Breaks Swift

Breaker.h

#import <Foundation/Foundation.h>

@class MyTester;

@interface Breaker: NSObject

@property (nonatomic) MyTester* tester;

- (void)breakSwift;

@end

Breaker.m

#import <Foundation/Foundation.h>
#import "blockerror-Swift.h"
#import "Breaker.h"

@implementation Breaker: NSObject

-(id)init {
    if (!(self = [super init])) {
        return nil;
    }
    
    MyTester* tester = [[MyTester alloc] init];
    self.tester = tester;
    
    [self breakSwift];
    
    return self;
}

-(void)breakSwift {
    __block int i;
    
    [[self tester] addAck:0](^(NSArray* data) {
        NSLog(@"breaing swift");
        
        i = 1 + 1;
        
        NSLog(@"%i", i);
    });
}

@end

Bridging-Header.h

#import "Breaker.h"

main.swift

import Foundation

public typealias Callback = (NSArray) -> Void

struct AckMap {
    private var acks = [Int: Callback]()
    
    mutating func addAck(num:Int, callback:Callback) {
        self.acks[num] = callback
    }
    
    mutating func executeAck(ack:Int, items:[AnyObject]) {
        self.acks[ack]?(items)
        self.acks.removeValueForKey(ack)
    }
}

public class MyTester: NSObject {
    var acks = AckMap()
    
    public func addAck(num:Int) -> (Callback) -> Void {
        return {[weak self] callback in
            callback([0])
            self?.acks.addAck(num, callback: callback)
            return
        }
    }
    
    public func breakObjc(num:Int) {
        self.acks.executeAck(num, items: ["break"])
    }
}

let breaker = Breaker()

breaker.tester.breakObjc(0)

Change Callback to

public typealias Callback = @objc_block (NSArray?) -> Void

and the crash goes away.