Acid tests should check bytecode too

[ionelmc]

The tests should verify that the pep8ized file generates the same bytecode as the original file.

There should be some sort of smart comparison because line numbers should not be compared.

I think is very important to verify that this tool doesn't actually change the code.

"Correct some non-idiomatic Python code." is mentioned in the readme but no details on what corrections are made ? This should be disabled for the bytecode match tests if it does code reductions or optimizations.

[myint]

I explored bytecode comparison when I first wrote the acid tests. I gave up on it once I found that things like has_key() and in didn't collapse into the same bytecode. But since autopep8 is now doing things a bit more complicated like shortening lines, it might be worth doing what you suggest. I suppose we would need to disable everything except whitespace, indentation, and line length changes.

By the way, the idiomatic changes I mention are basically the things 2to3 -f idioms fixes.

[myint]

See 8631ecb.

[myint]

I should probably do a recursive comparison of the code object rather than using dis. My current implementation with dis is basically just checking the top-level bytecode.

[myint]

For the most part, this works well. But sometimes the same code section generates different, but equivalent, bytecode representations. For example

16 LOAD_CONST             338 ((('catalogue', '0001_initial'), ('customer', '0001_initial'), ('partner', '0001_initial'), ('address', '0001_initial')))

versus

16 LOAD_CONST               1 ('catalogue')
19 LOAD_CONST               2 ('0001_initial')
22 BUILD_TUPLE              2
25 LOAD_CONST               3 ('customer')
28 LOAD_CONST               2 ('0001_initial')
31 BUILD_TUPLE              2
34 LOAD_CONST               4 ('partner')
37 LOAD_CONST               2 ('0001_initial')
40 BUILD_TUPLE              2
43 LOAD_CONST               5 ('address')
46 LOAD_CONST               2 ('0001_initial')
49 BUILD_TUPLE              2
52 BUILD_TUPLE              4

[myint]

Comparing the AST works better.