Test simplifications.

anntzer · anntzer · commit af4bddd12157 · 2017-10-23T15:14:58.000-07:00
- `assert_produces_warning` is now unused and has been replaced in the
  test suite by `pytest.warns`.

- Replace `assert x, y` by `assert x` when the information in `y` is
  clearly redundant with what pytest's assert rewrite would produce.
  (There are a few cases where the message actually provides more
  information, these are left as is.)
diff --git a/lib/matplotlib/testing/__init__.py b/lib/matplotlib/testing/__init__.py
@@ -51,63 +51,6 @@ def _copy_metadata(src_func, tgt_func):
     return tgt_func
 
 
-# stolen from pandas
-@contextmanager
-def assert_produces_warning(expected_warning=Warning, filter_level="always",
-                            clear=None):
-    """
-    Context manager for running code that expects to raise (or not raise)
-    warnings.  Checks that code raises the expected warning and only the
-    expected warning. Pass ``False`` or ``None`` to check that it does *not*
-    raise a warning. Defaults to ``exception.Warning``, baseclass of all
-    Warnings. (basically a wrapper around ``warnings.catch_warnings``).
-
-    >>> import warnings
-    >>> with assert_produces_warning():
-    ...     warnings.warn(UserWarning())
-    ...
-    >>> with assert_produces_warning(False):
-    ...     warnings.warn(RuntimeWarning())
-    ...
-    Traceback (most recent call last):
-        ...
-    AssertionError: Caused unexpected warning(s): ['RuntimeWarning'].
-    >>> with assert_produces_warning(UserWarning):
-    ...     warnings.warn(RuntimeWarning())
-    Traceback (most recent call last):
-        ...
-    AssertionError: Did not see expected warning of class 'UserWarning'.
-
-    ..warn:: This is *not* thread-safe.
-    """
-    with warnings.catch_warnings(record=True) as w:
-
-        if clear is not None:
-            # make sure that we are clearning these warnings
-            # if they have happened before
-            # to guarantee that we will catch them
-            if not _is_list_like(clear):
-                clear = [clear]
-            for m in clear:
-                getattr(m, "__warningregistry__", {}).clear()
-
-        saw_warning = False
-        warnings.simplefilter(filter_level)
-        yield w
-        extra_warnings = []
-        for actual_warning in w:
-            if (expected_warning and issubclass(actual_warning.category,
-                                                expected_warning)):
-                saw_warning = True
-            else:
-                extra_warnings.append(actual_warning.category.__name__)
-        if expected_warning:
-            assert saw_warning, ("Did not see expected warning of class %r."
-                                 % expected_warning.__name__)
-        assert not extra_warnings, ("Caused unexpected warning(s): %r."
-                                    % extra_warnings)
-
-
 def set_font_settings_for_testing():
     rcParams['font.family'] = 'DejaVu Sans'
     rcParams['text.hinting'] = False
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -1712,33 +1712,29 @@ def _as_mpl_axes(self):
 
     # testing axes creation with plt.axes
     ax = plt.axes([0, 0, 1, 1], projection=prj)
-    assert type(ax) == PolarAxes, \
-        'Expected a PolarAxes, got %s' % type(ax)
+    assert type(ax) == PolarAxes
     ax_via_gca = plt.gca(projection=prj)
     assert ax_via_gca is ax
     plt.close()
 
     # testing axes creation with gca
     ax = plt.gca(projection=prj)
-    assert type(ax) == maxes._subplots._subplot_classes[PolarAxes], \
-        'Expected a PolarAxesSubplot, got %s' % type(ax)
+    assert type(ax) == maxes._subplots._subplot_classes[PolarAxes]
     ax_via_gca = plt.gca(projection=prj)
     assert ax_via_gca is ax
     # try getting the axes given a different polar projection
     ax_via_gca = plt.gca(projection=prj2)
     assert ax_via_gca is not ax
-    assert ax.get_theta_offset() == 0, ax.get_theta_offset()
-    assert ax_via_gca.get_theta_offset() == np.pi, \
-        ax_via_gca.get_theta_offset()
+    assert ax.get_theta_offset() == 0
+    assert ax_via_gca.get_theta_offset() == np.pi
     # try getting the axes given an == (not is) polar projection
     ax_via_gca = plt.gca(projection=prj3)
     assert ax_via_gca is ax
     plt.close()
 
     # testing axes creation with subplot
     ax = plt.subplot(121, projection=prj)
-    assert type(ax) == maxes._subplots._subplot_classes[PolarAxes], \
-        'Expected a PolarAxesSubplot, got %s' % type(ax)
+    assert type(ax) == maxes._subplots._subplot_classes[PolarAxes]
     plt.close()
 
 
@@ -4956,12 +4952,7 @@ def _helper_y(ax):
         r = ax.yaxis.get_major_locator()()
         assert r[-1] > 14
 
-    if request.param == 'x':
-        return _helper_x
-    elif request.param == 'y':
-        return _helper_y
-    else:
-        assert False, 'Request param %s is invalid.' % (request.param, )
+    return {"x": _helper_x, "y": _helper_y}[request.param]
 
 
 @pytest.fixture(params=['gca', 'subplots', 'subplots_shared', 'add_axes'])
@@ -4978,9 +4969,6 @@ def shared_axes_generator(request):
     elif request.param == 'add_axes':
         fig = plt.figure()
         ax = fig.add_axes([.1, .1, .8, .8])
-    else:
-        assert False, 'Request param %s is invalid.' % (request.param, )
-
     return fig, ax
 
 
diff --git a/lib/matplotlib/tests/test_cycles.py b/lib/matplotlib/tests/test_cycles.py
@@ -179,7 +179,7 @@ def test_cycle_reset():
     assert prop != next(ax._get_lines.prop_cycler)
     ax.set_prop_cycle(None)
     got = next(ax._get_lines.prop_cycler)
-    assert prop == got, "expected %s, got %s" % (prop, got)
+    assert prop == got
 
     fig, ax = plt.subplots()
     # Need to double-check the old set/get_color_cycle(), too
@@ -190,7 +190,7 @@ def test_cycle_reset():
         assert prop != next(ax._get_lines.prop_cycler)
         ax.set_color_cycle(None)
         got = next(ax._get_lines.prop_cycler)
-        assert prop == got, "expected %s, got %s" % (prop, got)
+        assert prop == got
 
 
 def test_invalid_input_forms():
diff --git a/lib/matplotlib/tests/test_image.py b/lib/matplotlib/tests/test_image.py
@@ -201,17 +201,15 @@ def test_cursor_data():
     xdisp, ydisp = ax.transData.transform_point([x, y])
 
     event = MouseEvent('motion_notify_event', fig.canvas, xdisp, ydisp)
-    z = im.get_cursor_data(event)
-    assert z == 44, "Did not get 44, got %d" % z
+    assert im.get_cursor_data(event) == 44
 
     # Now try for a point outside the image
     # Tests issue #4957
     x, y = 10.1, 4
     xdisp, ydisp = ax.transData.transform_point([x, y])
 
     event = MouseEvent('motion_notify_event', fig.canvas, xdisp, ydisp)
-    z = im.get_cursor_data(event)
-    assert z is None, "Did not get None, got %d" % z
+    assert im.get_cursor_data(event) is None
 
     # Hmm, something is wrong here... I get 0, not None...
     # But, this works further down in the tests with extents flipped
@@ -229,8 +227,7 @@ def test_cursor_data():
     xdisp, ydisp = ax.transData.transform_point([x, y])
 
     event = MouseEvent('motion_notify_event', fig.canvas, xdisp, ydisp)
-    z = im.get_cursor_data(event)
-    assert z == 44, "Did not get 44, got %d" % z
+    assert im.get_cursor_data(event) == 44
 
     fig, ax = plt.subplots()
     im = ax.imshow(np.arange(100).reshape(10, 10), extent=[0, 0.5, 0, 0.5])
@@ -239,24 +236,21 @@ def test_cursor_data():
     xdisp, ydisp = ax.transData.transform_point([x, y])
 
     event = MouseEvent('motion_notify_event', fig.canvas, xdisp, ydisp)
-    z = im.get_cursor_data(event)
-    assert z == 55, "Did not get 55, got %d" % z
+    assert im.get_cursor_data(event) == 55
 
     # Now try for a point outside the image
     # Tests issue #4957
     x, y = 0.75, 0.25
     xdisp, ydisp = ax.transData.transform_point([x, y])
 
     event = MouseEvent('motion_notify_event', fig.canvas, xdisp, ydisp)
-    z = im.get_cursor_data(event)
-    assert z is None, "Did not get None, got %d" % z
+    assert im.get_cursor_data(event) is None
 
     x, y = 0.01, -0.01
     xdisp, ydisp = ax.transData.transform_point([x, y])
 
     event = MouseEvent('motion_notify_event', fig.canvas, xdisp, ydisp)
-    z = im.get_cursor_data(event)
-    assert z is None, "Did not get None, got %d" % z
+    assert im.get_cursor_data(event) is None
 
 
 @image_comparison(baseline_images=['image_clip'], style='mpl20')
@@ -295,15 +289,19 @@ def test_imshow():
     ax.set_xlim(0,3)
     ax.set_ylim(0,3)
 
-@image_comparison(baseline_images=['no_interpolation_origin'], remove_text=True)
+
+@image_comparison(baseline_images=['no_interpolation_origin'],
+                  remove_text=True)
 def test_no_interpolation_origin():
     fig = plt.figure()
     ax = fig.add_subplot(211)
-    ax.imshow(np.arange(100).reshape((2, 50)), origin="lower", interpolation='none')
+    ax.imshow(np.arange(100).reshape((2, 50)), origin="lower",
+              interpolation='none')
 
     ax = fig.add_subplot(212)
     ax.imshow(np.arange(100).reshape((2, 50)), interpolation='none')
 
+
 @image_comparison(baseline_images=['image_shift'], remove_text=True,
                   extensions=['pdf', 'svg'])
 def test_image_shift():
@@ -319,6 +317,7 @@ def test_image_shift():
               extent=(tMin, tMax, 1, 100))
     ax.set_aspect('auto')
 
+
 def test_image_edges():
     f = plt.figure(figsize=[1, 1])
     ax = f.add_axes([0, 0, 1, 1], frameon=False)
@@ -514,11 +513,10 @@ def test_jpeg_alpha():
     # If this fails, there will be only one color (all black). If this
     # is working, we should have all 256 shades of grey represented.
     num_colors = len(image.getcolors(256))
-    assert 175 <= num_colors <= 185, 'num colors: %d' % (num_colors, )
-    # The fully transparent part should be red, not white or black
-    # or anything else
+    assert 175 <= num_colors <= 185
+    # The fully transparent part should be red.
     corner_pixel = image.getpixel((0, 0))
-    assert corner_pixel == (254, 0, 0), "corner pixel: %r" % (corner_pixel, )
+    assert corner_pixel == (254, 0, 0)
 
 
 def test_nonuniformimage_setdata():
diff --git a/lib/matplotlib/tests/test_patheffects.py b/lib/matplotlib/tests/test_patheffects.py
@@ -111,10 +111,7 @@ def test_PathEffect_points_to_pixels():
     renderer = fig.canvas.get_renderer()
     pe_renderer = path_effects.SimpleLineShadow().get_proxy_renderer(renderer)
 
-    assert isinstance(pe_renderer, path_effects.PathEffectRenderer), (
-                'Expected a PathEffectRendere instance, got '
-                'a {0} instance.'.format(type(pe_renderer)))
-
+    assert isinstance(pe_renderer, path_effects.PathEffectRenderer)
     # Confirm that using a path effects renderer maintains point sizes
     # appropriately. Otherwise rendered font would be the wrong size.
     assert renderer.points_to_pixels(15) == pe_renderer.points_to_pixels(15)
diff --git a/lib/matplotlib/tests/test_widgets.py b/lib/matplotlib/tests/test_widgets.py
@@ -128,7 +128,7 @@ def onselect(epress, erelease):
                     key=' ')
     do_event(tool, 'onmove', xdata=30, ydata=30, button=1)
     do_event(tool, 'release', xdata=30, ydata=30, button=1)
-    assert tool.extents == (120, 170, 120, 170), tool.extents
+    assert tool.extents == (120, 170, 120, 170)
 
     # create from center
     do_event(tool, 'on_key_press', xdata=100, ydata=100, button=1,
@@ -138,7 +138,7 @@ def onselect(epress, erelease):
     do_event(tool, 'release', xdata=125, ydata=125, button=1)
     do_event(tool, 'on_key_release', xdata=100, ydata=100, button=1,
                     key='control')
-    assert tool.extents == (75, 125, 75, 125), tool.extents
+    assert tool.extents == (75, 125, 75, 125)
 
     # create a square
     do_event(tool, 'on_key_press', xdata=10, ydata=10, button=1,
@@ -160,7 +160,7 @@ def onselect(epress, erelease):
     do_event(tool, 'on_key_release', xdata=100, ydata=100, button=1,
                       key='ctrl+shift')
     extents = [int(e) for e in tool.extents]
-    assert extents == [70, 129, 70, 130], extents
+    assert extents == [70, 129, 70, 130]
 
     assert tool.geometry.shape == (2, 73)
     assert_allclose(tool.geometry[:, 0], [70., 100])
