Function TestSimpleMigrationForward

errbase/migrations_test.go:31–60

Scenario 1: simple migration, forward direction - v2 renames foo -> bar - v2 and v1 are connected - v1 sends an error to v2.

(t *testing.T)

// - v2 and v1 are connected
// - v1 sends an error to v2.
func TestSimpleMigrationForward(t *testing.T) {
	defer errbase.TestingWithEmptyMigrationRegistry()()

	// == Scenario on v1 ==
	origErr := fooErr{}
	errbase.RegisterLeafDecoder(errbase.GetTypeKey(origErr),
		func(_ context.Context, _ string, _ []string, _ proto.Message) error { return fooErr{} })

	// Send the error to v2.
	enc := errbase.EncodeError(context.Background(), origErr)
	// Clean up, so that type foo becomes unknown.
	errbase.RegisterLeafDecoder(errbase.GetTypeKey(origErr), nil)

	// == Scenario on v2 ==
	// Register the fact that foo was migrated to bar.
	errbase.RegisterTypeMigration(myPkgPath, "errbase_test.fooErr", barErr{})
	// Register the bar decoder.
	errbase.RegisterLeafDecoder(errbase.GetTypeKey(barErr{}),
		func(_ context.Context, _ string, _ []string, _ proto.Message) error { return barErr{} })
	// Receive the error from v1.
	dec := errbase.DecodeError(context.Background(), enc)
	// Clean up, so that type bar becomes unknown for further tests.
	errbase.RegisterLeafDecoder(errbase.GetTypeKey(barErr{}), nil)

	// Main test: check that v2 recognized the foo error from
	// v1 and instantiated it as bar.
	if _, ok := dec.(barErr); !ok {
		t.Errorf("migration failed; expected type barErr, got %T", dec)
	}
}

// Scenario 1: simple migration, backward direction
// - v2 renames foo -> bar