Merge 5ba9965103 into 20209f691b

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())