firebase-ios-sdk/Example/Database/Tests/Helpers/SenTest+FWaiter.m

/*
 * Copyright 2017 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 "SenTest+FWaiter.h"
#import "FTestContants.h"

@implementation XCTestCase (FWaiter)

- (NSTimeInterval) waitUntil:(BOOL (^)())predicate {
    return [self waitUntil:predicate timeout:kFirebaseTestWaitUntilTimeout description:nil];
}

- (NSTimeInterval) waitUntil:(BOOL (^)())predicate description:(NSString*)desc {
    return [self waitUntil:predicate timeout:kFirebaseTestWaitUntilTimeout description:desc];
}

- (NSTimeInterval) waitUntil:(BOOL (^)())predicate timeout:(NSTimeInterval)seconds {
    return [self waitUntil:predicate timeout:seconds description:nil];
}

- (NSTimeInterval) waitUntil:(BOOL (^)())predicate timeout:(NSTimeInterval)seconds description:(NSString*)desc {
    NSTimeInterval start = [NSDate timeIntervalSinceReferenceDate];
    NSDate *timeoutDate = [NSDate dateWithTimeIntervalSinceNow:seconds];
    NSTimeInterval timeoutTime = [timeoutDate timeIntervalSinceReferenceDate];
    NSTimeInterval currentTime;

    for (currentTime = [NSDate timeIntervalSinceReferenceDate];
         !predicate() && currentTime < timeoutTime;
         currentTime = [NSDate timeIntervalSinceReferenceDate]) {
        [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate dateWithTimeIntervalSinceNow:0.25]];
    }

    NSTimeInterval finish = [NSDate timeIntervalSinceReferenceDate];
    if (currentTime > timeoutTime) {
        if (desc != nil) {
            XCTFail("Timed out on: %@", desc);
        } else {
            XCTFail("Timed out");
        }
    }
    return (finish - start);
}

@end