Add lint checking for Objective-C++ sources (#1048)

* lint.sh now lints Objective-C++ too

* cpplint checks system-style includes that should be user-style

This prevents it from recognizing project sources as if they were C
system headers and then complaining that they're in the wrong place.

* cpplint checks #imports and #includes

* cpplint checks that C++ system headers aren't #imported

* cpplint checks for C system headers that could be C++ system headers

* cpplint checks that Objective-C sources include their headers

20 files changed, 59 insertions, 41 deletions

diff --git a/Firestore/Example/Tests/Core/FSTQueryListenerTests.mm b/Firestore/Example/Tests/Core/FSTQueryListenerTests.mm
index bc253d0..0454152 100644
--- a/Firestore/Example/Tests/Core/FSTQueryListenerTests.mm
+++ b/Firestore/Example/Tests/Core/FSTQueryListenerTests.mm
@@ -14,10 +14,9 @@
  * limitations under the License.
  */
 
-#import "Firestore/Source/Core/FSTEventManager.h"
-
 #import <XCTest/XCTest.h>
 
+#import "Firestore/Source/Core/FSTEventManager.h"
 #import "Firestore/Source/Core/FSTQuery.h"
 #import "Firestore/Source/Core/FSTView.h"
 #import "Firestore/Source/Model/FSTDocument.h"
diff --git a/Firestore/Example/Tests/Core/FSTSyncEngine+Testing.h b/Firestore/Example/Tests/Core/FSTSyncEngine+Testing.h
index 6e7c45b..5d5c981 100644
--- a/Firestore/Example/Tests/Core/FSTSyncEngine+Testing.h
+++ b/Firestore/Example/Tests/Core/FSTSyncEngine+Testing.h
@@ -16,6 +16,8 @@
 
 #import <Foundation/Foundation.h>
 
+#include <map>
+
 #import "Firestore/Source/Core/FSTSyncEngine.h"
 
 #include "Firestore/core/src/firebase/firestore/model/document_key.h"
diff --git a/Firestore/Example/Tests/GoogleTest/FSTGoogleTestTests.mm b/Firestore/Example/Tests/GoogleTest/FSTGoogleTestTests.mm
index 18dfaf3..ec14880 100644
--- a/Firestore/Example/Tests/GoogleTest/FSTGoogleTestTests.mm
+++ b/Firestore/Example/Tests/GoogleTest/FSTGoogleTestTests.mm
@@ -17,9 +17,9 @@
 #import <XCTest/XCTest.h>
 #import <objc/runtime.h>
 
-#include <gtest/gtest.h>
+#import "Firestore/Source/Util/FSTAssert.h"
 
-#include "Firestore/Source/Util/FSTAssert.h"
+#include "gtest/gtest.h"
 
 /**
  * An XCTest test case that finds C++ test cases written in the GoogleTest framework, runs them, and
diff --git a/Firestore/Example/Tests/Local/FSTEagerGarbageCollectorTests.mm b/Firestore/Example/Tests/Local/FSTEagerGarbageCollectorTests.mm
index 2cf530c..615b3f6 100644
--- a/Firestore/Example/Tests/Local/FSTEagerGarbageCollectorTests.mm
+++ b/Firestore/Example/Tests/Local/FSTEagerGarbageCollectorTests.mm
@@ -16,10 +16,10 @@
 
 #import "Firestore/Source/Local/FSTEagerGarbageCollector.h"
 
-#include <set>
-
 #import <XCTest/XCTest.h>
 
+#include <set>
+
 #import "Firestore/Source/Local/FSTReferenceSet.h"
 #import "Firestore/Source/Model/FSTDocumentKey.h"
 
diff --git a/Firestore/Example/Tests/Local/FSTLevelDBKeyTests.mm b/Firestore/Example/Tests/Local/FSTLevelDBKeyTests.mm
index f23b7c5..c4b7e29 100644
--- a/Firestore/Example/Tests/Local/FSTLevelDBKeyTests.mm
+++ b/Firestore/Example/Tests/Local/FSTLevelDBKeyTests.mm
@@ -18,6 +18,8 @@
 
 #import <XCTest/XCTest.h>
 
+#include <string>
+
 #import "Firestore/Example/Tests/Util/FSTHelpers.h"
 
 #include "Firestore/core/src/firebase/firestore/util/string_apple.h"
diff --git a/Firestore/Example/Tests/Local/FSTLevelDBLocalStoreTests.mm b/Firestore/Example/Tests/Local/FSTLevelDBLocalStoreTests.mm
index 97e3c5b..29caa84 100644
--- a/Firestore/Example/Tests/Local/FSTLevelDBLocalStoreTests.mm
+++ b/Firestore/Example/Tests/Local/FSTLevelDBLocalStoreTests.mm
@@ -14,13 +14,10 @@
  * limitations under the License.
  */
 
-#import "Firestore/Source/Local/FSTLocalStore.h"
-
-#import <XCTest/XCTest.h>
+#import "Firestore/Example/Tests/Local/FSTLocalStoreTests.h"
 
 #import "Firestore/Source/Local/FSTLevelDB.h"
 
-#import "Firestore/Example/Tests/Local/FSTLocalStoreTests.h"
 #import "Firestore/Example/Tests/Local/FSTPersistenceTestHelpers.h"
 
 NS_ASSUME_NONNULL_BEGIN
diff --git a/Firestore/Example/Tests/Local/FSTLevelDBMigrationsTests.mm b/Firestore/Example/Tests/Local/FSTLevelDBMigrationsTests.mm
index 14910ce..3da8083 100644
--- a/Firestore/Example/Tests/Local/FSTLevelDBMigrationsTests.mm
+++ b/Firestore/Example/Tests/Local/FSTLevelDBMigrationsTests.mm
@@ -16,11 +16,15 @@
 
 #import <XCTest/XCTest.h>
 
+#include <memory>
+#include <string>
+
 #import "Firestore/Protos/objc/firestore/local/Target.pbobjc.h"
 #import "Firestore/Source/Local/FSTLevelDB.h"
 #import "Firestore/Source/Local/FSTLevelDBKey.h"
 #import "Firestore/Source/Local/FSTLevelDBMigrations.h"
 #import "Firestore/Source/Local/FSTLevelDBQueryCache.h"
+
 #include "Firestore/core/src/firebase/firestore/util/ordered_code.h"
 #include "leveldb/db.h"
 
diff --git a/Firestore/Example/Tests/Local/FSTLevelDBMutationQueueTests.mm b/Firestore/Example/Tests/Local/FSTLevelDBMutationQueueTests.mm
index cd8176e..60d9800 100644
--- a/Firestore/Example/Tests/Local/FSTLevelDBMutationQueueTests.mm
+++ b/Firestore/Example/Tests/Local/FSTLevelDBMutationQueueTests.mm
@@ -17,7 +17,8 @@
 #import "Firestore/Source/Local/FSTLevelDBMutationQueue.h"
 
 #import <XCTest/XCTest.h>
-#include <leveldb/db.h>
+
+#include <string>
 
 #import "Firestore/Protos/objc/firestore/local/Mutation.pbobjc.h"
 #import "Firestore/Source/Local/FSTLevelDB.h"
@@ -28,6 +29,7 @@
 
 #include "Firestore/core/src/firebase/firestore/auth/user.h"
 #include "Firestore/core/src/firebase/firestore/util/ordered_code.h"
+#include "leveldb/db.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
diff --git a/Firestore/Example/Tests/Local/FSTLevelDBRemoteDocumentCacheTests.mm b/Firestore/Example/Tests/Local/FSTLevelDBRemoteDocumentCacheTests.mm
index d69e613..7baf1ef 100644
--- a/Firestore/Example/Tests/Local/FSTLevelDBRemoteDocumentCacheTests.mm
+++ b/Firestore/Example/Tests/Local/FSTLevelDBRemoteDocumentCacheTests.mm
@@ -14,16 +14,15 @@
  * limitations under the License.
  */
 
-#import "Firestore/Example/Tests/Local/FSTRemoteDocumentCacheTests.h"
-
-#include <leveldb/db.h>
+#include <string>
 
+#import "Firestore/Example/Tests/Local/FSTPersistenceTestHelpers.h"
+#import "Firestore/Example/Tests/Local/FSTRemoteDocumentCacheTests.h"
 #import "Firestore/Source/Local/FSTLevelDB.h"
 #import "Firestore/Source/Local/FSTLevelDBKey.h"
 
-#import "Firestore/Example/Tests/Local/FSTPersistenceTestHelpers.h"
-
 #include "Firestore/core/src/firebase/firestore/util/ordered_code.h"
+#include "leveldb/db.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
diff --git a/Firestore/Example/Tests/Local/FSTLevelDBTransactionTests.mm b/Firestore/Example/Tests/Local/FSTLevelDBTransactionTests.mm
index a32ce9f..29f5d6c 100644
--- a/Firestore/Example/Tests/Local/FSTLevelDBTransactionTests.mm
+++ b/Firestore/Example/Tests/Local/FSTLevelDBTransactionTests.mm
@@ -14,15 +14,23 @@
  * limitations under the License.
  */
 
+#import <XCTest/XCTest.h>
+
+#include <memory>
+#include <string>
+
+// This is out of order to satisfy the linter, which doesn't realize this is
+// the header corresponding to this test.
+// TODO(wilhuff): move this to the top once the test filename matches
 #include "Firestore/core/src/firebase/firestore/local/leveldb_transaction.h"
 
-#import <XCTest/XCTest.h>
-#include <absl/strings/string_view.h>
-#include <leveldb/db.h>
 #import "Firestore/Example/Tests/Local/FSTPersistenceTestHelpers.h"
 #import "Firestore/Protos/objc/firestore/local/Mutation.pbobjc.h"
 #import "Firestore/Protos/objc/firestore/local/Target.pbobjc.h"
+
 #include "Firestore/core/src/firebase/firestore/local/leveldb_key.h"
+#include "absl/strings/string_view.h"
+#include "leveldb/db.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
diff --git a/Firestore/Example/Tests/Local/FSTLocalStoreTests.h b/Firestore/Example/Tests/Local/FSTLocalStoreTests.h
index 8e06d82..e514954 100644
--- a/Firestore/Example/Tests/Local/FSTLocalStoreTests.h
+++ b/Firestore/Example/Tests/Local/FSTLocalStoreTests.h
@@ -16,7 +16,9 @@
 
 #import <XCTest/XCTest.h>
 
-@class FSTLocalStore;
+#import "Firestore/Source/Local/FSTLocalStore.h"
+
+@protocol FSTPersistence;
 
 NS_ASSUME_NONNULL_BEGIN
 
diff --git a/Firestore/Example/Tests/Local/FSTMemoryLocalStoreTests.mm b/Firestore/Example/Tests/Local/FSTMemoryLocalStoreTests.mm
index b78239e..7708eed 100644
--- a/Firestore/Example/Tests/Local/FSTMemoryLocalStoreTests.mm
+++ b/Firestore/Example/Tests/Local/FSTMemoryLocalStoreTests.mm
@@ -14,13 +14,10 @@
  * limitations under the License.
  */
 
-#import "Firestore/Source/Local/FSTLocalStore.h"
-
-#import <XCTest/XCTest.h>
+#import "Firestore/Example/Tests/Local/FSTLocalStoreTests.h"
 
 #import "Firestore/Source/Local/FSTMemoryPersistence.h"
 
-#import "Firestore/Example/Tests/Local/FSTLocalStoreTests.h"
 #import "Firestore/Example/Tests/Local/FSTPersistenceTestHelpers.h"
 
 NS_ASSUME_NONNULL_BEGIN
diff --git a/Firestore/Example/Tests/Local/FSTMutationQueueTests.mm b/Firestore/Example/Tests/Local/FSTMutationQueueTests.mm
index b228657..5b5bdd1 100644
--- a/Firestore/Example/Tests/Local/FSTMutationQueueTests.mm
+++ b/Firestore/Example/Tests/Local/FSTMutationQueueTests.mm
@@ -17,6 +17,9 @@
 #import "Firestore/Example/Tests/Local/FSTMutationQueueTests.h"
 
 #import <FirebaseFirestore/FIRTimestamp.h>
+
+#include <set>
+
 #import "Firestore/Source/Core/FSTQuery.h"
 #import "Firestore/Source/Local/FSTEagerGarbageCollector.h"
 #import "Firestore/Source/Local/FSTMutationQueue.h"
@@ -246,7 +249,6 @@ NS_ASSUME_NONNULL_BEGIN
         return newBatches;
       });
   self.persistence.run("testNextMutationBatchAfterBatchIDSkipsAcknowledgedBatches", [&]() {
-
     [self.mutationQueue acknowledgeBatch:batches[0] streamToken:nil];
     XCTAssertEqualObjects([self.mutationQueue nextMutationBatchAfterBatchID:kFSTBatchIDUnknown],
                           batches[1]);
diff --git a/Firestore/Example/Tests/Local/FSTQueryCacheTests.mm b/Firestore/Example/Tests/Local/FSTQueryCacheTests.mm
index 956afa9..429a83a 100644
--- a/Firestore/Example/Tests/Local/FSTQueryCacheTests.mm
+++ b/Firestore/Example/Tests/Local/FSTQueryCacheTests.mm
@@ -16,6 +16,8 @@
 
 #import "Firestore/Example/Tests/Local/FSTQueryCacheTests.h"
 
+#include <set>
+
 #import "Firestore/Source/Core/FSTQuery.h"
 #import "Firestore/Source/Core/FSTSnapshotVersion.h"
 #import "Firestore/Source/Local/FSTEagerGarbageCollector.h"
diff --git a/Firestore/Example/Tests/Local/StringViewTests.mm b/Firestore/Example/Tests/Local/StringViewTests.mm
index b30b43d..7c86924 100644
--- a/Firestore/Example/Tests/Local/StringViewTests.mm
+++ b/Firestore/Example/Tests/Local/StringViewTests.mm
@@ -17,7 +17,8 @@
 #import "Firestore/Source/Local/StringView.h"
 
 #import <XCTest/XCTest.h>
-#include <leveldb/slice.h>
+
+#include "leveldb/slice.h"
 
 using Firestore::StringView;
 
diff --git a/Firestore/Example/Tests/Model/FSTFieldValueTests.mm b/Firestore/Example/Tests/Model/FSTFieldValueTests.mm
index 98504b5..d16a01d 100644
--- a/Firestore/Example/Tests/Model/FSTFieldValueTests.mm
+++ b/Firestore/Example/Tests/Model/FSTFieldValueTests.mm
@@ -22,7 +22,6 @@
 
 #import "Firestore/Source/API/FIRFirestore+Internal.h"
 #import "Firestore/Source/API/FSTUserDataConverter.h"
-#import "Firestore/Source/Model/FSTFieldValue.h"
 
 #import "Firestore/Example/Tests/API/FSTAPIHelpers.h"
 #import "Firestore/Example/Tests/Util/FSTHelpers.h"
diff --git a/Firestore/Example/Tests/SpecTests/FSTSpecTests.mm b/Firestore/Example/Tests/SpecTests/FSTSpecTests.mm
index f66e6c7..128f825 100644
--- a/Firestore/Example/Tests/SpecTests/FSTSpecTests.mm
+++ b/Firestore/Example/Tests/SpecTests/FSTSpecTests.mm
@@ -16,12 +16,12 @@
 
 #import "Firestore/Example/Tests/SpecTests/FSTSpecTests.h"
 
-#include <map>
-#include <utility>
-
 #import <FirebaseFirestore/FIRFirestoreErrors.h>
 #import <GRPCClient/GRPCCall.h>
 
+#include <map>
+#include <utility>
+
 #import "Firestore/Source/Core/FSTEventManager.h"
 #import "Firestore/Source/Core/FSTQuery.h"
 #import "Firestore/Source/Core/FSTSnapshotVersion.h"
diff --git a/Firestore/Example/Tests/SpecTests/FSTSyncEngineTestDriver.mm b/Firestore/Example/Tests/SpecTests/FSTSyncEngineTestDriver.mm
index 91140bf..f167ce5 100644
--- a/Firestore/Example/Tests/SpecTests/FSTSyncEngineTestDriver.mm
+++ b/Firestore/Example/Tests/SpecTests/FSTSyncEngineTestDriver.mm
@@ -16,12 +16,12 @@
 
 #import "Firestore/Example/Tests/SpecTests/FSTSyncEngineTestDriver.h"
 
-#include <map>
-#include <unordered_map>
-
 #import <FirebaseFirestore/FIRFirestoreErrors.h>
 #import <GRPCClient/GRPCCall.h>
 
+#include <map>
+#include <unordered_map>
+
 #import "Firestore/Source/Core/FSTEventManager.h"
 #import "Firestore/Source/Core/FSTQuery.h"
 #import "Firestore/Source/Core/FSTSnapshotVersion.h"
diff --git a/Firestore/Example/Tests/Util/FSTHelpers.mm b/Firestore/Example/Tests/Util/FSTHelpers.mm
index cc120a9..8f170e6 100644
--- a/Firestore/Example/Tests/Util/FSTHelpers.mm
+++ b/Firestore/Example/Tests/Util/FSTHelpers.mm
@@ -16,15 +16,16 @@
 
 #import "Firestore/Example/Tests/Util/FSTHelpers.h"
 
-#include <inttypes.h>
-#include <list>
-#include <map>
-#include <vector>
-
 #import <FirebaseFirestore/FIRFieldPath.h>
 #import <FirebaseFirestore/FIRGeoPoint.h>
 #import <FirebaseFirestore/FIRTimestamp.h>
 
+#include <cinttypes>
+#include <list>
+#include <map>
+#include <utility>
+#include <vector>
+
 #import "Firestore/Source/API/FIRFieldPath+Internal.h"
 #import "Firestore/Source/API/FSTUserDataConverter.h"
 #import "Firestore/Source/Core/FSTQuery.h"
diff --git a/Firestore/Example/Tests/Util/FSTIntegrationTestCase.mm b/Firestore/Example/Tests/Util/FSTIntegrationTestCase.mm
index 611bcc8..79163da 100644
--- a/Firestore/Example/Tests/Util/FSTIntegrationTestCase.mm
+++ b/Firestore/Example/Tests/Util/FSTIntegrationTestCase.mm
@@ -16,14 +16,15 @@
 
 #import "Firestore/Example/Tests/Util/FSTIntegrationTestCase.h"
 
-#include <memory>
-#include <utility>
-
 #import <FirebaseCore/FIRLogger.h>
 #import <FirebaseFirestore/FirebaseFirestore-umbrella.h>
 #import <GRPCClient/GRPCCall+ChannelArg.h>
 #import <GRPCClient/GRPCCall+Tests.h>
 
+#include <memory>
+#include <string>
+#include <utility>
+
 #include "Firestore/core/src/firebase/firestore/auth/empty_credentials_provider.h"
 #include "Firestore/core/src/firebase/firestore/model/database_id.h"
 #include "Firestore/core/src/firebase/firestore/util/autoid.h"