ReactiveCocoaFramework/ReactiveCocoaTests/RACTestSchedulerSpec.m

//
//  RACTestSchedulerSpec.m
//  ReactiveCocoa
//
//  Created by Justin Spahr-Summers on 2013-07-06.
//  Copyright (c) 2013 GitHub, Inc. All rights reserved.
//

#import "RACTestScheduler.h"

SpecBegin(RACTestScheduler)

__block RACTestScheduler *scheduler;

beforeEach(^{
	scheduler = [[RACTestScheduler alloc] init];
	expect(scheduler).notTo.beNil();
});

it(@"should do nothing when stepping while empty", ^{
	[scheduler step];
	[scheduler step:5];
	[scheduler stepAll];
});

it(@"should execute the earliest enqueued block when stepping", ^{
	__block BOOL firstExecuted = NO;
	[scheduler schedule:^{
		firstExecuted = YES;
	}];

	__block BOOL secondExecuted = NO;
	[scheduler schedule:^{
		secondExecuted = YES;
	}];

	expect(firstExecuted).to.beFalsy();
	expect(secondExecuted).to.beFalsy();

	[scheduler step];
	expect(firstExecuted).to.beTruthy();
	expect(secondExecuted).to.beFalsy();

	[scheduler step];
	expect(secondExecuted).to.beTruthy();
});

it(@"should step multiple times", ^{
	__block BOOL firstExecuted = NO;
	[scheduler schedule:^{
		firstExecuted = YES;
	}];

	__block BOOL secondExecuted = NO;
	[scheduler schedule:^{
		secondExecuted = YES;
	}];

	__block BOOL thirdExecuted = NO;
	[scheduler schedule:^{
		thirdExecuted = YES;
	}];

	expect(firstExecuted).to.beFalsy();
	expect(secondExecuted).to.beFalsy();
	expect(thirdExecuted).to.beFalsy();

	[scheduler step:2];
	expect(firstExecuted).to.beTruthy();
	expect(secondExecuted).to.beTruthy();
	expect(thirdExecuted).to.beFalsy();

	[scheduler step:1];
	expect(thirdExecuted).to.beTruthy();
});

it(@"should step through all scheduled blocks", ^{
	__block NSUInteger executions = 0;
	for (NSUInteger i = 0; i < 10; i++) {
		[scheduler schedule:^{
			executions++;
		}];
	}

	expect(executions).to.equal(0);

	[scheduler stepAll];
	expect(executions).to.equal(10);
});

it(@"should execute blocks in date order when stepping", ^{
	__block BOOL laterExecuted = NO;
	[scheduler after:[NSDate distantFuture] schedule:^{
		laterExecuted = YES;
	}];

	__block BOOL earlierExecuted = NO;
	[scheduler after:[NSDate dateWithTimeIntervalSinceNow:20] schedule:^{
		earlierExecuted = YES;
	}];

	expect(earlierExecuted).to.beFalsy();
	expect(laterExecuted).to.beFalsy();

	[scheduler step];
	expect(earlierExecuted).to.beTruthy();
	expect(laterExecuted).to.beFalsy();

	[scheduler step];
	expect(laterExecuted).to.beTruthy();
});

it(@"should execute delayed blocks in date order when stepping", ^{
	__block BOOL laterExecuted = NO;
	[scheduler afterDelay:100 schedule:^{
		laterExecuted = YES;
	}];

	__block BOOL earlierExecuted = NO;
	[scheduler afterDelay:50 schedule:^{
		earlierExecuted = YES;
	}];

	expect(earlierExecuted).to.beFalsy();
	expect(laterExecuted).to.beFalsy();

	[scheduler step];
	expect(earlierExecuted).to.beTruthy();
	expect(laterExecuted).to.beFalsy();

	[scheduler step];
	expect(laterExecuted).to.beTruthy();
});

it(@"should execute a repeating blocks in date order", ^{
	__block NSUInteger firstExecutions = 0;
	[scheduler after:[NSDate dateWithTimeIntervalSinceNow:20] repeatingEvery:5 withLeeway:0 schedule:^{
		firstExecutions++;
	}];

	__block NSUInteger secondExecutions = 0;
	[scheduler after:[NSDate dateWithTimeIntervalSinceNow:22] repeatingEvery:10 withLeeway:0 schedule:^{
		secondExecutions++;
	}];

	expect(firstExecutions).to.equal(0);
	expect(secondExecutions).to.equal(0);

	// 20 ticks
	[scheduler step];
	expect(firstExecutions).to.equal(1);
	expect(secondExecutions).to.equal(0);

	// 22 ticks
	[scheduler step];
	expect(firstExecutions).to.equal(1);
	expect(secondExecutions).to.equal(1);

	// 25 ticks
	[scheduler step];
	expect(firstExecutions).to.equal(2);
	expect(secondExecutions).to.equal(1);

	// 30 ticks
	[scheduler step];
	expect(firstExecutions).to.equal(3);
	expect(secondExecutions).to.equal(1);

	// 32 ticks
	[scheduler step];
	expect(firstExecutions).to.equal(3);
	expect(secondExecutions).to.equal(2);
});

SpecEnd