output.md

unit testing.mm

#import <Foundation/Foundation.h>
#import <objc/runtime.h>
#import <stdlib.h>

#define ANSI_COLOR_RED     "\x1b[31m"
#define ANSI_COLOR_GREEN   "\x1b[32m"
#define ANSI_COLOR_YELLOW  "\x1b[33m"
#define ANSI_COLOR_BLUE    "\x1b[34m"
#define ANSI_COLOR_MAGENTA "\x1b[35m"
#define ANSI_COLOR_CYAN    "\x1b[36m"
#define ANSI_COLOR_RESET   "\x1b[0m"

#define SuppressPerformSelectorLeakWarning(code...) \
    _Pragma("clang diagnostic push") \
    _Pragma("clang diagnostic ignored \"-Warc-performSelector-leaks\"") \
    code \
    _Pragma("clang diagnostic pop")

NSString * const kTestFailedException = @"TestFailedException";

#define TLog(format, args...) NSLog(@"       * " format,  ##args)

#define TAssert(cond, format, args...) do { \
    if(cond) \
        TLog(@"Assertion: " format ANSI_COLOR_GREEN "\tSuccessful"ANSI_COLOR_RESET, ##args); \
    else { \
        TLog(@"Assertion: " format ANSI_COLOR_RED "\tFAILED" ANSI_COLOR_RESET, ##args); \
        @throw [NSException exceptionWithName:kTestFailedException \
                                       reason:[NSString stringWithFormat:@"%s failed", #cond] \
                                     userInfo:nil]; \
    } \
} while(0)

#define Describe(entity, contexts...) \
@interface Test##entity : Test \
@end \
@implementation Test##entity \
    + (NSString *)entityName { \
        return [@#entity stringByReplacingOccurrencesOfString:@"_" withString:@" "]; \
    } \
    contexts \
@end

#define When(context, tests...) \
    - (TestResult *)When_##context { \
        TestResult *result = [TestResult new]; \
        tests \
        return result; \
    }

#define It(description, code...) ^{\
    @try { \
        result.totalTests += 1; \
        NSLog(@"     * It %@", [@#description stringByReplacingOccurrencesOfString:@"_" withString:@" "]); \
        code \
    } \
    @catch(NSException *e) { \
        result.failedTests += 1; \
    } \
}();

@interface TestResult : NSObject
@property NSUInteger totalTests, failedTests;
@end
@implementation TestResult
@end

@interface Test : NSObject
+ (BOOL)performTests;
+ (NSString *)entityName;
- (void)setUp;
- (void)tearDown;
@end

@implementation Test

+ (BOOL)performTests
{
    if(self == [Test class]) {
        int const classCount = objc_getClassList(NULL, 0);
        Class * const classes = (__unsafe_unretained Class *)malloc(sizeof(Class) * classCount);
        objc_getClassList(classes, classCount);
        
        NSUInteger totalTestClasses = 0;
        NSUInteger failedTestClasses= 0;
        for(int i = 0; i < classCount; ++i) {
            Class klass = classes[i];
            while((klass = class_getSuperclass(klass))) {
                if(klass == self) {
                    NSLog(@" * Checking '%@'", [classes[i] entityName]);
                    ++totalTestClasses;
                    if(![classes[i] performTests])
                        ++failedTestClasses;
                    break;
                }
            }
        }
        free(classes);
        
        NSLog(@"\n");
        if(failedTestClasses == 0) {
            NSLog(@"" ANSI_COLOR_GREEN " * All tests succeeded" ANSI_COLOR_RESET);
        } else {
            NSLog(@"" ANSI_COLOR_RED   " * Tests failed" ANSI_COLOR_RESET);
        }
    } else {
        Method *methods = class_copyMethodList(self, NULL);
        Method *method = methods;
        
        id instance = [self new];
        NSUInteger totalTests      = 0;
        NSUInteger failedTests = 0;
        while(*method) {
            SEL const selector = method_getName(*method);
            NSString * const selectorAsString = NSStringFromSelector(selector);
            if([selectorAsString hasPrefix:@"When_"]) {
                NSLog(@"   * %@:", [selectorAsString stringByReplacingOccurrencesOfString:@"_" withString:@" "]);
                [instance setUp];
    
                SuppressPerformSelectorLeakWarning(
                    TestResult * const result = [instance performSelector:selector];
                )
                totalTests += result.totalTests;
                failedTests += result.failedTests;
                
                [instance tearDown];
            }
            ++method;
        }
        free(methods);
        if(failedTests == 0)
            NSLog(@"" ANSI_COLOR_GREEN "   * %ld/%ld succeeded" ANSI_COLOR_RESET, totalTests - failedTests, totalTests);
        else {
            NSLog(@"" ANSI_COLOR_RED   "   * %ld/%ld succeeded" ANSI_COLOR_RESET, totalTests - failedTests, totalTests);
            return NO;
        }

    }
    return YES;
}

+ (NSString *)entityName
{
    return nil;
}

- (void)setUp    { return; }
- (void)tearDown { return; }
@end

Describe(NSString,
    When(newly_created,
        It(should_be_zero_length,
            TAssert(NO, @"defy reality");
        )
        It(should_be_cool,
            TAssert(YES, @"behave as expected");
        )
    )
)

Describe(NSDictionary,
    When(newly_created,
        It(should_have_no_objects,
            TAssert(YES, @"behave as expected");
        )
    )
)


int main(int argc, char *argv[]) {
    @autoreleasepool {
        [Test performTests];
    }
}