view contrib/hgfixes/fix_leftover_imports.py @ 19966:7985e3469f58 stable

largefiles: systematic testing of merges to/from largefiles

427ce5633c1c fixed one problem with update and added a test case for it. The
test coverage was thus insufficient before that.

To make sure we have good test coverage in this area we add systematic testing
of all cases of merges that may or may not change normal files to largefiles or
vice versa.

The tests shows some annoying extra merge prompts in some cases, but these
prompts are hard to avoid and they are now "safe" - they do not leave the
system in a confused inconsistent state.

"Fixer that translates some APIs ignored by the default 2to3 fixers."

# FIXME: This fixer has some ugly hacks. Its main design is based on that of
# fix_imports, from lib2to3. Unfortunately, the fix_imports framework only
# changes module names "without dots", meaning it won't work for some changes
# in the email module/package. Thus this fixer was born. I believe that with a
# bit more thinking, a more generic fixer can be implemented, but I'll leave
# that as future work.

from lib2to3.fixer_util import Name
from lib2to3.fixes import fix_imports

# This maps the old names to the new names. Note that a drawback of the current
# design is that the dictionary keys MUST have EXACTLY one dot (.) in them,
# otherwise things will break. (If you don't need a module hierarchy, you're
# better of just inherit from fix_imports and overriding the MAPPING dict.)

MAPPING = {'email.Utils': 'email.utils',
           'email.Errors': 'email.errors',
           'email.Header': 'email.header',
           'email.Parser': 'email.parser',
           'email.Encoders': 'email.encoders',
           'email.MIMEText': 'email.mime.text',
           'email.MIMEBase': 'email.mime.base',
           'email.Generator': 'email.generator',
           'email.MIMEMultipart': 'email.mime.multipart',
}

def alternates(members):
    return "(" + "|".join(map(repr, members)) + ")"

def build_pattern(mapping=MAPPING):
    packages = {}
    for key in mapping:
        # What we are doing here is the following: with dotted names, we'll
        # have something like package_name <trailer '.' module>. Then, we are
        # making a dictionary to copy this structure. For example, if
        # mapping={'A.B': 'a.b', 'A.C': 'a.c'}, it will generate the dictionary
        # {'A': ['b', 'c']} to, then, generate something like "A <trailer '.'
        # ('b' | 'c')".
        name = key.split('.')
        prefix = name[0]
        if prefix in packages:
            packages[prefix].append(name[1:][0])
        else:
            packages[prefix] = name[1:]

    mod_list = ' | '.join(["'%s' '.' ('%s')" %
        (key, "' | '".join(packages[key])) for key in packages])
    mod_list = '(' + mod_list + ' )'

    yield """name_import=import_name< 'import' module_name=dotted_name< %s > >
          """ % mod_list

    yield """name_import=import_name< 'import'
            multiple_imports=dotted_as_names< any*
            module_name=dotted_name< %s >
            any* >
            >""" % mod_list

    packs = ' | '.join(["'%s' trailer<'.' ('%s')>" % (key,
               "' | '".join(packages[key])) for key in packages])

    yield "power< package=(%s) trailer<'.' any > any* >" % packs

class FixLeftoverImports(fix_imports.FixImports):
    # We want to run this fixer after fix_import has run (this shouldn't matter
    # for hg, though, as setup3k prefers to run the default fixers first)
    mapping = MAPPING

    def build_pattern(self):
        return "|".join(build_pattern(self.mapping))

    def transform(self, node, results):
        # Mostly copied from fix_imports.py
        import_mod = results.get("module_name")
        if import_mod:
            try:
                mod_name = import_mod.value
            except AttributeError:
                # XXX: A hack to remove whitespace prefixes and suffixes
                mod_name = str(import_mod).strip()
            new_name = self.mapping[mod_name]
            import_mod.replace(Name(new_name, prefix=import_mod.prefix))
            if "name_import" in results:
                # If it's not a "from x import x, y" or "import x as y" import,
                # marked its usage to be replaced.
                self.replace[mod_name] = new_name
            if "multiple_imports" in results:
                # This is a nasty hack to fix multiple imports on a line (e.g.,
                # "import StringIO, urlparse"). The problem is that I can't
                # figure out an easy way to make a pattern recognize the keys of
                # MAPPING randomly sprinkled in an import statement.
                results = self.match(node)
                if results:
                    self.transform(node, results)
        else:
            # Replace usage of the module.
            # Now this is, mostly, a hack
            bare_name = results["package"][0]
            bare_name_text = ''.join(map(str, results['package'])).strip()
            new_name = self.replace.get(bare_name_text)
            prefix = results['package'][0].prefix
            if new_name:
                bare_name.replace(Name(new_name, prefix=prefix))
                results["package"][1].replace(Name(''))