         ParserTests.fileManager.fileExists(atPath: path, isDirectory: &isDirectory)
         return isDirectory.boolValue
     }
+    
+    func parse(file: String) throws {
+        let fileStream = ANTLRFileStream(file)
+        let lexer = Swift3Lexer(fileStream)
+        let tokenStream = CommonTokenStream(lexer)
+        let parser = try Swift3Parser(tokenStream)
+        try parser.top_level()
+    }
+
 }

    
    static func ensure(folderAt path: String) {
        if !ParserTests.fileManager.fileExists(atPath: path) {
            try! ParserTests.fileManager.createDirectory(atPath: path, withIntermediateDirectories: false, attributes: nil)
        }
    }
    

    
    fileprivate static let ResourceURL = "https://github.com/hanjoes/antlr4.git"
    
    func testParsingWithNoError() throws {
        let inputFiles = ParserTests.findAllSwiftFiles(under: ParserTests.initializedRepoDir)
        _ = try inputFiles.map {
            inputFile in
            print("handling \(inputFile)")
            let fileStream = ANTLRFileStream(inputFile)
            let lexer = Swift3Lexer(fileStream)
            let tokenStream = CommonTokenStream(lexer)
            let parser = try Swift3Parser(tokenStream)
            try parser.top_level()
        }
    }
    
}
