#import "NSString+Additions.h" @implementation NSString (Additions) - (BOOL)isNotEmpty { return [self length] > 0; } @end - (void)test_Additions_isNotEmpty { NSString *string; string = @"foo"; XCTAssertTrue ([string isNotEmpty], @"長さを持った文字列はTrueを返す"); string = @""; XCTAssertFalse([string isNotEmpty], @"長さが0の文字列はFalseを返す"); string = nil; XCTAssertFalse([string isNotEmpty], @"nilに対しては(言語仕様上)Falseを返す