Unify (parametrize) test_composite across backends.

anntzer · anntzer · commit 98dfc0d3d5d2 · 2017-12-03T01:20:06.000-08:00
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
@@ -81,30 +81,6 @@ def test_savefig_to_stringio(format, use_log, rcParams):
         buffer.close()
 
 
-def test_composite_image():
-    # Test that figures can be saved with and without combining multiple images
-    # (on a single set of axes) into a single composite image.
-    X, Y = np.meshgrid(np.arange(-5, 5, 1), np.arange(-5, 5, 1))
-    Z = np.sin(Y ** 2)
-    fig = plt.figure()
-    ax = fig.add_subplot(1, 1, 1)
-    ax.set_xlim(0, 3)
-    ax.imshow(Z, extent=[0, 1, 0, 1])
-    ax.imshow(Z[::-1], extent=[2, 3, 0, 1])
-    plt.rcParams['image.composite_image'] = True
-    with io.BytesIO() as ps:
-        fig.savefig(ps, format="ps")
-        ps.seek(0)
-        buff = ps.read()
-        assert buff.count(six.b(' colorimage')) == 1
-    plt.rcParams['image.composite_image'] = False
-    with io.BytesIO() as ps:
-        fig.savefig(ps, format="ps")
-        ps.seek(0)
-        buff = ps.read()
-        assert buff.count(six.b(' colorimage')) == 2
-
-
 def test_patheffects():
     with matplotlib.rc_context():
         matplotlib.rcParams['path.effects'] = [
diff --git a/lib/matplotlib/tests/test_backend_svg.py b/lib/matplotlib/tests/test_backend_svg.py
@@ -63,30 +63,6 @@ def test_noscale():
     ax.imshow(Z, cmap='gray', interpolation='none')
 
 
-def test_composite_images():
-    #Test that figures can be saved with and without combining multiple images
-    #(on a single set of axes) into a single composite image.
-    X, Y = np.meshgrid(np.arange(-5, 5, 1), np.arange(-5, 5, 1))
-    Z = np.sin(Y ** 2)
-    fig = plt.figure()
-    ax = fig.add_subplot(1, 1, 1)
-    ax.set_xlim(0, 3)
-    ax.imshow(Z, extent=[0, 1, 0, 1])
-    ax.imshow(Z[::-1], extent=[2, 3, 0, 1])
-    plt.rcParams['image.composite_image'] = True
-    with BytesIO() as svg:
-        fig.savefig(svg, format="svg")
-        svg.seek(0)
-        buff = svg.read()
-        assert buff.count(six.b('<image ')) == 1
-    plt.rcParams['image.composite_image'] = False
-    with BytesIO() as svg:
-        fig.savefig(svg, format="svg")
-        svg.seek(0)
-        buff = svg.read()
-        assert buff.count(six.b('<image ')) == 2
-
-
 def test_text_urls():
     fig = plt.figure()
 
diff --git a/lib/matplotlib/tests/test_image.py b/lib/matplotlib/tests/test_image.py
@@ -86,6 +86,7 @@ def do_figimage(suppressComposite):
     fig.figimage(img[:,::-1], xo=100, yo=0, origin='lower')
     fig.figimage(img[::-1,::-1], xo=100, yo=100, origin='lower')
 
+
 @image_comparison(baseline_images=['figimage-0'],
                   extensions=['png','pdf'])
 def test_figimage0():
@@ -849,3 +850,22 @@ def test_full_invalid():
     ax.imshow(x)
 
     f.canvas.draw()
+
+
+@pytest.mark.parametrize("fmt,counted",
+                         [("ps", b" colorimage"), ("svg", b"<image")])
+@pytest.mark.parametrize("composite_image,count", [(True, 1), (False, 2)])
+def test_composite(fmt, counted, composite_image, count):
+    # Test that figures can be saved with and without combining multiple images
+    # (on a single set of axes) into a single composite image.
+    X, Y = np.meshgrid(np.arange(-5, 5, 1), np.arange(-5, 5, 1))
+    Z = np.sin(Y ** 2)
+    fig = plt.figure()
+    ax = fig.add_subplot(1, 1, 1)
+    ax.set_xlim(0, 3)
+    ax.imshow(Z, extent=[0, 1, 0, 1])
+    ax.imshow(Z[::-1], extent=[2, 3, 0, 1])
+    plt.rcParams['image.composite_image'] = composite_image
+    buf = io.BytesIO()
+    fig.savefig(buf, format=fmt)
+    assert buf.getvalue().count(counted) == count
