NSError+UsefulConstructors.m   [plain text]

/*
 * Copyright (c) 2018 Apple Inc. All Rights Reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
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 */


#import "NSError+UsefulConstructors.h"

@implementation NSError (UsefulConstructors)

+ (instancetype)errorWithDomain:(NSErrorDomain)domain code:(NSInteger)code description:(NSString*)description {
    return [NSError errorWithDomain:domain code:code description:description underlying:nil];
}

+ (instancetype)errorWithDomain:(NSErrorDomain)domain code:(NSInteger)code description:(NSString*)description underlying:(NSError*)underlying {
    // Obj-C throws a fit if there's nulls in dictionaries, so we can't use a dictionary literal here.
    // Use the null-assignment semantics of NSMutableDictionary to make a dictionary either with either, both, or neither key.
    NSMutableDictionary* mut = [[NSMutableDictionary alloc] init];
    mut[NSLocalizedDescriptionKey] = description;
    mut[NSUnderlyingErrorKey] = underlying;

    return [NSError errorWithDomain:domain code:code userInfo:mut];
}

@end