Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/matplotlib/tests/test_determinism.py

@@ -0,0 +1,143 @@
+"""
+Test output reproducibility.
+"""
+
+import os
+import subprocess
+import sys
+
+import pytest
+
+import matplotlib as mpl
+import matplotlib.testing.compare
+from matplotlib import pyplot as plt
+
+
+needs_ghostscript = pytest.mark.skipif(
+    "eps" not in mpl.testing.compare.converter,
+    reason="This test needs a ghostscript installation")
+needs_usetex = pytest.mark.skipif(
+    not mpl.checkdep_usetex(True),
+    reason="This test needs a TeX installation")
+
+
+def _save_figure(objects='mhi', fmt="pdf", usetex=False):
+    mpl.use(fmt)
+    mpl.rcParams.update({'svg.hashsalt': 'asdf', 'text.usetex': usetex})
+
+    fig = plt.figure()
+
+    if 'm' in objects:
+        # use different markers...
+        ax1 = fig.add_subplot(1, 6, 1)
+        x = range(10)
+        ax1.plot(x, [1] * 10, marker='D')
+        ax1.plot(x, [2] * 10, marker='x')
+        ax1.plot(x, [3] * 10, marker='^')
+        ax1.plot(x, [4] * 10, marker='H')
+        ax1.plot(x, [5] * 10, marker='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)
+    ax = fig.add_subplot(1, 6, 6)
+    ax.plot(x, x)
+    ax.set_title('A string $1+2+\\sigma$')
+    ax.set_xlabel('A string $1+2+\\sigma$')
+    ax.set_ylabel('A string $1+2+\\sigma$')
+
+    stdout = getattr(sys.stdout, 'buffer', sys.stdout)
+    fig.savefig(stdout, format=fmt)
+
+
+@pytest.mark.parametrize(
+    "objects, fmt, usetex", [
+        ("", "pdf", False),
+        ("m", "pdf", False),
+        ("h", "pdf", False),
+        ("i", "pdf", False),
+        ("mhi", "pdf", False),
+        ("mhi", "ps", False),
+        pytest.param(
+            "mhi", "ps", True, marks=[needs_usetex, needs_ghostscript]),
+        ("mhi", "svg", False),
+        pytest.param("mhi", "svg", True, marks=needs_usetex),
+    ]
+)
+def test_determinism_check(objects, fmt, usetex):
+    """
+    Output three times the same graphs and checks that the outputs are exactly
+    the same.
+
+    Parameters
+    ----------
+    objects : str
+        Objects to be included in the test document: 'm' for markers, 'h' for
+        hatch patterns, 'i' for images.
+    fmt : {"pdf", "ps", "svg"}
+        Output format.
+    """
+    plots = [
+        subprocess.check_output(
+            [sys.executable, "-R", "-c",
+             f"from matplotlib.tests.test_determinism import _save_figure;"
+             f"_save_figure({objects!r}, {fmt!r}, {usetex})"],
+            env={**os.environ, "SOURCE_DATE_EPOCH": "946684800"})
+        for _ in range(3)
+    ]
+    for p in plots[1:]:
+        if fmt == "ps" and usetex:
+            if p != plots[0]:
+                pytest.skip("failed, maybe due to ghostscript timestamps")
+        else:
+            assert p == plots[0]
+
+
+@pytest.mark.parametrize(
+    "fmt, string", [
+        ("pdf", b"/CreationDate (D:20000101000000Z)"),
+        # SOURCE_DATE_EPOCH support is not tested with text.usetex,
+        # because the produced timestamp comes from ghostscript:
+        # %%CreationDate: D:20000101000000Z00\'00\', and this could change
+        # with another ghostscript version.
+        ("ps", b"%%CreationDate: Sat Jan 01 00:00:00 2000"),
+    ]
+)
+def test_determinism_source_date_epoch(fmt, string):
+    """
+    Test SOURCE_DATE_EPOCH support. Output a document with the environment
+    variable SOURCE_DATE_EPOCH set to 2000-01-01 00:00 UTC and check that the
+    document contains the timestamp that corresponds to this date (given as an
+    argument).
+
+    Parameters
+    ----------
+    fmt : {"pdf", "ps", "svg"}
+        Output format.
+    string : bytes
+        Timestamp string for 2000-01-01 00:00 UTC.
+    """
+    buf = subprocess.check_output(
+        [sys.executable, "-R", "-c",
+         f"from matplotlib.tests.test_determinism import _save_figure; "
+         f"_save_figure('', {fmt!r})"],
+        env={**os.environ, "SOURCE_DATE_EPOCH": "946684800"})
+    assert string in buf