Fix Firestore tests for M22 (#834)

* Add FIRFirestoreTests to the Firestore Xcode project

* Avoid waitForExpectations:timeout:

This API was added in Xcode 8.3, but we still build production releases
with Xcode 8.2. waitForExpectationsWithTimeout:handler: is available
from Xcode 7.2.

* Add AppForUnitTesting

Add a utility for constructing a Firebase App for testing.

* Handle the nil UID from FIRAuth

* Avoid running CMake tests twice

* Only build app_testing on Apple platforms

* Revise test.sh messages

15 files changed, 227 insertions, 79 deletions

diff --git a/Firestore/Example/Firestore.xcodeproj/project.pbxproj b/Firestore/Example/Firestore.xcodeproj/project.pbxproj
index 2398caa..6287462 100644
--- a/Firestore/Example/Firestore.xcodeproj/project.pbxproj
+++ b/Firestore/Example/Firestore.xcodeproj/project.pbxproj
@@ -25,6 +25,8 @@
 /* Begin PBXBuildFile section */
 		3B843E4C1F3A182900548890 /* remote_store_spec_test.json in Resources */ = {isa = PBXBuildFile; fileRef = 3B843E4A1F3930A400548890 /* remote_store_spec_test.json */; };
 		5436F32420008FAD006E51E3 /* string_printf_test.cc in Sources */ = {isa = PBXBuildFile; fileRef = 5436F32320008FAD006E51E3 /* string_printf_test.cc */; };
+		5467FB01203E5717009C9584 /* FIRFirestoreTests.mm in Sources */ = {isa = PBXBuildFile; fileRef = 5467FAFF203E56F8009C9584 /* FIRFirestoreTests.mm */; };
+		5467FB08203E6A44009C9584 /* app_testing.mm in Sources */ = {isa = PBXBuildFile; fileRef = 5467FB07203E6A44009C9584 /* app_testing.mm */; };
 		54740A571FC914BA00713A1A /* secure_random_test.cc in Sources */ = {isa = PBXBuildFile; fileRef = 54740A531FC913E500713A1A /* secure_random_test.cc */; };
 		54740A581FC914F000713A1A /* autoid_test.cc in Sources */ = {isa = PBXBuildFile; fileRef = 54740A521FC913E500713A1A /* autoid_test.cc */; };
 		54764FAF1FAA21B90085E60A /* FSTGoogleTestTests.mm in Sources */ = {isa = PBXBuildFile; fileRef = 54764FAE1FAA21B90085E60A /* FSTGoogleTestTests.mm */; };
@@ -216,6 +218,9 @@
 		42491D7DC8C8CD245CC22B93 /* Pods-SwiftBuildTest.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-SwiftBuildTest.debug.xcconfig"; path = "Pods/Target Support Files/Pods-SwiftBuildTest/Pods-SwiftBuildTest.debug.xcconfig"; sourceTree = "<group>"; };
 		4EBC5F5ABE1FD097EFE5E224 /* Pods-Firestore_Example.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Firestore_Example.release.xcconfig"; path = "Pods/Target Support Files/Pods-Firestore_Example/Pods-Firestore_Example.release.xcconfig"; sourceTree = "<group>"; };
 		5436F32320008FAD006E51E3 /* string_printf_test.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = string_printf_test.cc; path = ../../core/test/firebase/firestore/util/string_printf_test.cc; sourceTree = "<group>"; };
+		5467FAFF203E56F8009C9584 /* FIRFirestoreTests.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = FIRFirestoreTests.mm; sourceTree = "<group>"; };
+		5467FB06203E6A44009C9584 /* app_testing.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = app_testing.h; path = ../../core/test/firebase/firestore/testutil/app_testing.h; sourceTree = "<group>"; };
+		5467FB07203E6A44009C9584 /* app_testing.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; name = app_testing.mm; path = ../../core/test/firebase/firestore/testutil/app_testing.mm; sourceTree = "<group>"; };
 		54740A521FC913E500713A1A /* autoid_test.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = autoid_test.cc; path = ../../core/test/firebase/firestore/util/autoid_test.cc; sourceTree = "<group>"; };
 		54740A531FC913E500713A1A /* secure_random_test.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = secure_random_test.cc; path = ../../core/test/firebase/firestore/util/secure_random_test.cc; sourceTree = "<group>"; };
 		54764FAE1FAA21B90085E60A /* FSTGoogleTestTests.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; name = FSTGoogleTestTests.mm; path = GoogleTest/FSTGoogleTestTests.mm; sourceTree = "<group>"; };
@@ -429,6 +434,15 @@
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
+		5467FB05203E652F009C9584 /* testutil */ = {
+			isa = PBXGroup;
+			children = (
+				5467FB06203E6A44009C9584 /* app_testing.h */,
+				5467FB07203E6A44009C9584 /* app_testing.mm */,
+			);
+			name = testutil;
+			sourceTree = "<group>";
+		};
 		54740A561FC913EB00713A1A /* util */ = {
 			isa = PBXGroup;
 			children = (
@@ -452,6 +466,7 @@
 				AB380CF7201937B800D97691 /* core */,
 				54EB764B202277970088B8F3 /* immutable */,
 				AB356EF5200E9D1A0089B766 /* model */,
+				5467FB05203E652F009C9584 /* testutil */,
 				54740A561FC913EB00713A1A /* util */,
 				54764FAE1FAA21B90085E60A /* FSTGoogleTestTests.mm */,
 				AB7BAB332012B519001E0872 /* geo_point_test.cc */,
@@ -697,16 +712,17 @@
 		DE51B1831F0D48AC0013853F /* API */ = {
 			isa = PBXGroup;
 			children = (
-				B65D34A7203C99090076A5E1 /* FIRTimestampTest.m */,
 				5492E045202154AA00B64F25 /* FIRCollectionReferenceTests.mm */,
 				5492E049202154AA00B64F25 /* FIRDocumentReferenceTests.mm */,
 				5492E04B202154AA00B64F25 /* FIRDocumentSnapshotTests.mm */,
 				5492E04C202154AA00B64F25 /* FIRFieldPathTests.mm */,
 				5492E04A202154AA00B64F25 /* FIRFieldValueTests.mm */,
+				5467FAFF203E56F8009C9584 /* FIRFirestoreTests.mm */,
 				5492E048202154AA00B64F25 /* FIRGeoPointTests.mm */,
 				5492E04F202154AA00B64F25 /* FIRQuerySnapshotTests.mm */,
 				5492E046202154AA00B64F25 /* FIRQueryTests.mm */,
 				5492E04D202154AA00B64F25 /* FIRSnapshotMetadataTests.mm */,
+				B65D34A7203C99090076A5E1 /* FIRTimestampTest.m */,
 				5492E047202154AA00B64F25 /* FSTAPIHelpers.h */,
 				5492E04E202154AA00B64F25 /* FSTAPIHelpers.mm */,
 			);
@@ -1301,6 +1317,7 @@
 				54740A581FC914F000713A1A /* autoid_test.cc in Sources */,
 				548DB927200D590300E00ABC /* assert_test.cc in Sources */,
 				5492E0A62021552D00B64F25 /* FSTPersistenceTestHelpers.mm in Sources */,
+				5467FB01203E5717009C9584 /* FIRFirestoreTests.mm in Sources */,
 				5492E0A12021552D00B64F25 /* FSTMemoryLocalStoreTests.mm in Sources */,
 				5436F32420008FAD006E51E3 /* string_printf_test.cc in Sources */,
 				5492E067202154B900B64F25 /* FSTEventManagerTests.mm in Sources */,
@@ -1334,6 +1351,7 @@
 				5492E065202154B900B64F25 /* FSTViewTests.mm in Sources */,
 				5492E03C2021401F00B64F25 /* XCTestCase+Await.mm in Sources */,
 				B6152AD7202A53CB000E5744 /* document_key_test.cc in Sources */,
+				5467FB08203E6A44009C9584 /* app_testing.mm in Sources */,
 				54764FAF1FAA21B90085E60A /* FSTGoogleTestTests.mm in Sources */,
 				AB380D04201BC6E400D97691 /* ordered_code_test.cc in Sources */,
 				5492E03F2021401F00B64F25 /* FSTHelpers.mm in Sources */,
diff --git a/Firestore/Example/Firestore.xcodeproj/xcshareddata/xcschemes/Firestore_Tests.xcscheme b/Firestore/Example/Firestore.xcodeproj/xcshareddata/xcschemes/Firestore_Tests.xcscheme
index 920e1f3..846b772 100644
--- a/Firestore/Example/Firestore.xcodeproj/xcshareddata/xcschemes/Firestore_Tests.xcscheme
+++ b/Firestore/Example/Firestore.xcodeproj/xcshareddata/xcschemes/Firestore_Tests.xcscheme
@@ -7,8 +7,11 @@
       buildImplicitDependencies = "YES">
       <BuildActionEntries>
          <BuildActionEntry
+            buildForTesting = "YES"
             buildForRunning = "YES"
-            buildForTesting = "YES">
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
             <BuildableReference
                BuildableIdentifier = "primary"
                BlueprintIdentifier = "6003F5AD195388D20070C39A"
@@ -51,6 +54,15 @@
       debugDocumentVersioning = "YES"
       debugServiceExtension = "internal"
       allowLocationSimulation = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "6003F5AD195388D20070C39A"
+            BuildableName = "Firestore_Tests.xctest"
+            BlueprintName = "Firestore_Tests"
+            ReferencedContainer = "container:Firestore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
       <AdditionalOptions>
       </AdditionalOptions>
    </LaunchAction>
diff --git a/Firestore/Example/Tests/API/FIRFirestoreTests.mm b/Firestore/Example/Tests/API/FIRFirestoreTests.mm
index 4daf35a..7cb49b7 100644
--- a/Firestore/Example/Tests/API/FIRFirestoreTests.mm
+++ b/Firestore/Example/Tests/API/FIRFirestoreTests.mm
@@ -20,21 +20,21 @@
 
 #import <XCTest/XCTest.h>
 
+#include "Firestore/core/test/firebase/firestore/testutil/app_testing.h"
+
+namespace testutil = firebase::firestore::testutil;
+
 @interface FIRFirestoreTests : XCTestCase
 @end
 
 @implementation FIRFirestoreTests
 
 - (void)testDeleteApp {
-  // Create a FIRApp for testing.
-  NSString *appName = @"custom_app_name";
-  FIROptions *options =
-      [[FIROptions alloc] initWithGoogleAppID:@"1:123:ios:123ab" GCMSenderID:@"gcm_sender_id"];
-  options.projectID = @"project_id";
-  [FIRApp configureWithName:appName options:options];
-
   // Ensure the app is set appropriately.
-  FIRApp *app = [FIRApp appNamed:appName];
+  FIRApp *app = testutil::AppForUnitTesting();
+  NSString *appName = app.name;
+  FIROptions *options = app.options;
+
   FIRFirestore *firestore = [FIRFirestore firestoreForApp:app];
   XCTAssertEqualObjects(firestore.app, app);
 
@@ -56,7 +56,10 @@
     [defaultAppDeletedExpectation fulfill];
   }];
 
-  [self waitForExpectations:@[ defaultAppDeletedExpectation ] timeout:2];
+  [self waitForExpectationsWithTimeout:2
+                               handler:^(NSError *_Nullable error) {
+                                 XCTAssertNil(error);
+                               }];
 }
 
 @end
diff --git a/Firestore/Example/Tests/SpecTests/FSTSpecTests.mm b/Firestore/Example/Tests/SpecTests/FSTSpecTests.mm
index 87e3213..43b2a5f 100644
--- a/Firestore/Example/Tests/SpecTests/FSTSpecTests.mm
+++ b/Firestore/Example/Tests/SpecTests/FSTSpecTests.mm
@@ -332,12 +332,10 @@ static NSString *const kNoIOSTag = @"no-ios";
 }
 
 - (void)doChangeUser:(id)UID {
-  if (UID == nil || [UID isEqual:[NSNull null]]) {
-    [self.driver changeUser:User::Unauthenticated()];
-  } else {
-    XCTAssert([UID isKindOfClass:[NSString class]]);
-    [self.driver changeUser:User(UID)];
+  if ([UID isEqual:[NSNull null]]) {
+    UID = nil;
   }
+  [self.driver changeUser:User::FromUid(UID)];
 }
 
 - (void)doRestart {
diff --git a/Firestore/Source/Auth/FSTCredentialsProvider.mm b/Firestore/Source/Auth/FSTCredentialsProvider.mm
index c3fbeb0..e0dc8aa 100644
--- a/Firestore/Source/Auth/FSTCredentialsProvider.mm
+++ b/Firestore/Source/Auth/FSTCredentialsProvider.mm
@@ -62,7 +62,7 @@ NS_ASSUME_NONNULL_BEGIN
   self = [super init];
   if (self) {
     _app = app;
-    _currentUser = User([self.app getUID]);
+    _currentUser = User::FromUid([self.app getUID]);
     _userCounter = 0;
 
     // Register for user changes so that we can internally track the current user.
@@ -84,8 +84,8 @@ NS_ASSUME_NONNULL_BEGIN
                         return;
                       }
 
-                      NSString *userID = userInfo[FIRAuthStateDidChangeInternalNotificationUIDKey];
-                      User newUser = User(userID);
+                      NSString *uid = userInfo[FIRAuthStateDidChangeInternalNotificationUIDKey];
+                      User newUser = User::FromUid(uid);
                       if (newUser != self->_currentUser) {
                         self->_currentUser = newUser;
                         self.userCounter++;
diff --git a/Firestore/core/CMakeLists.txt b/Firestore/core/CMakeLists.txt
index e70647d..5bf8c5e 100644
--- a/Firestore/core/CMakeLists.txt
+++ b/Firestore/core/CMakeLists.txt
@@ -20,6 +20,7 @@ add_subdirectory(src/firebase/firestore/model)
 add_subdirectory(src/firebase/firestore/remote)
 add_subdirectory(src/firebase/firestore/util)
 
+add_subdirectory(test/firebase/firestore/testutil)
 add_subdirectory(test/firebase/firestore)
 add_subdirectory(test/firebase/firestore/auth)
 add_subdirectory(test/firebase/firestore/core)
diff --git a/Firestore/core/src/firebase/firestore/auth/firebase_credentials_provider_apple.h b/Firestore/core/src/firebase/firestore/auth/firebase_credentials_provider_apple.h
index 65c4c65..66c3c87 100644
--- a/Firestore/core/src/firebase/firestore/auth/firebase_credentials_provider_apple.h
+++ b/Firestore/core/src/firebase/firestore/auth/firebase_credentials_provider_apple.h
@@ -26,6 +26,7 @@
 
 #include <memory>
 #include <mutex>  // NOLINT(build/c++11)
+#include <utility>
 
 #include "Firestore/core/src/firebase/firestore/auth/credentials_provider.h"
 #include "Firestore/core/src/firebase/firestore/auth/user.h"
@@ -76,8 +77,8 @@ class FirebaseCredentialsProvider : public CredentialsProvider {
    * avoid races between notifications arriving and C++ object destruction.
    */
   struct Contents {
-    Contents(FIRApp* app, const absl::string_view uid)
-        : app(app), current_user(uid), mutex() {
+    Contents(FIRApp* app, User&& user)
+        : app(app), current_user(std::move(user)), mutex() {
     }
 
     const FIRApp* app;
diff --git a/Firestore/core/src/firebase/firestore/auth/firebase_credentials_provider_apple.mm b/Firestore/core/src/firebase/firestore/auth/firebase_credentials_provider_apple.mm
index f463958..fe3cb24 100644
--- a/Firestore/core/src/firebase/firestore/auth/firebase_credentials_provider_apple.mm
+++ b/Firestore/core/src/firebase/firestore/auth/firebase_credentials_provider_apple.mm
@@ -28,8 +28,7 @@ namespace firestore {
 namespace auth {
 
 FirebaseCredentialsProvider::FirebaseCredentialsProvider(FIRApp* app)
-    : contents_(
-          std::make_shared<Contents>(app, util::MakeStringView([app getUID]))) {
+    : contents_(std::make_shared<Contents>(app, User::FromUid([app getUID]))) {
   std::weak_ptr<Contents> weak_contents = contents_;
 
   auth_listener_handle_ = [[NSNotificationCenter defaultCenter]
diff --git a/Firestore/core/src/firebase/firestore/auth/user.h b/Firestore/core/src/firebase/firestore/auth/user.h
index cc7b66d..3918c61 100644
--- a/Firestore/core/src/firebase/firestore/auth/user.h
+++ b/Firestore/core/src/firebase/firestore/auth/user.h
@@ -43,12 +43,6 @@ class User {
   /** Construct an authenticated user with the given UID. */
   explicit User(const absl::string_view uid);
 
-#if defined(__OBJC__)
-  explicit User(NSString* uid)
-      : User(firebase::firestore::util::MakeStringView(uid)) {
-  }
-#endif  // defined(__OBJC__)
-
   const std::string& uid() const {
     return uid_;
   }
@@ -62,6 +56,20 @@ class User {
   /** Returns an unauthenticated instance. */
   static const User& Unauthenticated();
 
+#if defined(__OBJC__)
+  /**
+   * Returns an authenticated user if uid is non-nil, otherwise an
+   * unauthenticated user.
+   */
+  static User FromUid(NSString* _Nullable uid) {
+    if (uid == nil) {
+      return Unauthenticated();
+    } else {
+      return User(util::MakeStringView(uid));
+    }
+  }
+#endif  // defined(__OBJC__)
+
   User& operator=(const User& other) = default;
 
   friend bool operator==(const User& lhs, const User& rhs);
diff --git a/Firestore/core/test/firebase/firestore/auth/CMakeLists.txt b/Firestore/core/test/firebase/firestore/auth/CMakeLists.txt
index f470bd7..a6aa2ef 100644
--- a/Firestore/core/test/firebase/firestore/auth/CMakeLists.txt
+++ b/Firestore/core/test/firebase/firestore/auth/CMakeLists.txt
@@ -30,5 +30,6 @@ if(APPLE)
       firebase_credentials_provider_test.mm
     DEPENDS
       firebase_firestore_auth_apple
+      firebase_firestore_testutil
   )
 endif(APPLE)
diff --git a/Firestore/core/test/firebase/firestore/auth/firebase_credentials_provider_test.mm b/Firestore/core/test/firebase/firestore/auth/firebase_credentials_provider_test.mm
index e98d3d8..a6ccc4a 100644
--- a/Firestore/core/test/firebase/firestore/auth/firebase_credentials_provider_test.mm
+++ b/Firestore/core/test/firebase/firestore/auth/firebase_credentials_provider_test.mm
@@ -21,6 +21,7 @@
 #import <FirebaseCore/FIROptionsInternal.h>
 
 #include "Firestore/core/src/firebase/firestore/util/string_apple.h"
+#include "Firestore/core/test/firebase/firestore/testutil/app_testing.h"
 
 #include "gtest/gtest.h"
 
@@ -28,67 +29,51 @@ namespace firebase {
 namespace firestore {
 namespace auth {
 
-// TODO(zxu123): Make this an integration test and get infos from environment.
-// Set a .plist file here to enable the test-case.
-static NSString* const kPlist = @"";
-
-class FirebaseCredentialsProviderTest : public ::testing::Test {
- protected:
-  void SetUp() override {
-    app_ready_ = false;
-    if (![kPlist hasSuffix:@".plist"]) {
-      return;
-    }
-
-    static dispatch_once_t once_token;
-    dispatch_once(&once_token, ^{
-      FIROptions* options = [[FIROptions alloc] initWithContentsOfFile:kPlist];
-      [FIRApp configureWithOptions:options];
-    });
+FIRApp* AppWithFakeUid(NSString* _Nullable uid) {
+  FIRApp* app = testutil::AppForUnitTesting();
+  app.getUIDImplementation = ^NSString* {
+    return uid;
+  };
+  return app;
+}
 
-    // Set getUID implementation.
-    FIRApp* default_app = [FIRApp defaultApp];
-    default_app.getUIDImplementation = ^NSString* {
-      return @"I'm a fake uid.";
-    };
-    app_ready_ = true;
-  }
+TEST(FirebaseCredentialsProviderTest, GetTokenUnauthenticated) {
+  FIRApp* app = AppWithFakeUid(nil);
 
-  bool app_ready_;
-};
+  FirebaseCredentialsProvider credentials_provider(app);
+  credentials_provider.GetToken(
+      /*force_refresh=*/true, [](Token token, const absl::string_view error) {
+        EXPECT_EQ("", token.token());
+        const User& user = token.user();
+        EXPECT_EQ("", user.uid());
+        EXPECT_FALSE(user.is_authenticated());
+        EXPECT_EQ("", error) << error;
+      });
+}
 
-// Set kPlist above before enable.
-TEST_F(FirebaseCredentialsProviderTest, GetToken) {
-  if (!app_ready_) {
-    return;
-  }
+TEST(FirebaseCredentialsProviderTest, GetToken) {
+  FIRApp* app = AppWithFakeUid(@"fake uid");
 
-  FirebaseCredentialsProvider credentials_provider([FIRApp defaultApp]);
+  FirebaseCredentialsProvider credentials_provider(app);
   credentials_provider.GetToken(
       /*force_refresh=*/true, [](Token token, const absl::string_view error) {
         EXPECT_EQ("", token.token());
         const User& user = token.user();
-        EXPECT_EQ("I'm a fake uid.", user.uid());
+        EXPECT_EQ("fake uid", user.uid());
         EXPECT_TRUE(user.is_authenticated());
         EXPECT_EQ("", error) << error;
       });
 }
 
-// Set kPlist above before enable.
-TEST_F(FirebaseCredentialsProviderTest, SetListener) {
-  if (!app_ready_) {
-    return;
-  }
+TEST(FirebaseCredentialsProviderTest, SetListener) {
+  FIRApp* app = AppWithFakeUid(@"fake uid");
 
-  FirebaseCredentialsProvider credentials_provider([FIRApp defaultApp]);
+  FirebaseCredentialsProvider credentials_provider(app);
   credentials_provider.SetUserChangeListener([](User user) {
-    EXPECT_EQ("I'm a fake uid.", user.uid());
+    EXPECT_EQ("fake uid", user.uid());
     EXPECT_TRUE(user.is_authenticated());
   });
 
-  // TODO(wilhuff): We should wait for the above expectations to actually happen
-  // before continuing.
-
   credentials_provider.SetUserChangeListener(nullptr);
 }
 
diff --git a/Firestore/core/test/firebase/firestore/testutil/CMakeLists.txt b/Firestore/core/test/firebase/firestore/testutil/CMakeLists.txt
new file mode 100644
index 0000000..b9fcd47
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/testutil/CMakeLists.txt
@@ -0,0 +1,35 @@
+# Copyright 2018 Google
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+cc_library(
+  firebase_firestore_testutil_apple
+  SOURCES
+    app_testing.h
+    app_testing.mm
+  DEPENDS
+    FirebaseCore
+    absl_strings
+)
+
+if(APPLE)
+  list(APPEND TESTUTIL_DEPENDS firebase_firestore_testutil_apple)
+endif()
+
+add_library(
+  firebase_firestore_testutil INTERFACE
+)
+target_link_libraries(
+  firebase_firestore_testutil INTERFACE
+  ${TESTUTIL_DEPENDS}
+)
diff --git a/Firestore/core/test/firebase/firestore/testutil/app_testing.h b/Firestore/core/test/firebase/firestore/testutil/app_testing.h
new file mode 100644
index 0000000..d18ba4f
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/testutil/app_testing.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2018 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FIRESTORE_CORE_TEST_FIREBASE_FIRESTORE_TESTUTIL_APP_TESTING_H_
+#define FIRESTORE_CORE_TEST_FIREBASE_FIRESTORE_TESTUTIL_APP_TESTING_H_
+
+#include "absl/strings/string_view.h"
+
+#if __OBJC__
+
+@class FIRApp;
+
+namespace firebase {
+namespace firestore {
+namespace testutil {
+
+/** Creates a set of default Firebase Options for testing. */
+FIROptions* OptionsForUnitTesting(
+    const absl::string_view project_id = "project_id");
+
+/** Creates a new Firebase App for testing. */
+FIRApp* AppForUnitTesting(const absl::string_view project_id = "project_id");
+
+}  // namespace testutil
+}  // namespace firestore
+}  // namespace firebase
+
+#endif  // __OBJC__
+
+#endif  // FIRESTORE_CORE_TEST_FIREBASE_FIRESTORE_TESTUTIL_APP_TESTING_H_
diff --git a/Firestore/core/test/firebase/firestore/testutil/app_testing.mm b/Firestore/core/test/firebase/firestore/testutil/app_testing.mm
new file mode 100644
index 0000000..21db0db
--- /dev/null
+++ b/Firestore/core/test/firebase/firestore/testutil/app_testing.mm
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2018 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import <FirebaseCore/FIRApp.h>
+#import <FirebaseCore/FIROptions.h>
+
+#include "Firestore/core/src/firebase/firestore/util/string_apple.h"
+#include "Firestore/core/test/firebase/firestore/testutil/app_testing.h"
+
+namespace firebase {
+namespace firestore {
+namespace testutil {
+
+FIROptions* OptionsForUnitTesting(const absl::string_view project_id) {
+  FIROptions* options =
+      [[FIROptions alloc] initWithGoogleAppID:@"1:123:ios:123ab"
+                                  GCMSenderID:@"gcm_sender_id"];
+  options.projectID = util::WrapNSString(project_id);
+  return options;
+}
+
+FIRApp* AppForUnitTesting(const absl::string_view project_id) {
+  static int counter = 0;
+
+  NSString* appName =
+      [NSString stringWithFormat:@"app_for_unit_testing_%d", counter++];
+  FIROptions* options = OptionsForUnitTesting(project_id);
+  [FIRApp configureWithName:appName options:options];
+
+  return [FIRApp appNamed:appName];
+}
+
+}  // namespace testutil
+}  // namespace firestore
+}  // namespace firebase
diff --git a/Firestore/test.sh b/Firestore/test.sh
index b211f46..7be70d0 100755
--- a/Firestore/test.sh
+++ b/Firestore/test.sh
@@ -40,19 +40,15 @@ test_iOS() {
 
 test_CMake() {
   echo "cpu core: $(sysctl -n hw.ncpu)"
-  echo "set cmake build" && \
-    mkdir build && \
+  echo "prepare cmake build" && \
+    mkdir -p build && \
     cd build && \
     cmake .. || \
     exit 1
 
-  echo "initial cmake build" && \
+  echo "cmake build and test" && \
     make -j $(sysctl -n hw.ncpu) all || \
     exit 2
-
-  echo "test Firestore cmake build" && \
-    cd Firestore && \
-    make test
 }
 
 test_iOS; RESULT=$?