[ios] Refactor SessionServiceIOS to remove dependency on BrowserState.

ios/chrome/browser/sessions/session_service_ios_unittest.mm

Index: ios/chrome/browser/sessions/session_service_ios_unittest.mm
diff --git a/ios/chrome/browser/sessions/session_service_ios_unittest.mm b/ios/chrome/browser/sessions/session_service_ios_unittest.mm
index 41ec9cda9176d6563cc51a01e773ef65c688aa60..67cc88bfff2f9f27193f06be14689987883b9643 100644
--- a/ios/chrome/browser/sessions/session_service_ios_unittest.mm
+++ b/ios/chrome/browser/sessions/session_service_ios_unittest.mm
@@ -11,17 +11,14 @@
 #include "base/files/scoped_temp_dir.h"
 #include "base/path_service.h"
 #include "base/strings/sys_string_conversions.h"
-#include "ios/chrome/browser/browser_state/test_chrome_browser_state.h"
+#include "base/test/scoped_task_environment.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "ios/chrome/browser/chrome_paths.h"
 #import "ios/chrome/browser/sessions/session_service_ios.h"
 #import "ios/chrome/browser/sessions/session_window_ios.h"
-#include "ios/web/public/navigation_item.h"
-#import "ios/web/public/navigation_manager.h"
-#include "ios/web/public/test/test_web_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/gtest_mac.h"
 #include "testing/platform_test.h"
-#import "third_party/ocmock/OCMock/OCMock.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -38,123 +35,135 @@ class SessionServiceTest : public PlatformTest {
  protected:
   void SetUp() override {
     PlatformTest::SetUp();
-    ASSERT_TRUE(test_dir_.CreateUniqueTempDir());
-    TestChromeBrowserState::Builder test_cbs_builder;
-    test_cbs_builder.SetPath(test_dir_.GetPath());
-    chrome_browser_state_ = test_cbs_builder.Build();
-    directory_name_ = [base::SysUTF8ToNSString(
-        chrome_browser_state_->GetStatePath().value()) copy];
+    ASSERT_TRUE(scoped_temp_directory_.CreateUniqueTempDir());
+    base::FilePath directory_name = scoped_temp_directory_.GetPath();
+    directory_name = directory_name.Append(FILE_PATH_LITERAL("sessions"));
+    directory_name_ = base::SysUTF8ToNSString(directory_name.AsUTF8Unsafe());
+
+    scoped_refptr<base::SequencedTaskRunner> task_runner =
+        base::ThreadTaskRunnerHandle::Get();
+    session_service_ =
+        [[SessionServiceIOS alloc] initWithTaskRunner:task_runner];
   }
 
-  // Helper function to load a SessionWindowIOS from a given testdata
-  // |filename|.  Returns nil if there was an error loading the session.
-  SessionWindowIOS* LoadSessionFromTestDataFile(
-      const base::FilePath::StringType& filename) {
-    SessionServiceIOS* service = [SessionServiceIOS sharedService];
-    base::FilePath plist_path;
-    bool success = PathService::Get(ios::DIR_TEST_DATA, &plist_path);
-    EXPECT_TRUE(success);
-    if (!success) {
+  void TearDown() override { session_service_ = nil; }
+
+  // Returns the path to serialized SessionWindowIOS from a testdata file named
+  // |filename| or nil if the file cannot be found.
+  NSString* SessionPathForTestData(const base::FilePath::CharType* filename) {
+    base::FilePath session_path;
+    if (!PathService::Get(ios::DIR_TEST_DATA, &session_path))
       return nil;
-    }
 
-    plist_path = plist_path.AppendASCII("sessions");
-    plist_path = plist_path.Append(filename);
-    EXPECT_TRUE(base::PathExists(plist_path));
+    session_path = session_path.Append(FILE_PATH_LITERAL("sessions"));
+    session_path = session_path.Append(filename);
+    if (!base::PathExists(session_path))
+      return nil;
 
-    NSString* path = base::SysUTF8ToNSString(plist_path.value());
-    return [service loadWindowFromPath:path];
+    return base::SysUTF8ToNSString(session_path.AsUTF8Unsafe());
   }
 
-  ios::ChromeBrowserState* chrome_browser_state() {
-    return chrome_browser_state_.get();
+  NSData* CreateSerializedSessionWindow() {
+    SessionWindowIOS* session_window =
+        [[SessionWindowIOS alloc] initWithSessions:@[]
+                                     selectedIndex:NSNotFound];
+    return [NSKeyedArchiver archivedDataWithRootObject:session_window];
   }
 
+  SessionServiceIOS* session_service() { return session_service_; }
+
   NSString* directory_name() { return directory_name_; }
 
+  NSString* session_path() {
+    return [session_service() sessionPathForDirectory:directory_name()];
+  }
+
  private:
-  base::ScopedTempDir test_dir_;
-  web::TestWebThreadBundle thread_bundle_;
-  std::unique_ptr<ios::ChromeBrowserState> chrome_browser_state_;
+  base::ScopedTempDir scoped_temp_directory_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
+  SessionServiceIOS* session_service_;
   NSString* directory_name_;
 
   DISALLOW_COPY_AND_ASSIGN(SessionServiceTest);
 };
 
-TEST_F(SessionServiceTest, Singleton) {

[sdefresne, 2017/04/10 14:37:18]

I removed this test intentionally as the singleton accessor does initialise the
SessionServiceIOS task runner from WebThread, but the test was using
web::TestWebThreadBundle, thus the singleton was referencing a TaskRunner that
was completely disconnected from everything.

In general it is incorrect for unit tests to use singletons.

-  SessionServiceIOS* service = [SessionServiceIOS sharedService];
-  EXPECT_TRUE(service != nil);
-
-  SessionServiceIOS* another_service = [SessionServiceIOS sharedService];
-  EXPECT_TRUE(another_service != nil);
-
-  EXPECT_TRUE(service == another_service);
-}
-
 TEST_F(SessionServiceTest, SaveWindowToDirectory) {
-  id session_window_mock =
-      [OCMockObject niceMockForClass:[SessionWindowIOS class]];
-  SessionServiceIOS* service = [SessionServiceIOS sharedService];
-  [service performSaveWindow:session_window_mock toDirectory:directory_name()];
+  NSData* session_data = CreateSerializedSessionWindow();
+  ASSERT_NSNE(nil, session_data);
+
+  [session_service() performSaveSessionData:session_data
+                                sessionPath:session_path()];
 
   NSFileManager* file_manager = [NSFileManager defaultManager];
   EXPECT_TRUE([file_manager removeItemAtPath:directory_name() error:nullptr]);
 }
 
 TEST_F(SessionServiceTest, SaveWindowToDirectoryAlreadyExistent) {
-  id session_window_mock =
-      [OCMockObject niceMockForClass:[SessionWindowIOS class]];
-  EXPECT_TRUE([[NSFileManager defaultManager]
+  ASSERT_TRUE([[NSFileManager defaultManager]
             createDirectoryAtPath:directory_name()
       withIntermediateDirectories:YES
                        attributes:nil
                             error:nullptr]);
 
-  SessionServiceIOS* service = [SessionServiceIOS sharedService];
-  [service performSaveWindow:session_window_mock toDirectory:directory_name()];
+  NSData* session_data = CreateSerializedSessionWindow();
+  ASSERT_NSNE(nil, session_data);
+
+  [session_service() performSaveSessionData:session_data
+                                sessionPath:session_path()];
 
   NSFileManager* file_manager = [NSFileManager defaultManager];
   EXPECT_TRUE([file_manager removeItemAtPath:directory_name() error:nullptr]);
 }
 
 TEST_F(SessionServiceTest, LoadEmptyWindowFromDirectory) {
-  SessionServiceIOS* service = [SessionServiceIOS sharedService];
+  SessionServiceIOS* service = session_service();
   SessionWindowIOS* session_window =
-      [service loadWindowForBrowserState:chrome_browser_state()];
+      [service loadSessionWindowFromPath:session_path()];
   EXPECT_TRUE(session_window == nil);
 }
 
 TEST_F(SessionServiceTest, LoadWindowFromDirectory) {
-  SessionServiceIOS* service = [SessionServiceIOS sharedService];
-  SessionWindowIOS* origSessionWindow = [[SessionWindowIOS alloc] init];
-  [service performSaveWindow:origSessionWindow toDirectory:directory_name()];
+  NSData* session_data = CreateSerializedSessionWindow();
+  ASSERT_NSNE(nil, session_data);
+
+  [session_service() performSaveSessionData:session_data
+                                sessionPath:session_path()];
 
   SessionWindowIOS* session_window =
-      [service loadWindowForBrowserState:chrome_browser_state()];
+      [session_service() loadSessionWindowFromPath:session_path()];
   EXPECT_TRUE(session_window != nil);
   EXPECT_EQ(NSNotFound, static_cast<NSInteger>(session_window.selectedIndex));
   EXPECT_EQ(0U, session_window.sessions.count);
 }
 
 TEST_F(SessionServiceTest, LoadCorruptedWindow) {
+  NSString* session_path =
+      SessionPathForTestData(FILE_PATH_LITERAL("corrupted.plist"));
+  ASSERT_NSNE(nil, session_path);
   SessionWindowIOS* session_window =
-      LoadSessionFromTestDataFile(FILE_PATH_LITERAL("corrupted.plist"));
+      [session_service() loadSessionWindowFromPath:session_path];
   EXPECT_TRUE(session_window == nil);
 }
 
 // TODO(crbug.com/661633): remove this once M67 has shipped (i.e. once more
 // than a year has passed since the introduction of the compatibility code).
 TEST_F(SessionServiceTest, LoadM57Session) {
+  NSString* session_path =
+      SessionPathForTestData(FILE_PATH_LITERAL("session_m57.plist"));
+  ASSERT_NSNE(nil, session_path);
   SessionWindowIOS* session_window =
-      LoadSessionFromTestDataFile(FILE_PATH_LITERAL("session_m57.plist"));
+      [session_service() loadSessionWindowFromPath:session_path];
   EXPECT_TRUE(session_window != nil);
 }
 
 // TODO(crbug.com/661633): remove this once M68 has shipped (i.e. once more
 // than a year has passed since the introduction of the compatibility code).
 TEST_F(SessionServiceTest, LoadM58Session) {
+  NSString* session_path =
+      SessionPathForTestData(FILE_PATH_LITERAL("session_m58.plist"));
+  ASSERT_NSNE(nil, session_path);
   SessionWindowIOS* session_window =
-      LoadSessionFromTestDataFile(FILE_PATH_LITERAL("session_m58.plist"));
+      [session_service() loadSessionWindowFromPath:session_path];
   EXPECT_TRUE(session_window != nil);
 }