Merge pull request #10903 from anntzer/py3testing

jklymak · web-flow · commit 0043d9a1e8ed · 2018-03-27T22:15:07.000-07:00
Py3fy testing machinery.
diff --git a/lib/matplotlib/testing/__init__.py b/lib/matplotlib/testing/__init__.py
@@ -10,13 +10,6 @@ def is_called_from_pytest():
     return getattr(mpl, '_called_from_pytest', False)
 
 
-def _copy_metadata(src_func, tgt_func):
-    """Replicates metadata of the function. Returns target function."""
-    functools.update_wrapper(tgt_func, src_func)
-    tgt_func.__wrapped__ = src_func  # Python2 compatibility.
-    return tgt_func
-
-
 def set_font_settings_for_testing():
     mpl.rcParams['font.family'] = 'DejaVu Sans'
     mpl.rcParams['text.hinting'] = False
diff --git a/lib/matplotlib/testing/compare.py b/lib/matplotlib/testing/compare.py
@@ -181,15 +181,14 @@ def __call__(self, orig, dest):
             # reported as a regular exception below).
             env.pop("DISPLAY", None)  # May already be unset.
             # Do not load any user options.
-            # `os.environ` needs native strings on Py2+Windows.
-            env[str("INKSCAPE_PROFILE_DIR")] = os.devnull
+            env["INKSCAPE_PROFILE_DIR"] = os.devnull
             # Old versions of Inkscape (0.48.3.1, used on Travis as of now)
             # seem to sometimes deadlock when stderr is redirected to a pipe,
             # so we redirect it to a temporary file instead.  This is not
             # necessary anymore as of Inkscape 0.92.1.
             self._stderr = TemporaryFile()
             self._proc = subprocess.Popen(
-                [str("inkscape"), "--without-gui", "--shell"],
+                ["inkscape", "--without-gui", "--shell"],
                 stdin=subprocess.PIPE, stdout=subprocess.PIPE,
                 stderr=self._stderr, env=env)
             if not self._read_to_prompt():
@@ -210,7 +209,7 @@ def fsencode(s):
             # slow solution (Inkscape uses `fgets` so it will always stop at a
             # newline).
             return make_external_conversion_command(lambda old, new: [
-                str('inkscape'), '-z', old, '--export-png', new])(orig, dest)
+                'inkscape', '-z', old, '--export-png', new])(orig, dest)
         self._proc.stdin.write(orig_b + b" --export-png=" + dest_b + b"\n")
         self._proc.stdin.flush()
         if not self._read_to_prompt():
@@ -329,8 +328,8 @@ def calculate_rms(expectedImage, actualImage):
     "Calculate the per-pixel errors, then compute the root mean square error."
     if expectedImage.shape != actualImage.shape:
         raise ImageComparisonFailure(
-            "Image sizes do not match expected size: {0} "
-            "actual size {1}".format(expectedImage.shape, actualImage.shape))
+            "Image sizes do not match expected size: {} "
+            "actual size {}".format(expectedImage.shape, actualImage.shape))
     # Convert to float to avoid overflowing finite integer types.
     return np.sqrt(((expectedImage - actualImage).astype(float) ** 2).mean())
 
@@ -361,7 +360,7 @@ def compare_images(expected, actual, tol, in_decorator=False):
     --------
     img1 = "./baseline/plot.png"
     img2 = "./output/plot.png"
-    compare_images( img1, img2, 0.001 ):
+    compare_images(img1, img2, 0.001):
 
     """
     if not os.path.exists(actual):
@@ -391,7 +390,7 @@ def compare_images(expected, actual, tol, in_decorator=False):
 
     diff_image = make_test_filename(actual, 'failed-diff')
 
-    if tol <= 0.0:
+    if tol <= 0:
         if np.array_equal(expectedImage, actualImage):
             return None
 
@@ -431,8 +430,8 @@ def save_diff_image(expected, actual, output):
     actualImage = np.array(actualImage).astype(float)
     if expectedImage.shape != actualImage.shape:
         raise ImageComparisonFailure(
-            "Image sizes do not match expected size: {0} "
-            "actual size {1}".format(expectedImage.shape, actualImage.shape))
+            "Image sizes do not match expected size: {} "
+            "actual size {}".format(expectedImage.shape, actualImage.shape))
     absDiffImage = np.abs(expectedImage - actualImage)
 
     # expand differences in luminance domain
diff --git a/lib/matplotlib/testing/decorators.py b/lib/matplotlib/testing/decorators.py
@@ -1,6 +1,5 @@
 from distutils.version import StrictVersion
 import functools
-import inspect
 import os
 from pathlib import Path
 import shutil
@@ -23,7 +22,7 @@
 from matplotlib import ft2font
 from matplotlib.testing.compare import (
     comparable_formats, compare_images, make_test_filename)
-from . import _copy_metadata, is_called_from_pytest
+from . import is_called_from_pytest
 from .exceptions import ImageComparisonFailure
 
 
@@ -250,9 +249,9 @@ def copy_baseline(self, baseline, extension):
         if os.path.exists(orig_expected_fname):
             shutil.copyfile(orig_expected_fname, expected_fname)
         else:
-            reason = ("Do not have baseline image {0} because this "
-                      "file does not exist: {1}".format(expected_fname,
-                                                        orig_expected_fname))
+            reason = ("Do not have baseline image {} because this "
+                      "file does not exist: {}".format(expected_fname,
+                                                       orig_expected_fname))
             raise ImageComparisonFailure(reason)
         return expected_fname
 
@@ -327,11 +326,12 @@ def __call__(self, func):
         self.delayed_init(func)
         import nose.tools
 
+        @functools.wraps(func)
         @nose.tools.with_setup(self.setup, self.teardown)
         def runner_wrapper():
             yield from self.nose_runner()
 
-        return _copy_metadata(func, runner_wrapper)
+        return runner_wrapper
 
 
 def _pytest_image_comparison(baseline_images, extensions, tol,
@@ -350,6 +350,7 @@ def _pytest_image_comparison(baseline_images, extensions, tol,
     extensions = map(_mark_xfail_if_format_is_uncomparable, extensions)
 
     def decorator(func):
+        @functools.wraps(func)
         # Parameter indirection; see docstring above and comment below.
         @pytest.mark.usefixtures('mpl_image_comparison_parameters')
         @pytest.mark.parametrize('extension', extensions)
@@ -379,8 +380,7 @@ def wrapper(*args, **kwargs):
             for idx, baseline in enumerate(baseline_images):
                 img.compare(idx, baseline, extension)
 
-        wrapper.__wrapped__ = func  # For Python 2.7.
-        return _copy_metadata(func, wrapper)
+        return wrapper
 
     return decorator
 
@@ -408,7 +408,7 @@ def image_comparison(baseline_images, extensions=None, tol=0,
     extensions : [ None | list ]
 
         If None, defaults to all supported extensions.
-        Otherwise, a list of extensions to test. For example ['png','pdf'].
+        Otherwise, a list of extensions to test, e.g. ``['png', 'pdf']``.
 
     tol : float, optional, default: 0
         The RMS threshold above which the test is considered failed.
@@ -464,10 +464,10 @@ def _image_directories(func):
         # FIXME: this won't work for nested packages in matplotlib.tests
         warnings.warn(
             'Test module run as script. Guessing baseline image locations.')
-        script_name = sys.argv[0]
-        basedir = os.path.abspath(os.path.dirname(script_name))
-        subdir = os.path.splitext(os.path.split(script_name)[1])[0]
+        module_path = Path(sys.argv[0]).resolve()
+        subdir = module_path.stem
     else:
+        module_path = Path(sys.modules[func.__module__].__file__)
         mods = module_name.split('.')
         if len(mods) >= 3:
             mods.pop(0)
@@ -486,50 +486,29 @@ def _image_directories(func):
                 "file (can be empty).".format(module_name))
         subdir = os.path.join(*mods)
 
-        import imp
-        def find_dotted_module(module_name, path=None):
-            """A version of imp which can handle dots in the module name.
-               As for imp.find_module(), the return value is a 3-element
-               tuple (file, pathname, description)."""
-            res = None
-            for sub_mod in module_name.split('.'):
-                try:
-                    res = file, path, _ = imp.find_module(sub_mod, path)
-                    path = [path]
-                    if file is not None:
-                        file.close()
-                except ImportError:
-                    # assume namespace package
-                    path = list(sys.modules[sub_mod].__path__)
-                    res = None, path, None
-            return res
-
-        mod_file = find_dotted_module(func.__module__)[1]
-        basedir = os.path.dirname(mod_file)
+    baseline_dir = module_path.parent / 'baseline_images' / subdir
+    result_dir = Path().resolve() / 'result_images' / subdir
+    result_dir.mkdir(parents=True, exist_ok=True)
 
-    baseline_dir = os.path.join(basedir, 'baseline_images', subdir)
-    result_dir = os.path.abspath(os.path.join('result_images', subdir))
-    Path(result_dir).mkdir(parents=True, exist_ok=True)
-
-    return baseline_dir, result_dir
+    return str(baseline_dir), str(result_dir)
 
 
 def switch_backend(backend):
-    # Local import to avoid a hard nose dependency and only incur the
-    # import time overhead at actual test-time.
+
     def switch_backend_decorator(func):
+
         @functools.wraps(func)
         def backend_switcher(*args, **kwargs):
             try:
                 prev_backend = mpl.get_backend()
                 matplotlib.testing.setup()
                 plt.switch_backend(backend)
-                result = func(*args, **kwargs)
+                return func(*args, **kwargs)
             finally:
                 plt.switch_backend(prev_backend)
-            return result
 
-        return _copy_metadata(func, backend_switcher)
+        return backend_switcher
+
     return switch_backend_decorator
 
 
