Adjust test expectations for lcov reports generated under PyPy 3.8.

There is a bug somewhere, in which if we collect data in --branch mode under
PyPy 3.8, regions for top-level functions come out of the analysis engine with
empty lines arrays.  The previous commit prevented this from crashing the lcov
reporter; this commit adjusts the tests of the lcov reporter so that we expect
the function records affected by the bug to be missing.

I don’t think it’s worth trying to pin down the cause of the bug, since Python
3.8 is approaching end-of-life for both CPython and PyPy.

Author: zackw

coverage/lcovreport.py

@@ -63,6 +63,11 @@ def lcov_functions(
     # We continue to generate the old format because we don't know what
     # version of the lcov tools will be used to read this report.
 
+    # "and region.lines" below avoids a crash due to a bug in PyPy 3.8
+    # where, for whatever reason, when collecting data in --branch mode,
+    # top-level functions have an empty lines array.  Instead we just don't
+    # emit function records for those.
+
     # suppressions because of https://github.com/pylint-dev/pylint/issues/9923
     functions = [
         (min(region.start, min(region.lines)), #pylint: disable=nested-min-max

tests/test_lcov.py

@@ -11,6 +11,24 @@
 from tests.coveragetest import CoverageTest
 
 import coverage
+from coverage import env
+
+
+def fn_coverage_missing_in_pypy_38(
+    line_records: str,
+    fn_records: str,
+    arc_records: str,
+) -> str:
+    """
+    Helper for tests that trip a bug in PyPy 3.8 that prevent us from
+    generating function coverage records for top-level functions when
+    coverage data was collected in --branch mode.  See lcov_functions
+    in lcovreport.py for more detail.
+    """
+    if env.PYPY and env.PYVERSION[:2] == (3, 8):
+        return line_records + arc_records
+    else:
+        return line_records + fn_records + arc_records
 
 
 class LcovTest(CoverageTest):
@@ -174,24 +192,30 @@ def is_it_x(x):
         pct = cov.lcov_report()
         assert math.isclose(pct, 16.666666666666668)
         self.assert_exists("coverage.lcov")
-        expected_result = textwrap.dedent("""\
-            SF:main_file.py
-            DA:1,1
-            DA:2,0
-            DA:3,0
-            DA:5,0
-            LF:4
-            LH:1
-            FN:1,5,is_it_x
-            FNDA:0,is_it_x
-            FNF:1
-            FNH:0
-            BRDA:2,0,to line 3,-
-            BRDA:2,0,to line 5,-
-            BRF:2
-            BRH:0
-            end_of_record
-            """)
+        expected_result = fn_coverage_missing_in_pypy_38(
+            textwrap.dedent("""\
+                SF:main_file.py
+                DA:1,1
+                DA:2,0
+                DA:3,0
+                DA:5,0
+                LF:4
+                LH:1
+                """),
+            textwrap.dedent("""\
+                FN:1,5,is_it_x
+                FNDA:0,is_it_x
+                FNF:1
+                FNH:0
+                """),
+            textwrap.dedent("""\
+                BRDA:2,0,to line 3,-
+                BRDA:2,0,to line 5,-
+                BRF:2
+                BRH:0
+                end_of_record
+                """)
+            )
         actual_result = self.get_lcov_report_content()
         assert expected_result == actual_result
 
@@ -221,23 +245,33 @@ def test_is_it_x(self):
         pct = cov.lcov_report()
         assert math.isclose(pct, 41.666666666666664)
         self.assert_exists("coverage.lcov")
-        expected_result = textwrap.dedent("""\
-            SF:main_file.py
-            DA:1,1
-            DA:2,0
-            DA:3,0
-            DA:5,0
-            LF:4
-            LH:1
-            FN:1,5,is_it_x
-            FNDA:0,is_it_x
-            FNF:1
-            FNH:0
-            BRDA:2,0,to line 3,-
-            BRDA:2,0,to line 5,-
-            BRF:2
-            BRH:0
-            end_of_record
+        # The pypy 3.8 bug that prevents us from generating function coverage
+        # records only applies to top-level functions, not to member functions.
+        expected_result = fn_coverage_missing_in_pypy_38(
+            textwrap.dedent("""\
+                SF:main_file.py
+                DA:1,1
+                DA:2,0
+                DA:3,0
+                DA:5,0
+                LF:4
+                LH:1
+                """),
+            textwrap.dedent("""\
+                FN:1,5,is_it_x
+                FNDA:0,is_it_x
+                FNF:1
+                FNH:0
+                """),
+            textwrap.dedent("""\
+                BRDA:2,0,to line 3,-
+                BRDA:2,0,to line 5,-
+                BRF:2
+                BRH:0
+                end_of_record
+                """)
+            )
+        expected_result += textwrap.dedent("""\
             SF:test_file.py
             DA:1,1
             DA:2,1
@@ -371,27 +405,33 @@ def foo(a):
         cov = coverage.Coverage(source=".", branch=True)
         self.start_import_stop(cov, "runme")
         cov.lcov_report()
-        expected_result = textwrap.dedent("""\
-            SF:runme.py
-            DA:1,1
-            DA:2,1
-            DA:3,1
-            DA:4,1
-            DA:5,1
-            DA:6,1
-            DA:7,1
-            LF:7
-            LH:7
-            FN:1,3,foo
-            FNDA:1,foo
-            FNF:1
-            FNH:1
-            BRDA:2,0,to line 3,1
-            BRDA:2,0,to exit,1
-            BRF:2
-            BRH:2
-            end_of_record
-        """)
+        expected_result = fn_coverage_missing_in_pypy_38(
+            textwrap.dedent("""\
+                SF:runme.py
+                DA:1,1
+                DA:2,1
+                DA:3,1
+                DA:4,1
+                DA:5,1
+                DA:6,1
+                DA:7,1
+                LF:7
+                LH:7
+                """),
+            textwrap.dedent("""\
+                FN:1,3,foo
+                FNDA:1,foo
+                FNF:1
+                FNH:1
+                """),
+            textwrap.dedent("""\
+                BRDA:2,0,to line 3,1
+                BRDA:2,0,to exit,1
+                BRF:2
+                BRH:2
+                end_of_record
+                """),
+        )
         actual_result = self.get_lcov_report_content()
         assert expected_result == actual_result
 
@@ -408,27 +448,33 @@ def foo(a):
         cov = coverage.Coverage(source=".", branch=True)
         self.start_import_stop(cov, "runme")
         cov.lcov_report()
-        expected_result = textwrap.dedent("""\
-            SF:runme.py
-            DA:1,1
-            DA:2,1
-            DA:3,1
-            DA:4,1
-            DA:5,1
-            DA:6,1
-            DA:7,1
-            LF:7
-            LH:7
-            FN:1,3,foo
-            FNDA:1,foo
-            FNF:1
-            FNH:1
-            BRDA:2,0,to line 3,1
-            BRDA:2,0,to exit 1,1
-            BRDA:2,0,to exit 2,1
-            BRF:2
-            BRH:2
-            end_of_record
-        """)
+        expected_result = fn_coverage_missing_in_pypy_38(
+            textwrap.dedent("""\
+                SF:runme.py
+                DA:1,1
+                DA:2,1
+                DA:3,1
+                DA:4,1
+                DA:5,1
+                DA:6,1
+                DA:7,1
+                LF:7
+                LH:7
+                """),
+            textwrap.dedent("""\
+                FN:1,3,foo
+                FNDA:1,foo
+                FNF:1
+                FNH:1
+                """),
+            textwrap.dedent("""\
+                BRDA:2,0,to line 3,1
+                BRDA:2,0,to exit 1,1
+                BRDA:2,0,to exit 2,1
+                BRF:2
+                BRH:2
+                end_of_record
+                """),
+        )
         actual_result = self.get_lcov_report_content()
         assert expected_result == actual_result