Merge pull request #5755 from blueyed/fix-assert-location-with-coverage

Fix wrong location of assertion error with Coverage.py .

Reverts using-constant part from 39ba996.

Fixes https://github.com/pytest-dev/pytest/issues/5754.

src/_pytest/assertion/rewrite.py

@@ -33,9 +33,6 @@ PYTEST_TAG = "{}-pytest-{}".format(sys.implementation.cache_tag, version)
 PYC_EXT = ".py" + (__debug__ and "c" or "o")
 PYC_TAIL = "." + PYTEST_TAG + PYC_EXT
 
-AST_IS = ast.Is()
-AST_NONE = ast.NameConstant(None)
-
 
 class AssertionRewritingHook:
     """PEP302/PEP451 import hook which rewrites asserts."""
@@ -857,7 +854,7 @@ class AssertionRewriter(ast.NodeVisitor):
         internally already.
         See issue #3191 for more details.
         """
-        val_is_none = ast.Compare(node, [AST_IS], [AST_NONE])
+        val_is_none = ast.Compare(node, [ast.Is()], [ast.NameConstant(None)])
         send_warning = ast.parse(
             """\
 from _pytest.warning_types import PytestAssertRewriteWarning

testing/test_assertion.py

@@ -490,7 +490,6 @@ class TestAssert_reprcompare:
         assert len(expl) > 1
 
     def test_Sequence(self):
-
         if not hasattr(collections_abc, "MutableSequence"):
             pytest.skip("cannot import MutableSequence")
         MutableSequence = collections_abc.MutableSequence
@@ -806,9 +805,6 @@ class TestFormatExplanation:
 
 
 class TestTruncateExplanation:
-
-    """ Confirm assertion output is truncated as expected """
-
     # The number of lines in the truncation explanation message. Used
     # to calculate that results have the expected length.
     LINES_IN_TRUNCATION_MSG = 2
@@ -969,7 +965,13 @@ def test_pytest_assertrepr_compare_integration(testdir):
     )
     result = testdir.runpytest()
     result.stdout.fnmatch_lines(
-        ["*def test_hello():*", "*assert x == y*", "*E*Extra items*left*", "*E*50*"]
+        [
+            "*def test_hello():*",
+            "*assert x == y*",
+            "*E*Extra items*left*",
+            "*E*50*",
+            "*= 1 failed in*",
+        ]
     )
 
 
@@ -1302,3 +1304,23 @@ def test_exit_from_assertrepr_compare(monkeypatch):
 
     with pytest.raises(outcomes.Exit, match="Quitting debugger"):
         callequal(1, 1)
+
+
+def test_assertion_location_with_coverage(testdir):
+    """This used to report the wrong location when run with coverage (#5754)."""
+    p = testdir.makepyfile(
+        """
+        def test():
+            assert False, 1
+            assert False, 2
+        """
+    )
+    result = testdir.runpytest(str(p))
+    result.stdout.fnmatch_lines(
+        [
+            ">       assert False, 1",
+            "E       AssertionError: 1",
+            "E       assert False",
+            "*= 1 failed in*",
+        ]
+    )