[PATCH 6 of 8] import-checker: handle ast.parse SyntaxErrors

[Yuya Nishihara]

On Sun, 3 Apr 2016 11:12:16 -0700, Gregory Szorc wrote:
> On Thu, Mar 31, 2016 at 7:34 AM, Yuya Nishihara <yuya at tcha.org> wrote:
> > On Wed, 30 Mar 2016 04:24:06 -0500, timeless wrote:  
> > > # HG changeset patch
> > > # User timeless <timeless at mozdev.org>
> > > # Date 1459325470 0
> > > #      Wed Mar 30 08:11:10 2016 +0000
> > > # Node ID d8be8db8119d2d716ad9ddaaaa077cf278f6273c
> > > # Parent  54b962661f75e4a55c213c0eeb30f5d6024f7dbe
> > > import-checker: handle ast.parse SyntaxErrors
> > >
> > > diff --git a/contrib/import-checker.py b/contrib/import-checker.py
> > > --- a/contrib/import-checker.py
> > > +++ b/contrib/import-checker.py
> > > @@ -233,6 +233,13 @@
> > >
> > >  stdlib_modules = set(list_stdlib_modules())
> > >
> > > +def parse(source):
> > > +    """Wrapper around ast.parse()"""
> > > +    try:
> > > +        return ast.parse(source)
> > > +    except SyntaxError:
> > > +        return ast.parse("'SyntaxError'")  
> >
> > Doesn't it just bury a SyntaxError? I think it should be reported as an
> > error like other messages.
> >
> Yes, but this patch does get us import-checker.py support for Python 3
> without having to fix all syntax errors on Python 3 first.
> 
> We may want to establish a standalone test to verify ast parsing on all .py
> files (if we don't have one already). test-check-py3-compat.t does this,
> but only for Python 3. It seems like a useful test to have. I'm fine with
> only 1 test reporting ast/import errors, especially on Python 3 (otherwise
> we'd have to update multiple tests when addressing Python 3 compat).

I think it's good thing to catch the SyntaxError, but IMHO it should be
reported. Otherwise I would miss the error when running import-checker.py
manually.