Incorrectly generated if-goto code can pass both the BasicLoop and FibonacciSeries tests, and the error will not be caught until the FunctionCalls/FibonacciElement test.
The old versions of the tests only checked if-goto behavior for positive and zero arguments.
This new version of the FibonacciSeries test checks for negative arguments.
Download this file into your nand2tetris/projects/08/ProgramFlow/FibonacciSeries directory.
The FibonacciSeries.tst and FibonacciSeries.cmp files are unchanged.