proof that NSSelectors are unique and different from their character representation

SelectorTests.m

//
//  SelectorTestTests.m
//  SelectorTestTests
//
//  Created by Heiko Behrens on 29.06.12.
//  Copyright (c) 2012 BeamApp. All rights reserved.
//

#import "SelectorTestTests.h"

@implementation SelectorTestTests

- (void)testSelector
{
    
    // create two different instances of NSStrings "selector"
    NSString* name1 = @"selector";
    NSString* name2 = [NSString stringWithFormat:@"%@%@", @"sel", @"ector"];
    STAssertEqualObjects(name1, name2, @"equal strings");
    STAssertTrue(name1 != name2, @"different string instances");
    
    // NSSelectorFromString returns *same* selector
    SEL sel_name1 = NSSelectorFromString(name1);
    SEL sel_name2 = NSSelectorFromString(name2);
    STAssertEqualObjects(NSStringFromSelector(sel_name1), NSStringFromSelector(sel_name2), @"equals selectors");
    STAssertTrue(sel_name1 == sel_name2, @"same selector");
    
    // create two different pointers to char[] "selector"
    const char* char1 = [name1 UTF8String];
    const char* char2 = [name2 UTF8String];
    STAssertTrue(name1 != name2, @"different char* pointers");
    
    // sel_registerName returns *same* selector
    // => does not return same char again
    SEL sel_char1 = sel_registerName(char1);
    SEL sel_char2 = sel_registerName(char2);
    STAssertEqualObjects(NSStringFromSelector(sel_char1), NSStringFromSelector(sel_char2), @"equals selectors");
    STAssertTrue(sel_char1 == sel_char2, @"same selector");
    
    // verify in the logs that this test will actually be executed
    STFail(@"findme"); 
}

@end