Python code coverage for Lib/lib2to3/fixer_base.py

#	count	content
1	n/a	# Copyright 2006 Google, Inc. All Rights Reserved.
2	n/a	# Licensed to PSF under a Contributor Agreement.
3	n/a
4	n/a	"""Base class for fixers (optional, but recommended)."""
5	n/a
6	n/a	# Python imports
7	n/a	import itertools
8	n/a
9	n/a	# Local imports
10	n/a	from .patcomp import PatternCompiler
11	n/a	from . import pygram
12	n/a	from .fixer_util import does_tree_import
13	n/a
14	n/a	class BaseFix(object):
15	n/a
16	n/a	"""Optional base class for fixers.
17	n/a
18	n/a	The subclass name must be FixFooBar where FooBar is the result of
19	n/a	removing underscores and capitalizing the words of the fix name.
20	n/a	For example, the class name for a fixer named 'has_key' should be
21	n/a	FixHasKey.
22	n/a	"""
23	n/a
24	n/a	PATTERN = None # Most subclasses should override with a string literal
25	n/a	pattern = None # Compiled pattern, set by compile_pattern()
26	n/a	pattern_tree = None # Tree representation of the pattern
27	n/a	options = None # Options object passed to initializer
28	n/a	filename = None # The filename (set by set_filename)
29	n/a	numbers = itertools.count(1) # For new_name()
30	n/a	used_names = set() # A set of all used NAMEs
31	n/a	order = "post" # Does the fixer prefer pre- or post-order traversal
32	n/a	explicit = False # Is this ignored by refactor.py -f all?
33	n/a	run_order = 5 # Fixers will be sorted by run order before execution
34	n/a	# Lower numbers will be run first.
35	n/a	_accept_type = None # [Advanced and not public] This tells RefactoringTool
36	n/a	# which node type to accept when there's not a pattern.
37	n/a
38	n/a	keep_line_order = False # For the bottom matcher: match with the
39	n/a	# original line order
40	n/a	BM_compatible = False # Compatibility with the bottom matching
41	n/a	# module; every fixer should set this
42	n/a	# manually
43	n/a
44	n/a	# Shortcut for access to Python grammar symbols
45	n/a	syms = pygram.python_symbols
46	n/a
47	n/a	def __init__(self, options, log):
48	n/a	"""Initializer. Subclass may override.
49	n/a
50	n/a	Args:
51	n/a	options: a dict containing the options passed to RefactoringTool
52	n/a	that could be used to customize the fixer through the command line.
53	n/a	log: a list to append warnings and other messages to.
54	n/a	"""
55	n/a	self.options = options
56	n/a	self.log = log
57	n/a	self.compile_pattern()
58	n/a
59	n/a	def compile_pattern(self):
60	n/a	"""Compiles self.PATTERN into self.pattern.
61	n/a
62	n/a	Subclass may override if it doesn't want to use
63	n/a	self.{pattern,PATTERN} in .match().
64	n/a	"""
65	n/a	if self.PATTERN is not None:
66	n/a	PC = PatternCompiler()
67	n/a	self.pattern, self.pattern_tree = PC.compile_pattern(self.PATTERN,
68	n/a	with_tree=True)
69	n/a
70	n/a	def set_filename(self, filename):
71	n/a	"""Set the filename.
72	n/a
73	n/a	The main refactoring tool should call this.
74	n/a	"""
75	n/a	self.filename = filename
76	n/a
77	n/a	def match(self, node):
78	n/a	"""Returns match for a given parse tree node.
79	n/a
80	n/a	Should return a true or false object (not necessarily a bool).
81	n/a	It may return a non-empty dict of matching sub-nodes as
82	n/a	returned by a matching pattern.
83	n/a
84	n/a	Subclass may override.
85	n/a	"""
86	n/a	results = {"node": node}
87	n/a	return self.pattern.match(node, results) and results
88	n/a
89	n/a	def transform(self, node, results):
90	n/a	"""Returns the transformation for a given parse tree node.
91	n/a
92	n/a	Args:
93	n/a	node: the root of the parse tree that matched the fixer.
94	n/a	results: a dict mapping symbolic names to part of the match.
95	n/a
96	n/a	Returns:
97	n/a	None, or a node that is a modified copy of the
98	n/a	argument node. The node argument may also be modified in-place to
99	n/a	effect the same change.
100	n/a
101	n/a	Subclass must override.
102	n/a	"""
103	n/a	raise NotImplementedError()
104	n/a
105	n/a	def new_name(self, template="xxx_todo_changeme"):
106	n/a	"""Return a string suitable for use as an identifier
107	n/a
108	n/a	The new name is guaranteed not to conflict with other identifiers.
109	n/a	"""
110	n/a	name = template
111	n/a	while name in self.used_names:
112	n/a	name = template + str(next(self.numbers))
113	n/a	self.used_names.add(name)
114	n/a	return name
115	n/a
116	n/a	def log_message(self, message):
117	n/a	if self.first_log:
118	n/a	self.first_log = False
119	n/a	self.log.append("### In file %s ###" % self.filename)
120	n/a	self.log.append(message)
121	n/a
122	n/a	def cannot_convert(self, node, reason=None):
123	n/a	"""Warn the user that a given chunk of code is not valid Python 3,
124	n/a	but that it cannot be converted automatically.
125	n/a
126	n/a	First argument is the top-level node for the code in question.
127	n/a	Optional second argument is why it can't be converted.
128	n/a	"""
129	n/a	lineno = node.get_lineno()
130	n/a	for_output = node.clone()
131	n/a	for_output.prefix = ""
132	n/a	msg = "Line %d: could not convert: %s"
133	n/a	self.log_message(msg % (lineno, for_output))
134	n/a	if reason:
135	n/a	self.log_message(reason)
136	n/a
137	n/a	def warning(self, node, reason):
138	n/a	"""Used for warning the user about possible uncertainty in the
139	n/a	translation.
140	n/a
141	n/a	First argument is the top-level node for the code in question.
142	n/a	Optional second argument is why it can't be converted.
143	n/a	"""
144	n/a	lineno = node.get_lineno()
145	n/a	self.log_message("Line %d: %s" % (lineno, reason))
146	n/a
147	n/a	def start_tree(self, tree, filename):
148	n/a	"""Some fixers need to maintain tree-wide state.
149	n/a	This method is called once, at the start of tree fix-up.
150	n/a
151	n/a	tree - the root node of the tree to be processed.
152	n/a	filename - the name of the file the tree came from.
153	n/a	"""
154	n/a	self.used_names = tree.used_names
155	n/a	self.set_filename(filename)
156	n/a	self.numbers = itertools.count(1)
157	n/a	self.first_log = True
158	n/a
159	n/a	def finish_tree(self, tree, filename):
160	n/a	"""Some fixers need to maintain tree-wide state.
161	n/a	This method is called once, at the conclusion of tree fix-up.
162	n/a
163	n/a	tree - the root node of the tree to be processed.
164	n/a	filename - the name of the file the tree came from.
165	n/a	"""
166	n/a	pass
167	n/a
168	n/a
169	n/a	class ConditionalFix(BaseFix):
170	n/a	""" Base class for fixers which not execute if an import is found. """
171	n/a
172	n/a	# This is the name of the import which, if found, will cause the test to be skipped
173	n/a	skip_on = None
174	n/a
175	n/a	def start_tree(self, *args):
176	n/a	super(ConditionalFix, self).start_tree(*args)
177	n/a	self._should_skip = None
178	n/a
179	n/a	def should_skip(self, node):
180	n/a	if self._should_skip is not None:
181	n/a	return self._should_skip
182	n/a	pkg = self.skip_on.split(".")
183	n/a	name = pkg[-1]
184	n/a	pkg = ".".join(pkg[:-1])
185	n/a	self._should_skip = does_tree_import(pkg, name, node)
186	n/a	return self._should_skip