firebase-ios-sdk/FirebaseDatabase/Tests/Unit/FConnectionTest.m

/*
 * Copyright 2026 Google LLC
 *
 * 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 <XCTest/XCTest.h>

#import "FirebaseDatabase/Sources/Constants/FConstants.h"
#import "FirebaseDatabase/Sources/Core/FRepoInfo.h"
#import "FirebaseDatabase/Sources/Realtime/FConnection.h"

// onControl: and onHandshake: are internal to FConnection; expose them so the
// malformed-frame handling can be exercised directly.
@interface FConnection (Testing)

- (void)onControl:(NSDictionary *)message;
- (void)onHandshake:(NSDictionary *)handshake;

@end

@interface FConnectionTestDelegate : NSObject <FConnectionDelegate>
@property(nonatomic) BOOL didBecomeReady;
@property(nonatomic) BOOL didReceiveDataMessage;
@property(nonatomic) BOOL didDisconnect;
@end

@implementation FConnectionTestDelegate
- (void)onReady:(FConnection *)fconnection
         atTime:(NSNumber *)timestamp
      sessionID:(NSString *)sessionID {
  self.didBecomeReady = YES;
}
- (void)onDataMessage:(FConnection *)fconnection withMessage:(NSDictionary *)message {
  self.didReceiveDataMessage = YES;
}
- (void)onDisconnect:(FConnection *)fconnection withReason:(FDisconnectReason)reason {
  self.didDisconnect = YES;
}
- (void)onKill:(FConnection *)fconnection withReason:(NSString *)reason {
}
@end

@interface FConnectionTest : XCTestCase
@end

@implementation FConnectionTest

- (FRepoInfo *)makeRepoInfo {
  return [[FRepoInfo alloc] initWithHost:@"foo.firebaseio.com" isSecure:YES withNamespace:@"foo"];
}

- (FConnection *)connectionWithDelegate:(FConnectionTestDelegate *)delegate {
  return [self connectionWithRepoInfo:[self makeRepoInfo] delegate:delegate];
}

- (FConnection *)connectionWithRepoInfo:(FRepoInfo *)info
                               delegate:(FConnectionTestDelegate *)delegate {
  FConnection *connection = [[FConnection alloc] initWith:info
                                         andDispatchQueue:dispatch_get_main_queue()
                                              googleAppID:@"1:1234:ios:1234"
                                            lastSessionID:nil
                                            appCheckToken:nil];
  connection.delegate = delegate;
  return connection;
}

// A frame is parsed straight from server JSON, so a non-object frame (e.g. a
// JSON array) does not respond to -objectForKey: and would previously crash the
// client. It should now be ignored.
- (void)testNonDictionaryServerMessageIsIgnored {
  FConnectionTestDelegate *delegate = [[FConnectionTestDelegate alloc] init];
  FConnection *connection = [self connectionWithDelegate:delegate];

  NSArray *arrayFrame = @[ @1, @2, @3 ];
  XCTAssertNoThrow([connection onMessage:nil withMessage:(id)arrayFrame]);
  XCTAssertNoThrow([connection onMessage:nil withMessage:(id) @"not a dict"]);
  XCTAssertFalse(delegate.didReceiveDataMessage);
}

- (void)testControlMessageWithMalformedTypeIsIgnored {
  FConnectionTestDelegate *delegate = [[FConnectionTestDelegate alloc] init];
  FConnection *connection = [self connectionWithDelegate:delegate];

  // Control payload is not a JSON object.
  XCTAssertNoThrow([connection onControl:(id) @"not a dict"]);
  // Control payload has a non-string type.
  NSDictionary *nonStringType = @{kFWPAsyncServerControlMessageType : @5};
  XCTAssertNoThrow([connection onControl:nonStringType]);
}

// A malformed handshake can't move the connection into the connected state, so
// it closes the connection and lets the normal retry logic reconnect. A closed
// FConnection stays closed, so every case runs against a fresh one.
- (void)testMalformedHandshakeClosesConnection {
  // Handshake is not a JSON object.
  [self assertHandshakeClosesConnection:@"not a dict" repoInfo:[self makeRepoInfo]];

  // Handshake with a non-numeric timestamp.
  NSDictionary *nonNumericTimestamp = @{kFWPAsyncServerHelloTimestamp : @"soon"};
  [self assertHandshakeClosesConnection:nonNumericTimestamp repoInfo:[self makeRepoInfo]];

  // Handshake with a non-string host. The bad host must not replace the one the
  // repo info already has.
  NSDictionary *nonStringHost =
      @{kFWPAsyncServerHelloTimestamp : @123, kFWPAsyncServerHelloConnectedHost : @5};
  FRepoInfo *info = [self makeRepoInfo];
  NSString *internalHost = info.internalHost;
  [self assertHandshakeClosesConnection:nonStringHost repoInfo:info];
  XCTAssertEqualObjects(info.internalHost, internalHost);
}

- (void)assertHandshakeClosesConnection:(id)handshake repoInfo:(FRepoInfo *)info {
  FConnectionTestDelegate *delegate = [[FConnectionTestDelegate alloc] init];
  FConnection *connection = [self connectionWithRepoInfo:info delegate:delegate];

  XCTAssertNoThrow([connection onHandshake:handshake], @"handshake: %@", handshake);
  XCTAssertTrue(delegate.didDisconnect, @"handshake: %@", handshake);
  XCTAssertFalse(delegate.didBecomeReady, @"handshake: %@", handshake);
}

@end