Move tests to nocover

hypothesis-python/tests/cover/test_scrutineer.py

@@ -19,60 +19,17 @@
 import pytest
 
 from hypothesis.internal.compat import PYPY
-from hypothesis.internal.scrutineer import HAD_TRACE, make_report
+from hypothesis.internal.scrutineer import HAD_TRACE
 
-BUG_MARKER = "# BUG"
-PRELUDE = """
+CODE_SAMPLE = """
 from hypothesis import Phase, given, settings, strategies as st
 
 @settings(phases=tuple(Phase), derandomize=True)
-"""
-
-
-def expected_reports(file_contents, fname):
-    # Takes the source code string with "# BUG" comments, and returns a list of
-    # multi-line report strings which we expect to see in explain-mode output.
-    # The list length is the number of explainable bugs, usually one.
-    explanations = {
-        i: {(fname, i)}
-        for i, line in enumerate(file_contents.splitlines())
-        if line.endswith(BUG_MARKER)
-    }
-    return ["\n".join(r) for k, r in make_report(explanations).items()]
-
-
-TRIVIAL = """
 @given(st.integers())
 def test_reports_branch_in_test(x):
     if x > 10:
         raise AssertionError  # BUG
 """
-MULTIPLE_BUGS = """
-@given(st.integers(), st.integers())
-def test_reports_branch_in_test(x, y):
-    if x > 10:
-        raise (AssertionError if x % 2 else Exception)  # BUG
-"""
-
-
-# We skip tracing for explanations under PyPy, where it has a large performance
-# impact, or if there is already a trace function (e.g. coverage or a debugger)
-@pytest.mark.skipif(PYPY or sys.gettrace(), reason="See comment")
-@pytest.mark.parametrize(
-    "code",
-    [
-        pytest.param(TRIVIAL, id="trivial"),
-        pytest.param(MULTIPLE_BUGS, id="multiple-bugs"),
-    ],
-)
-def test_explanations(code, testdir):
-    code = PRELUDE + code
-    test_file = str(testdir.makepyfile(code))
-    pytest_stdout = str(testdir.runpytest_inprocess(test_file, "--tb=native").stdout)
-    expected = expected_reports(code, fname=test_file)
-    assert len(expected) == code.count(BUG_MARKER)
-    for report in expected:
-        assert report in pytest_stdout
 
 
 @pytest.mark.skipif(PYPY, reason="Tracing is slow under PyPy")
@@ -85,9 +42,7 @@ def test_cannot_explain_message(testdir):
     try:
         if no_tracer:
             sys.settrace(lambda frame, event, arg: None)
-
-        code = PRELUDE + TRIVIAL
-        test_file = testdir.makepyfile(code)
+        test_file = testdir.makepyfile(CODE_SAMPLE)
         testdir.runpytest_inprocess(test_file, "--tb=native").stdout.re_match_lines(
             [r"Explanation:", re.escape(HAD_TRACE)], consecutive=True
         )

hypothesis-python/tests/nocover/test_scrutineer.py

@@ -0,0 +1,72 @@
+# This file is part of Hypothesis, which may be found at
+# https://github.com/HypothesisWorks/hypothesis/
+#
+# Most of this work is copyright (C) 2013-2021 David R. MacIver
+# (david@drmaciver.com), but it contains contributions by others. See
+# CONTRIBUTING.rst for a full list of people who may hold copyright, and
+# consult the git log if you need to determine who owns an individual
+# contribution.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public License,
+# v. 2.0. If a copy of the MPL was not distributed with this file, You can
+# obtain one at https://mozilla.org/MPL/2.0/.
+#
+# END HEADER
+
+import sys
+
+import pytest
+
+from hypothesis.internal.compat import PYPY
+from hypothesis.internal.scrutineer import make_report
+
+# We skip tracing for explanations under PyPy, where it has a large performance
+# impact, or if there is already a trace function (e.g. coverage or a debugger)
+pytestmark = pytest.mark.skipif(PYPY or sys.gettrace(), reason="See comment")
+
+BUG_MARKER = "# BUG"
+PRELUDE = """
+from hypothesis import Phase, given, settings, strategies as st
+
+@settings(phases=tuple(Phase), derandomize=True)
+"""
+TRIVIAL = """
+@given(st.integers())
+def test_reports_branch_in_test(x):
+    if x > 10:
+        raise AssertionError  # BUG
+"""
+MULTIPLE_BUGS = """
+@given(st.integers(), st.integers())
+def test_reports_branch_in_test(x, y):
+    if x > 10:
+        raise (AssertionError if x % 2 else Exception)  # BUG
+"""
+FRAGMENTS = (
+    pytest.param(TRIVIAL, id="trivial"),
+    pytest.param(MULTIPLE_BUGS, id="multiple-bugs"),
+)
+
+
+def get_reports(file_contents, *, testdir):
+    # Takes the source code string with "# BUG" comments, and returns a list of
+    # multi-line report strings which we expect to see in explain-mode output.
+    # The list length is the number of explainable bugs, usually one.
+    test_file = str(testdir.makepyfile(file_contents))
+    pytest_stdout = str(testdir.runpytest_inprocess(test_file, "--tb=native").stdout)
+
+    explanations = {
+        i: {(test_file, i)}
+        for i, line in enumerate(file_contents.splitlines())
+        if line.endswith(BUG_MARKER)
+    }
+    expected = ["\n".join(r) for k, r in make_report(explanations).items()]
+    return pytest_stdout, expected
+
+
+@pytest.mark.parametrize("code", FRAGMENTS)
+def test_explanations(code, testdir):
+    pytest_stdout, expected = get_reports(PRELUDE + code, testdir=testdir)
+    assert len(expected) == code.count(BUG_MARKER)
+    for report in expected:
+        assert report in pytest_stdout