"""Base test case class for coverage testing.""" import glob, imp, os, random, shlex, shutil, sys, tempfile, textwrap import coverage from coverage.backward import sorted, StringIO # pylint: disable=W0622 from coverage.backward import to_bytes from backtest import run_command from backunittest import TestCase class Tee(object): """A file-like that writes to all the file-likes it has.""" def __init__(self, *files): """Make a Tee that writes to all the files in `files.`""" self._files = files if hasattr(files[0], "encoding"): self.encoding = files[0].encoding def write(self, data): """Write `data` to all the files.""" for f in self._files: f.write(data) # Status returns for the command line. OK, ERR = 0, 1 class CoverageTest(TestCase): """A base class for Coverage test cases.""" run_in_temp_dir = True def setUp(self): # Tell newer unittest implementations to print long helpful messages. self.longMessage = True # tearDown will restore the original sys.path self.old_syspath = sys.path[:] if self.run_in_temp_dir: # Create a temporary directory. self.noise = str(random.random())[2:] self.temp_root = os.path.join(tempfile.gettempdir(), 'test_cover') self.temp_dir = os.path.join(self.temp_root, self.noise) os.makedirs(self.temp_dir) self.old_dir = os.getcwd() os.chdir(self.temp_dir) # Modules should be importable from this temp directory. sys.path.insert(0, '') # Keep a counter to make every call to check_coverage unique. self.n = 0 # Record environment variables that we changed with set_environ. self.environ_undos = {} # Capture stdout and stderr so we can examine them in tests. # nose keeps stdout from littering the screen, so we can safely Tee it, # but it doesn't capture stderr, so we don't want to Tee stderr to the # real stderr, since it will interfere with our nice field of dots. self.old_stdout = sys.stdout self.captured_stdout = StringIO() sys.stdout = Tee(sys.stdout, self.captured_stdout) self.old_stderr = sys.stderr self.captured_stderr = StringIO() sys.stderr = self.captured_stderr # Record sys.modules here so we can restore it in tearDown. self.old_modules = dict(sys.modules) def tearDown(self): # Restore the original sys.path. sys.path = self.old_syspath if self.run_in_temp_dir: # Get rid of the temporary directory. os.chdir(self.old_dir) shutil.rmtree(self.temp_root) # Restore the environment. self.undo_environ() # Restore stdout and stderr sys.stdout = self.old_stdout sys.stderr = self.old_stderr self.clean_modules() def clean_modules(self): """Remove any new modules imported during the test run. This lets us import the same source files for more than one test. """ for m in [m for m in sys.modules if m not in self.old_modules]: del sys.modules[m] def set_environ(self, name, value): """Set an environment variable `name` to be `value`. The environment variable is set, and record is kept that it was set, so that `tearDown` can restore its original value. """ if name not in self.environ_undos: self.environ_undos[name] = os.environ.get(name) os.environ[name] = value def original_environ(self, name, if_missing=None): """The environment variable `name` from when the test started.""" if name in self.environ_undos: ret = self.environ_undos[name] else: ret = os.environ.get(name) if ret is None: ret = if_missing return ret def undo_environ(self): """Undo all the changes made by `set_environ`.""" for name, value in self.environ_undos.items(): if value is None: del os.environ[name] else: os.environ[name] = value def stdout(self): """Return the data written to stdout during the test.""" return self.captured_stdout.getvalue() def stderr(self): """Return the data written to stderr during the test.""" return self.captured_stderr.getvalue() def make_file(self, filename, text="", newline=None): """Create a temp file. `filename` is the path to the file, including directories if desired, and `text` is the content. If `newline` is provided, it is a string that will be used as the line endings in the created file. Returns the path to the file. """ # Tests that call `make_file` should be run in a temp environment. assert self.run_in_temp_dir text = textwrap.dedent(text) if newline: text = text.replace("\n", newline) # Make sure the directories are available. dirs, _ = os.path.split(filename) if dirs and not os.path.exists(dirs): os.makedirs(dirs) # Create the file. f = open(filename, 'wb') try: f.write(to_bytes(text)) finally: f.close() return filename def clean_local_file_imports(self): """Clean up the results of calls to `import_local_file`. Use this if you need to `import_local_file` the same file twice in one test. """ # So that we can re-import files, clean them out first. self.clean_modules() # Also have to clean out the .pyc file, since the timestamp # resolution is only one second, a changed file might not be # picked up. for pyc in glob.glob('*.pyc'): os.remove(pyc) if os.path.exists("__pycache__"): shutil.rmtree("__pycache__") def import_local_file(self, modname): """Import a local file as a module. Opens a file in the current directory named `modname`.py, imports it as `modname`, and returns the module object. """ modfile = modname + '.py' f = open(modfile, 'r') for suff in imp.get_suffixes(): if suff[0] == '.py': break try: # pylint: disable=W0631 # (Using possibly undefined loop variable 'suff') mod = imp.load_module(modname, f, modfile, suff) finally: f.close() return mod def get_module_name(self): """Return the module name to use for this test run.""" # We append self.n because otherwise two calls in one test will use the # same filename and whether the test works or not depends on the # timestamps in the .pyc file, so it becomes random whether the second # call will use the compiled version of the first call's code or not! modname = 'coverage_test_' + self.noise + str(self.n) self.n += 1 return modname # Map chars to numbers for arcz_to_arcs _arcz_map = {'.': -1} _arcz_map.update(dict([(c, ord(c)-ord('0')) for c in '123456789'])) _arcz_map.update(dict( [(c, 10+ord(c)-ord('A')) for c in 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'] )) def arcz_to_arcs(self, arcz): """Convert a compact textual representation of arcs to a list of pairs. The text has space-separated pairs of letters. Period is -1, 1-9 are 1-9, A-Z are 10 through 36. The resulting list is sorted regardless of the order of the input pairs. ".1 12 2." --> [(-1,1), (1,2), (2,-1)] Minus signs can be included in the pairs: "-11, 12, 2-5" --> [(-1,1), (1,2), (2,-5)] """ arcs = [] for pair in arcz.split(): asgn = bsgn = 1 if len(pair) == 2: a,b = pair else: assert len(pair) == 3 if pair[0] == '-': _,a,b = pair asgn = -1 else: assert pair[1] == '-' a,_,b = pair bsgn = -1 arcs.append((asgn*self._arcz_map[a], bsgn*self._arcz_map[b])) return sorted(arcs) def assertEqualArcs(self, a1, a2, msg=None): """Assert that the arc lists `a1` and `a2` are equal.""" # Make them into multi-line strings so we can see what's going wrong. s1 = "\n".join([repr(a) for a in a1]) + "\n" s2 = "\n".join([repr(a) for a in a2]) + "\n" self.assertMultiLineEqual(s1, s2, msg) def check_coverage(self, text, lines=None, missing="", report="", excludes=None, partials="", arcz=None, arcz_missing="", arcz_unpredicted=""): """Check the coverage measurement of `text`. The source `text` is run and measured. `lines` are the line numbers that are executable, or a list of possible line numbers, any of which could match. `missing` are the lines not executed, `excludes` are regexes to match against for excluding lines, and `report` is the text of the measurement report. For arc measurement, `arcz` is a string that can be decoded into arcs in the code (see `arcz_to_arcs` for the encoding scheme), `arcz_missing` are the arcs that are not executed, and `arcs_unpredicted` are the arcs executed in the code, but not deducible from the code. """ # We write the code into a file so that we can import it. # Coverage wants to deal with things as modules with file names. modname = self.get_module_name() self.make_file(modname+".py", text) arcs = arcs_missing = arcs_unpredicted = None if arcz is not None: arcs = self.arcz_to_arcs(arcz) arcs_missing = self.arcz_to_arcs(arcz_missing or "") arcs_unpredicted = self.arcz_to_arcs(arcz_unpredicted or "") # Start up Coverage. cov = coverage.coverage(branch=(arcs_missing is not None)) cov.erase() for exc in excludes or []: cov.exclude(exc) for par in partials or []: cov.exclude(par, which='partial') cov.start() try: # pragma: recursive coverage # Import the python file, executing it. mod = self.import_local_file(modname) finally: # pragma: recursive coverage # Stop Coverage. cov.stop() # Clean up our side effects del sys.modules[modname] # Get the analysis results, and check that they are right. analysis = cov._analyze(mod) if lines is not None: if type(lines[0]) == type(1): # lines is just a list of numbers, it must match the statements # found in the code. self.assertEqual(analysis.statements, lines) else: # lines is a list of possible line number lists, one of them # must match. for line_list in lines: if analysis.statements == line_list: break else: self.fail("None of the lines choices matched %r" % analysis.statements ) if type(missing) == type(""): self.assertEqual(analysis.missing_formatted(), missing) else: for missing_list in missing: if analysis.missing_formatted() == missing_list: break else: self.fail("None of the missing choices matched %r" % analysis.missing_formatted() ) if arcs is not None: self.assertEqualArcs( analysis.arc_possibilities(), arcs, "Possible arcs differ" ) if arcs_missing is not None: self.assertEqualArcs( analysis.arcs_missing(), arcs_missing, "Missing arcs differ" ) if arcs_unpredicted is not None: self.assertEqualArcs( analysis.arcs_unpredicted(), arcs_unpredicted, "Unpredicted arcs differ" ) if report: frep = StringIO() cov.report(mod, file=frep) rep = " ".join(frep.getvalue().split("\n")[2].split()[1:]) self.assertEqual(report, rep) def nice_file(self, *fparts): """Canonicalize the filename composed of the parts in `fparts`.""" fname = os.path.join(*fparts) return os.path.normcase(os.path.abspath(os.path.realpath(fname))) def assert_same_files(self, flist1, flist2): """Assert that `flist1` and `flist2` are the same set of file names.""" flist1_nice = [self.nice_file(f) for f in flist1] flist2_nice = [self.nice_file(f) for f in flist2] self.assertSameElements(flist1_nice, flist2_nice) def assert_exists(self, fname): """Assert that `fname` is a file that exists.""" msg = "File %r should exist" % fname self.assert_(os.path.exists(fname), msg) def assert_doesnt_exist(self, fname): """Assert that `fname` is a file that doesn't exist.""" msg = "File %r shouldn't exist" % fname self.assert_(not os.path.exists(fname), msg) def command_line(self, args, ret=OK, _covpkg=None): """Run `args` through the command line. Use this when you want to run the full coverage machinery, but in the current process. Exceptions may be thrown from deep in the code. Asserts that `ret` is returned by `CoverageScript.command_line`. Compare with `run_command`. Returns None. """ script = coverage.CoverageScript(_covpkg=_covpkg) ret_actual = script.command_line(shlex.split(args)) self.assertEqual(ret_actual, ret) def run_command(self, cmd): """Run the command-line `cmd` in a subprocess, and print its output. Use this when you need to test the process behavior of coverage. Compare with `command_line`. Returns the process' stdout text. """ _, output = self.run_command_status(cmd) return output def run_command_status(self, cmd, status=0): """Run the command-line `cmd` in a subprocess, and print its output. Use this when you need to test the process behavior of coverage. Compare with `command_line`. Returns a pair: the process' exit status and stdout text. The `status` argument is returned as the status on older Pythons where we can't get the actual exit status of the process. """ # Add our test modules directory to PYTHONPATH. I'm sure there's too # much path munging here, but... here = os.path.dirname(self.nice_file(coverage.__file__, "..")) testmods = self.nice_file(here, 'test/modules') zipfile = self.nice_file(here, 'test/zipmods.zip') pypath = os.getenv('PYTHONPATH', '') if pypath: pypath += os.pathsep pypath += testmods + os.pathsep + zipfile self.set_environ('PYTHONPATH', pypath) status, output = run_command(cmd, status=status) print(output) return status, output