Open source check-indent to auto-yelpdent.

README.md

@@ -23,6 +23,7 @@ Add this to your `.pre-commit-config.yaml`
 
 ### Hooks available
 
+- `auto-indent` - Checks and fixes indentation of function calls.
 - `autopep8-wrapper` - Runs autopep8 over python source.
     - Ignore PEP 8 violation types with `args: ['-i', '--ignore=E000,...']` or
       through configuration of the `[pep8]` section in setup.cfg / tox.ini.

hooks.yaml

@@ -1,3 +1,9 @@
+-   id: auto-indent
+    name: Check and fix indentation
+    language: python
+    entry: auto-indent
+    description: "Checks and fixes indentation of things like parameters and arguments."
+    files: \.py$
 -   id: autopep8-wrapper
     name: autopep8 wrapper
     description: "Runs autopep8 over python source.  If you configure additional arguments you'll want to at least include -i."

pre_commit_hooks/auto_indent.py

@@ -0,0 +1,183 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import
+from __future__ import print_function
+
+import argparse
+import ast
+import io
+import re
+import textwrap
+import traceback
+from operator import itemgetter
+
+
+RETURN_CODE = dict(
+    no_change=0,
+    fixed_file=1,
+    syntax_error=2,
+)
+
+
+class IndentNodeVisitor(ast.NodeVisitor):
+
+    def __init__(self):
+        self.lines = []
+
+    def visit_Call(self, node):
+        args = list(node.args)
+
+        if node.keywords:
+            args.extend([keyword.value for keyword in node.keywords])
+
+        if node.starargs:
+            args.append(node.starargs)
+
+        if node.kwargs:
+            args.append(node.kwargs)
+
+        try:
+            if args and args[0].lineno == node.lineno:
+                for arg in args:
+                    if arg.lineno != node.lineno:
+                        self.lines.append({
+                            'line': node.lineno,
+                            'nextline': arg.lineno,
+                            'column': args[0].col_offset,
+                        })
+                        break
+        except AttributeError:
+            # Python 3.3 is not supported because line numbers were
+            # removed from arg objects (compared to Python 2.7 and Python 3.4):
+            # https://docs.python.org/3.3/library/ast.html
+            pass
+        finally:
+            self.generic_visit(node)
+
+    def visit_ClassDef(self, node):
+        if node.bases and node.bases[0].lineno != node.lineno:
+            self.generic_visit(node)
+            return
+
+        for base in node.bases:
+            if base.lineno != node.lineno:
+                self.lines.append({
+                    'line': node.lineno,
+                    'nextline': base.lineno,
+                    'column': node.bases[0].col_offset,
+                })
+
+                break
+
+        self.generic_visit(node)
+
+    def visit_FunctionDef(self, node):
+        try:
+            if node.args.args and node.args.args[0].lineno != node.lineno:
+                self.generic_visit(node)
+                return
+
+            for arg in node.args.args:
+                if arg.lineno != node.lineno:
+                    self.lines.append({
+                        'line': node.lineno,
+                        'nextline': arg.lineno,
+                        'column': node.args.args[0].col_offset,
+                    })
+
+                    break
+        except AttributeError:
+            # Python 3.3 is not supported because line numbers were
+            # removed from arg objects (compared to Python 2.7 and Python 3.4):
+            # https://docs.python.org/3.3/library/ast.html
+            pass
+        finally:
+            self.generic_visit(node)
+
+
+def check_files(files):
+    rc = RETURN_CODE['no_change']
+
+    for fpath in files:
+        with open(fpath) as f:
+            source = f.read()
+
+            try:
+                tree = ast.parse(source, fpath)
+            except SyntaxError:
+                traceback.print_exc()
+                return RETURN_CODE['syntax_error']
+
+            visitor = IndentNodeVisitor()
+            visitor.visit(tree)
+
+            if visitor.lines:
+                rc = RETURN_CODE['fixed_file']
+                print('Fixing ' + fpath)
+                fix_lines(
+                    file_path=fpath,
+                    source_lines=source.split('\n'),
+                    line_data=visitor.lines,
+                )
+
+    return rc
+
+
+def fix_lines(file_path, source_lines, line_data):
+    line_data = sorted(line_data, key=itemgetter('line'))
+    last_lineno = None
+    same_line_adjustment = 0
+
+    for i, data in enumerate(line_data):
+        adjustment = 0
+        lineno = data['line'] + i - 1
+
+        if data['line'] == last_lineno:
+            adjustment = same_line_adjustment
+
+        start = 1 + source_lines[lineno].rfind(
+            '(',
+            0,
+            data['column'] + adjustment,
+        )
+
+        nextline = source_lines[data['nextline'] + i - 1]
+        indent = re.search('[ \t]*', nextline).group()
+        new_line = indent + source_lines[lineno][start:]
+
+        source_lines[lineno] = source_lines[lineno][:start]
+        source_lines.insert(lineno + 1, new_line)
+
+        with io.open(file_path, 'w') as f:
+            f.write(u'\n'.join(source_lines))
+
+        last_lineno = data['line']
+        same_line_adjustment = len(indent) - start
+
+
+def main(argv=None):
+    parser = argparse.ArgumentParser(
+        description=textwrap.dedent(
+            """
+            Checks that parameters and arguments to functions, classes,
+            and function calls are either all on the same line as the
+            corresponding function or class or that none are.
+
+            If it finds any violations, the offending parameters or arguments
+            will automatically be moved to a new line.
+
+            Return codes are:
+
+                0: no file change
+                1: file fixed
+                2: Python syntax error
+            """
+        )
+    )
+    parser.add_argument('filenames', nargs='*')
+    args = parser.parse_args(argv)
+
+    return check_files(args.filenames)
+
+
+if __name__ == '__main__':
+    exit(main())

testing/resources/auto_indent/file_with_acceptable_indentation

@@ -0,0 +1,62 @@
+# bad
+def foo(
+    a,
+    b,
+    c,
+    *args,
+    **kwargs
+):
+    pass
+
+# okay
+def bar():
+    pass
+
+# bad
+_ = foo(
+    1,
+    2,
+    3,
+    4,
+    e=5,
+    *[],
+    **{}
+)
+
+# okay
+_ = bar()
+
+# okay
+_ = foo(bar, baz, womp)
+
+# bad
+class baz(
+    object,
+    object,
+):
+    pass
+
+# okay
+class qux:
+    pass
+
+# bad
+_ = foo(
+    foo(
+        1 + foo(
+            1,  # trickier
+            2,
+            3,
+        ),
+        4,
+        5,
+    ),
+    6,
+    7,
+)
+
+# bad
+_ = '(wow)'.foo(
+    no,
+    way,
+)

testing/resources/auto_indent/file_with_bad_indentation

@@ -0,0 +1,55 @@
+# bad
+def foo(a,
+    b,
+    c,
+    *args,
+    **kwargs
+):
+    pass
+
+# okay
+def bar():
+    pass
+
+# bad
+_ = foo(1,
+    2,
+    3,
+    4,
+    e=5,
+    *[],
+    **{}
+)
+
+# okay
+_ = bar()
+
+# okay
+_ = foo(bar, baz, womp)
+
+# bad
+class baz(object,
+    object,
+):
+    pass
+
+# okay
+class qux:
+    pass
+
+# bad
+_ = foo(foo(1 + foo(1,  # trickier
+            2,
+            3,
+        ),
+        4,
+        5,
+    ),
+    6,
+    7,
+)
+
+# bad
+_ = '(wow)'.foo(no,
+    way,
+)

testing/resources/auto_indent/file_with_partial_indentation

@@ -0,0 +1,61 @@
+# bad
+def foo(a,
+    b,
+    c,
+    *args,
+    **kwargs
+):
+    pass
+
+# okay
+def bar():
+    pass
+
+# bad
+_ = foo(
+    1,
+    2,
+    3,
+    4,
+    e=5,
+    *[],
+    **{}
+)
+
+# okay
+_ = bar()
+
+# okay
+_ = foo(bar, baz, womp)
+
+# bad
+class baz(
+    object,
+    object,
+):
+    pass
+
+# okay
+class qux:
+    pass
+
+# bad
+_ = foo(
+    foo(
+        1 + foo(
+            1,  # trickier
+            2,
+            3,
+        ),
+        4,
+        5,
+    ),
+    6,
+    7,
+)
+
+# bad
+_ = '(wow)'.foo(
+    no,
+    way,
+)

testing/resources/auto_indent/syntax_error

@@ -0,0 +1,4 @@
+def foo(a,
+  b,
+)
+    pass

tests/auto_indent_test.py

@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import
+from __future__ import print_function
+
+import filecmp
+import os
+import sys
+from shutil import copyfile
+
+import pytest
+
+from pre_commit_hooks.auto_indent import main
+from pre_commit_hooks.auto_indent import RETURN_CODE
+from testing.util import get_resource_path
+
+
+def _has_ast_arg_lineno_support():
+    """Checks if AST has all the info necessary to auto indent.
+
+    Some Python implementations removed line numbers from AST arg objects and
+    as a result we can't automatically format function calls.
+    """
+    if sys.version_info.major == 3 and sys.version_info.minor == 3:
+        return False
+    elif sys.version_info.major == 3 and sys.version_info.minor == 2:
+        return False
+    else:
+        return True
+
+
+@pytest.mark.parametrize(
+    ('infile', 'expected_rc'),
+    (
+        ('file_with_acceptable_indentation', RETURN_CODE['no_change']),
+        ('syntax_error', RETURN_CODE['syntax_error']),
+    )
+)
+def test_check_indentation(infile, expected_rc):
+    in_path = get_resource_path(os.path.join('auto_indent', infile))
+    assert main([in_path]) == expected_rc
+
+
+@pytest.mark.skipif(not _has_ast_arg_lineno_support(), reason='See docstring.')
+def test_fix_bad_indentation(tmpdir):
+    in_path = get_resource_path(os.path.join(
+        'auto_indent',
+        'file_with_bad_indentation'
+    ))
+    expected_out_path = get_resource_path(os.path.join(
+        'auto_indent',
+        'file_with_acceptable_indentation'
+    ))
+    tmp_path = tmpdir.join('auto_indent').strpath
+    copyfile(in_path, tmp_path)
+
+    assert main([tmp_path]) == RETURN_CODE['fixed_file']
+    assert filecmp.cmp(tmp_path, expected_out_path)
+
+
+@pytest.mark.skipif(_has_ast_arg_lineno_support(), reason='See docstring.')
+def test_partial_fix_bad_indentation(tmpdir):
+    in_path = get_resource_path(os.path.join(
+        'auto_indent',
+        'file_with_bad_indentation'
+    ))
+    expected_out_path = get_resource_path(os.path.join(
+        'auto_indent',
+        'file_with_partial_indentation'
+    ))
+    tmp_path = tmpdir.join('auto_indent').strpath
+    copyfile(in_path, tmp_path)
+
+    assert main([tmp_path]) == RETURN_CODE['fixed_file']
+    assert filecmp.cmp(tmp_path, expected_out_path)

tox.ini

@@ -4,11 +4,14 @@ project = pre_commit_hooks
 envlist = py27,py33,py34,pypy,pypy3
 
 [testenv]
-deps = -rrequirements-dev.txt
+deps =
+    -rrequirements-dev.txt
+    ipdb
+    ipython
 passenv = HOME HOMEPATH PROGRAMDATA
 commands =
     coverage erase
-    coverage run -m pytest {posargs:tests}
+    coverage run -m pytest -s -rxs -vv {posargs:tests}
     coverage report --show-missing --fail-under 100
     pre-commit install -f --install-hooks
     pre-commit run --all-files