
 	assert.Equal(t, d.CreateImageDisk, c.DiskName, "Incorrect disk passed to driver.")
+	assert.Equal(t, d.CreateImageLabels, c.ImageLabels, "Incorrect image_labels passed to driver.")
 }
 
 func TestStepCreateImage_errorOnChannel(t *testing.T) {