[New go generator] Implement declaring unions.

mojom/generators/go/templates/declarations_test.go

-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package templates
-
-import (
-        "bytes"
-        "fmt"
-        "strings"
-        "testing"
-
-        "mojom/generators/go/gofmt"
-        "mojom/generators/go/translator"
-)
-
-func check(t *testing.T, expected string, template string, input interface{}) {
-        buffer := &bytes.Buffer{}
-        if err := goFileTmpl.ExecuteTemplate(buffer, template, input); err != nil {
-                panic(err)
-        }
-
-        src := buffer.String()
-        actual, err := gofmt.FormatFragment(src)
-        if err != nil {
-                t.Fatalf("Formatting failed: %s\n%s\n", err, src)
-        }
-
-        if expected != actual {
-                errorMsg := fmt.Sprintf("Failed check: Expected\n%s\nActual\n%s\n", expected, actual)
-                if strings.TrimSpace(expected) == strings.TrimSpace(actual) {
-                        errorMsg = fmt.Sprintf("%s\nTrailing or leading spaces differ.\n", errorMsg)
-                }
-                t.Fatalf(errorMsg)
-        }
-}
-
-func TestStructDecl(t *testing.T) {
-        expected := `type Foo struct {
-        Alpha string
-        Beta  uint32
-}`
-
-        s := translator.StructTemplate{
-                Name: "Foo",
-                Fields: []translator.StructFieldTemplate{
-                        {Name: "Alpha", Type: "string"},
-                        {Name: "Beta", Type: "uint32"},
-                },
-        }
-
-        check(t, expected, "StructDecl", s)
-}