comparison contrib/import-checker.py @ 26965:1fa66d3ad28d

import-checker: reset context to verify convention in function scope

I got the following error by rewriting hgweb/webcommands.py to use
absolute_import. It is false-positive because the import line appears in
"help" function:

  hgweb/webcommands.py:1297: higher-level import should come first: mercurial

This patch makes the import checker aware of the function scope and apply
rules recursively.

26964:5abba2c92da3

#!/usr/bin/env python

import ast
import os
import sys

# Import a minimal set of stdlib modules needed for list_stdlib_modules()
# to work when run from a virtualenv.  The modules were chosen empirically

                for n in node.names:
                    if n.name == 'absolute_import':
                        return True

    return False

def dotted_name_of_path(path, trimpure=False):
    """Given a relative path to a source file, return its dotted module name.

    >>> dotted_name_of_path('mercurial/error.py')

    if absolute:
        return verify_modern_convention(module, root)
    else:
        return verify_stdlib_on_own_line(root)

def verify_modern_convention(module, root):
    """Verify a file conforms to the modern import convention rules.

    The rules of the modern convention are:

    * Ordering is stdlib followed by local imports. Each group is lexically

    # The last name to be imported (for sorting).
    lastname = None
    # Relative import levels encountered so far.
    seenlevels = set()

    for node in ast.walk(root):
        def msg(fmt, *args):
            return (fmt % args, node.lineno)
        if isinstance(node, ast.Import):
            # Disallow "import foo, bar" and require separate imports
            # for each module.
            if len(node.names) > 1:
                yield msg('multiple imported names: %s',
                          ', '.join(n.name for n in node.names))

            name = node.names[0].name
            asname = node.names[0].asname

            # Ignore sorting rules on imports inside blocks.
            if node.col_offset == 0:
                if lastname and name < lastname:
                    yield msg('imports not lexically sorted: %s < %s',
                              name, lastname)

                lastname = name

            # stdlib imports should be before local imports.
            stdlib = name in stdlib_modules
            if stdlib and seenlocal and node.col_offset == 0:
                yield msg('stdlib import follows local import: %s', name)

            if not stdlib:
                seenlocal = True

                else:
                    seenlocal = True

            # Direct symbol import is only allowed from certain modules and
            # must occur before non-symbol imports.
            if node.module and node.col_offset == 0:
                if fullname not in allowsymbolimports:
                    yield msg('direct symbol import from %s', fullname)

                if seennonsymbolrelative:
                    yield msg('symbol import follows non-symbol import: %s',

            if not node.module:
                assert node.level
                seennonsymbolrelative = True

                # Only allow 1 group per level.
                if node.level in seenlevels and node.col_offset == 0:
                    yield msg('multiple "from %s import" statements',
                              '.' * node.level)

                # Higher-level groups come before lower-level groups.
                if any(node.level > l for l in seenlevels):

26965:1fa66d3ad28d

#!/usr/bin/env python

import ast
import collections
import os
import sys

# Import a minimal set of stdlib modules needed for list_stdlib_modules()
# to work when run from a virtualenv.  The modules were chosen empirically

                for n in node.names:
                    if n.name == 'absolute_import':
                        return True

    return False

def walklocal(root):
    """Recursively yield all descendant nodes but not in a different scope"""
    todo = collections.deque(ast.iter_child_nodes(root))
    yield root, False
    while todo:
        node = todo.popleft()
        newscope = isinstance(node, ast.FunctionDef)
        if not newscope:
            todo.extend(ast.iter_child_nodes(node))
        yield node, newscope

def dotted_name_of_path(path, trimpure=False):
    """Given a relative path to a source file, return its dotted module name.

    >>> dotted_name_of_path('mercurial/error.py')

    if absolute:
        return verify_modern_convention(module, root)
    else:
        return verify_stdlib_on_own_line(root)

def verify_modern_convention(module, root, root_col_offset=0):
    """Verify a file conforms to the modern import convention rules.

    The rules of the modern convention are:

    * Ordering is stdlib followed by local imports. Each group is lexically

    # The last name to be imported (for sorting).
    lastname = None
    # Relative import levels encountered so far.
    seenlevels = set()

    for node, newscope in walklocal(root):
        def msg(fmt, *args):
            return (fmt % args, node.lineno)
        if newscope:
            # Check for local imports in function
            for r in verify_modern_convention(module, node,
                                              node.col_offset + 4):
                yield r
        elif isinstance(node, ast.Import):
            # Disallow "import foo, bar" and require separate imports
            # for each module.
            if len(node.names) > 1:
                yield msg('multiple imported names: %s',
                          ', '.join(n.name for n in node.names))

            name = node.names[0].name
            asname = node.names[0].asname

            # Ignore sorting rules on imports inside blocks.
            if node.col_offset == root_col_offset:
                if lastname and name < lastname:
                    yield msg('imports not lexically sorted: %s < %s',
                              name, lastname)

                lastname = name

            # stdlib imports should be before local imports.
            stdlib = name in stdlib_modules
            if stdlib and seenlocal and node.col_offset == root_col_offset:
                yield msg('stdlib import follows local import: %s', name)

            if not stdlib:
                seenlocal = True

                else:
                    seenlocal = True

            # Direct symbol import is only allowed from certain modules and
            # must occur before non-symbol imports.
            if node.module and node.col_offset == root_col_offset:
                if fullname not in allowsymbolimports:
                    yield msg('direct symbol import from %s', fullname)

                if seennonsymbolrelative:
                    yield msg('symbol import follows non-symbol import: %s',

            if not node.module:
                assert node.level
                seennonsymbolrelative = True

                # Only allow 1 group per level.
                if (node.level in seenlevels
                    and node.col_offset == root_col_offset):
                    yield msg('multiple "from %s import" statements',
                              '.' * node.level)

                # Higher-level groups come before lower-level groups.
                if any(node.level > l for l in seenlevels):