[New go generator] Implement declaring unions.

mojom/generators/go/templates/structs_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 (
+        "testing"
+
+        "mojom/generators/go/translator"
+)
+
+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)
+}
+
+func TestDecodingStructVersions(t *testing.T) {
+        expected := `var someStruct_Versions []bindings.DataHeader = []bindings.DataHeader{
+        bindings.DataHeader{80, 0},
+        bindings.DataHeader{100, 1},
+        bindings.DataHeader{120, 2},
+}`
+
+        type structVersion struct {
+                NumBytes uint32
+                Version  uint32
+        }
+
+        s := struct {
+                PrivateName string
+                Versions    []structVersion
+        }{
+                PrivateName: "someStruct",
+                Versions: []structVersion{
+                        {80, 0},
+                        {100, 1},
+                        {120, 2},
+                },
+        }
+
+        check(t, expected, "StructVersions", s)
+}