blob: f0e043b91a7b8914cb7bda063b86c408ada22ef4 [file] [log] [blame]
"""Miscellaneous stuff for Coverage."""
import errno
import hashlib
import inspect
import os
import sys
from coverage.backward import string_class, to_bytes
def nice_pair(pair):
"""Make a nice string representation of a pair of numbers.
If the numbers are equal, just return the number, otherwise return the pair
with a dash between them, indicating the range.
"""
start, end = pair
if start == end:
return "%d" % start
else:
return "%d-%d" % (start, end)
def format_lines(statements, lines):
"""Nicely format a list of line numbers.
Format a list of line numbers for printing by coalescing groups of lines as
long as the lines represent consecutive statements. This will coalesce
even if there are gaps between statements.
For example, if `statements` is [1,2,3,4,5,10,11,12,13,14] and
`lines` is [1,2,5,10,11,13,14] then the result will be "1-2, 5-11, 13-14".
"""
pairs = []
i = 0
j = 0
start = None
statements = sorted(statements)
lines = sorted(lines)
while i < len(statements) and j < len(lines):
if statements[i] == lines[j]:
if start == None:
start = lines[j]
end = lines[j]
j += 1
elif start:
pairs.append((start, end))
start = None
i += 1
if start:
pairs.append((start, end))
ret = ', '.join(map(nice_pair, pairs))
return ret
def short_stack(): # pragma: debugging
"""Return a string summarizing the call stack."""
stack = inspect.stack()[:0:-1]
return "\n".join("%30s : %s @%d" % (t[3],t[1],t[2]) for t in stack)
def expensive(fn):
"""A decorator to cache the result of an expensive operation.
Only applies to methods with no arguments.
"""
attr = "_cache_" + fn.__name__
def _wrapped(self):
"""Inner fn that checks the cache."""
if not hasattr(self, attr):
setattr(self, attr, fn(self))
return getattr(self, attr)
return _wrapped
def bool_or_none(b):
"""Return bool(b), but preserve None."""
if b is None:
return None
else:
return bool(b)
def join_regex(regexes):
"""Combine a list of regexes into one that matches any of them."""
return "|".join("(?:%s)" % r for r in regexes)
def file_be_gone(path):
"""Remove a file, and don't get annoyed if it doesn't exist."""
try:
os.remove(path)
except OSError as e:
if e.errno != errno.ENOENT:
raise
class Hasher(object):
"""Hashes Python data into md5."""
def __init__(self):
self.md5 = hashlib.md5()
def update(self, v):
"""Add `v` to the hash, recursively if needed."""
self.md5.update(to_bytes(str(type(v))))
if isinstance(v, string_class):
self.md5.update(to_bytes(v))
elif v is None:
pass
elif isinstance(v, (int, float)):
self.md5.update(to_bytes(str(v)))
elif isinstance(v, (tuple, list)):
for e in v:
self.update(e)
elif isinstance(v, dict):
keys = v.keys()
for k in sorted(keys):
self.update(k)
self.update(v[k])
else:
for k in dir(v):
if k.startswith('__'):
continue
a = getattr(v, k)
if inspect.isroutine(a):
continue
self.update(k)
self.update(a)
def hexdigest(self):
"""Retrieve the hex digest of the hash."""
return self.md5.hexdigest()
def overrides(obj, method_name, base_class):
"""Does `obj` override the `method_name` it got from `base_class`?
Determine if `obj` implements the method called `method_name`, which it
inherited from `base_class`.
Returns a boolean.
"""
klass = obj.__class__
klass_func = getattr(klass, method_name)
base_func = getattr(base_class, method_name)
# Python 2/3 compatibility: Python 2 returns an instancemethod object, the
# function is the .im_func attribute. Python 3 returns a plain function
# object already.
if sys.version_info < (3, 0):
klass_func = klass_func.im_func
base_func = base_func.im_func
return klass_func is not base_func
class CoverageException(Exception):
"""An exception specific to Coverage."""
pass
class NoSource(CoverageException):
"""We couldn't find the source for a module."""
pass
class NoCode(NoSource):
"""We couldn't find any code at all."""
pass
class NotPython(CoverageException):
"""A source file turned out not to be parsable Python."""
pass
class ExceptionDuringRun(CoverageException):
"""An exception happened while running customer code.
Construct it with three arguments, the values from `sys.exc_info`.
"""
pass