Add unittests for chromecast/base/error_codes.h.

Also fixes bug resulting from const& to temporary object in
chromecast/base/error_codes.cc.

BUG= b/22201989

Review URL: https://codereview.chromium.org/1214263003

Cr-Commit-Position: refs/heads/master@{#336880}

4 files changed, 68 insertions, 1 deletions

diff --git a/chromecast/base/BUILD.gn b/chromecast/base/BUILD.gn
index 09ad4ce..549fee2 100644
--- a/chromecast/base/BUILD.gn
+++ b/chromecast/base/BUILD.gn
@@ -35,6 +35,7 @@ source_set("base") {
 
 test("cast_base_unittests") {
   sources = [
+    "error_codes_unittest.cc",
     "path_utils_unittest.cc",
     "process_utils_unittest.cc",
     "serializers_unittest.cc",
diff --git a/chromecast/base/error_codes.cc b/chromecast/base/error_codes.cc
index 7cd3551..e26a820 100644
--- a/chromecast/base/error_codes.cc
+++ b/chromecast/base/error_codes.cc
@@ -47,7 +47,7 @@ ErrorCode GetInitialErrorCode() {
 bool SetInitialErrorCode(ErrorCode initial_error_code) {
   // Note: Do not use Chromium IO methods in this function. When cast_shell
   // crashes, this function can be called by any thread.
-  const std::string& error_file_path = GetInitialErrorFilePath().value();
+  const std::string error_file_path = GetInitialErrorFilePath().value();
 
   if (initial_error_code > NO_ERROR && initial_error_code <= ERROR_UNKNOWN) {
     const std::string initial_error_code_str(
diff --git a/chromecast/base/error_codes_unittest.cc b/chromecast/base/error_codes_unittest.cc
new file mode 100644
index 0000000..293d895
--- /dev/null
+++ b/chromecast/base/error_codes_unittest.cc
@@ -0,0 +1,65 @@
+// Copyright 2015 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.
+
+#include "base/base_paths.h"
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/test/scoped_path_override.h"
+#include "chromecast/base/error_codes.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chromecast {
+
+class ErrorCodesTest : public testing::Test {
+ protected:
+  ErrorCodesTest() {}
+  ~ErrorCodesTest() override {}
+
+  void SetUp() override {
+    // Set up a temporary directory which will be used as our fake home dir.
+    ASSERT_TRUE(base::CreateNewTempDirectory("", &fake_home_dir_));
+    path_override_.reset(
+        new base::ScopedPathOverride(base::DIR_HOME, fake_home_dir_));
+  }
+
+  base::FilePath fake_home_dir_;
+  scoped_ptr<base::ScopedPathOverride> path_override_;
+};
+
+TEST_F(ErrorCodesTest, GetInitialErrorCodeReturnsNoErrorIfMissingFile) {
+  EXPECT_EQ(NO_ERROR, GetInitialErrorCode());
+}
+
+TEST_F(ErrorCodesTest, SetInitialErrorCodeSucceedsWithNoError) {
+  ASSERT_TRUE(SetInitialErrorCode(NO_ERROR));
+
+  // File should not be written.
+  ASSERT_FALSE(base::PathExists(fake_home_dir_.Append("initial_error")));
+  EXPECT_EQ(NO_ERROR, GetInitialErrorCode());
+}
+
+TEST_F(ErrorCodesTest, SetInitialErrorCodeSucceedsWithValidErrors) {
+  // Write initial error and read it from the file.
+  EXPECT_TRUE(SetInitialErrorCode(ERROR_WEB_CONTENT_RENDER_VIEW_GONE));
+  EXPECT_TRUE(base::PathExists(fake_home_dir_.Append("initial_error")));
+  EXPECT_EQ(ERROR_WEB_CONTENT_RENDER_VIEW_GONE, GetInitialErrorCode());
+
+  // File should be updated with most recent error.
+  EXPECT_TRUE(SetInitialErrorCode(ERROR_UNKNOWN));
+  EXPECT_TRUE(base::PathExists(fake_home_dir_.Append("initial_error")));
+  EXPECT_EQ(ERROR_UNKNOWN, GetInitialErrorCode());
+
+  // File should be updated with most recent error.
+  EXPECT_TRUE(SetInitialErrorCode(ERROR_WEB_CONTENT_NAME_NOT_RESOLVED));
+  EXPECT_TRUE(base::PathExists(fake_home_dir_.Append("initial_error")));
+  EXPECT_EQ(ERROR_WEB_CONTENT_NAME_NOT_RESOLVED, GetInitialErrorCode());
+
+  // File should be removed after writing NO_ERROR.
+  EXPECT_TRUE(SetInitialErrorCode(NO_ERROR));
+  EXPECT_FALSE(base::PathExists(fake_home_dir_.Append("initial_error")));
+  EXPECT_EQ(NO_ERROR, GetInitialErrorCode());
+}
+
+}  // namespace chromecast
diff --git a/chromecast/chromecast_tests.gypi b/chromecast/chromecast_tests.gypi
index 6f79b0f..2df61ab0 100644
--- a/chromecast/chromecast_tests.gypi
+++ b/chromecast/chromecast_tests.gypi
@@ -16,6 +16,7 @@
         '../testing/gtest.gyp:gtest',
       ],
       'sources': [
+        'base/error_codes_unittest.cc',
         'base/path_utils_unittest.cc',
         'base/process_utils_unittest.cc',
         'base/serializers_unittest.cc',