Tests for determinist PDF output:

Alexis Bienvenüe · Alexis Bienvenüe · commit 22f71a28271b · 2016-06-18T18:07:21.000+02:00
- SOURCE_DATE_EPOCH support
- reproducible output
diff --git a/lib/matplotlib/tests/test_backend_pdf.py b/lib/matplotlib/tests/test_backend_pdf.py
@@ -109,6 +109,137 @@ def test_composite_image():
         assert len(pdf._file._images.keys()) == 2
 
 
+@cleanup
+def test_source_date_epoch():
+    # Test SOURCE_DATE_EPOCH support
+    try:
+        # save current value of SOURCE_DATE_EPOCH
+        sde = os.environ.pop('SOURCE_DATE_EPOCH',None)
+        fig = plt.figure()
+        ax = fig.add_subplot(1, 1, 1)
+        x = [1, 2, 3, 4, 5]
+        ax.plot(x, x)
+        os.environ['SOURCE_DATE_EPOCH'] = "946684800"
+        with io.BytesIO() as pdf:
+            fig.savefig(pdf, format="pdf")
+            pdf.seek(0)
+            buff = pdf.read()
+            assert b"/CreationDate (D:20000101000000Z)" in buff
+        os.environ.pop('SOURCE_DATE_EPOCH',None)
+        with io.BytesIO() as pdf:
+            fig.savefig(pdf, format="pdf")
+            pdf.seek(0)
+            buff = pdf.read()
+            assert not b"/CreationDate (D:20000101000000Z)" in buff
+    finally:
+        # Restores SOURCE_DATE_EPOCH
+        if sde == None:
+            os.environ.pop('SOURCE_DATE_EPOCH',None)
+        else:
+            os.environ['SOURCE_DATE_EPOCH'] = sde
+
+
+def _test_determinism_save(filename, objects=''):
+    # save current value of SOURCE_DATE_EPOCH and set it
+    # to a constant value, so that time difference is not
+    # taken into account
+    sde = os.environ.pop('SOURCE_DATE_EPOCH',None)
+    os.environ['SOURCE_DATE_EPOCH'] = "946684800"
+
+    fig = plt.figure()
+
+    if 'm' in objects:
+        # use different markers, to be recorded in the PdfFile object
+        ax1 = fig.add_subplot(1, 6, 1)
+        x = range(10)
+        ax1.plot(x, [1] * 10, marker=u'D')
+        ax1.plot(x, [2] * 10, marker=u'x')
+        ax1.plot(x, [3] * 10, marker=u'^')
+        ax1.plot(x, [4] * 10, marker=u'H')
+        ax1.plot(x, [5] * 10, marker=u'v')
+
+    if 'h' in objects:
+        # also use different hatch patterns
+        ax2 = fig.add_subplot(1, 6, 2)
+        bars = ax2.bar(range(1, 5), range(1, 5)) + \
+               ax2.bar(range(1, 5), [6] * 4, bottom=range(1, 5))
+        ax2.set_xticks([1.5, 2.5, 3.5, 4.5])
+
+        patterns = ('-', '+', 'x', '\\', '*', 'o', 'O', '.')
+        for bar, pattern in zip(bars, patterns):
+            bar.set_hatch(pattern)
+
+    if 'i' in objects:
+        # also use different images
+        A = [[1, 2, 3], [2, 3, 1], [3, 1, 2]]
+        fig.add_subplot(1, 6, 3).imshow(A, interpolation='nearest')
+        A = [[1, 3, 2], [1, 2, 3], [3, 1, 2]]
+        fig.add_subplot(1, 6, 4).imshow(A, interpolation='bilinear')
+        A = [[2, 3, 1], [1, 2, 3], [2, 1, 3]]
+        fig.add_subplot(1, 6, 5).imshow(A, interpolation='bicubic')
+
+    x=range(5)
+    fig.add_subplot(1, 6, 6).plot(x,x)
+
+    fig.savefig(filename, format="pdf")
+
+    # Restores SOURCE_DATE_EPOCH
+    if sde == None:
+        os.environ.pop('SOURCE_DATE_EPOCH',None)
+    else:
+        os.environ['SOURCE_DATE_EPOCH'] = sde
+
+
+def _test_determinism(objects=''):
+    import sys
+    from subprocess import check_call
+    from nose.tools import assert_equal
+    filename = 'determinism_O%s.pdf' % objects
+    plots = []
+    for i in range(3):
+        check_call([sys.executable, '-R', '-c',
+                    'import matplotlib; '
+                    'matplotlib.use("pdf"); '
+                    'from matplotlib.tests.test_backend_pdf '
+                    'import _test_determinism_save;'
+                    '_test_determinism_save(%r,%r)' % (filename,objects)])
+        with open(filename, 'rb') as fd:
+            plots.append(fd.read())
+        os.unlink(filename)
+    for p in plots[1:]:
+        assert_equal(p,plots[0])
+
+
+@cleanup
+def test_determinism_plain():
+    """Test for reproducible PDF output: simple figure"""
+    _test_determinism()
+
+
+@cleanup
+def test_determinism_images():
+    """Test for reproducible PDF output: figure with different images"""
+    _test_determinism('i')
+
+
+@cleanup
+def test_determinism_hatches():
+    """Test for reproducible PDF output: figure with different hatches"""
+    _test_determinism('h')
+
+
+@cleanup
+def test_determinism_markers():
+    """Test for reproducible PDF output: figure with different markers"""
+    _test_determinism('m')
+
+
+@cleanup
+def test_determinism_all():
+    """Test for reproducible PDF output"""
+    _test_determinism('mhi')
+
+
 @image_comparison(baseline_images=['hatching_legend'],
                   extensions=['pdf'])
 def test_hatching_legend():
