Pods/Expecta/src/matchers/EXPMatchers+beginWith.m
#import "EXPMatchers+beginWith.h"

EXPMatcherImplementationBegin(beginWith, (id expected)) {
  BOOL actualIsNil = (actual == nil);
  BOOL expectedIsNil = (expected == nil);
  //This condition allows the comparison of an immutable string or ordered collection to the mutable type of the same
  BOOL actualAndExpectedAreCompatible = (([actual isKindOfClass:[NSString class]] && [expected isKindOfClass:[NSString class]])
                                         || ([actual isKindOfClass:[NSArray class]] && [expected isKindOfClass:[NSArray class]])
                                         || ([actual isKindOfClass:[NSOrderedSet class]] && [expected isKindOfClass:[NSOrderedSet class]]));
  
  prerequisite(^BOOL {
    return actualAndExpectedAreCompatible;
  });
  
  match(^BOOL {
    if ([actual isKindOfClass:[NSString class]]) {
      return [actual hasPrefix:expected];
    } else if ([actual isKindOfClass:[NSArray class]]) {
      if ([expected count] > [actual count] || [expected count] == 0) {
        return NO;
      }
      NSArray *subArray = [actual subarrayWithRange:NSMakeRange(0, [expected count])];
      return [subArray isEqualToArray:expected];
    } else {
      if ([expected count] > [actual count] || [expected count] == 0) {
        return NO;
      }
      
      NSOrderedSet *subset = [NSOrderedSet orderedSetWithOrderedSet:actual range:NSMakeRange(0, [expected count]) copyItems:NO];
      return [subset isEqualToOrderedSet:expected];
    }
  });
  
  failureMessageForTo(^NSString *{
    if (actualIsNil) return @"the object is nil/null";
    if (expectedIsNil) return @"the expected value is nil/null";
    if (!actualAndExpectedAreCompatible) return [NSString stringWithFormat:@"%@ and %@ are not instances of one of %@, %@, or %@", EXPDescribeObject(actual), EXPDescribeObject(expected), [NSString class], [NSArray class], [NSOrderedSet class]];
    return [NSString stringWithFormat:@"expected: %@ to begin with %@", EXPDescribeObject(actual), EXPDescribeObject(expected)];
  });
  
  failureMessageForNotTo(^NSString *{
    if (actualIsNil) return @"the object is nil/null";
    if (expectedIsNil) return @"the expected value is nil/null";
    if (!actualAndExpectedAreCompatible) return [NSString stringWithFormat:@"%@ and %@ are not instances of one of %@, %@, or %@", EXPDescribeObject(actual), EXPDescribeObject(expected), [NSString class], [NSArray class], [NSOrderedSet class]];
    
    return [NSString stringWithFormat:@"expected: %@ not to begin with %@", EXPDescribeObject(actual), EXPDescribeObject(expected)];
  });
}
EXPMatcherImplementationEnd
