Enable branch code coverage

tests/test_pytest_mypy.py

@@ -6,6 +6,8 @@
 import pexpect
 import pytest
 
+import pytest_mypy
+
 
 MYPY_VERSION = Version(mypy.version.__version__)
 PYTEST_VERSION = Version(pytest.__version__)
@@ -554,3 +556,47 @@ def test_mypy_item_collect(request):
     mypy_status_check = 1
     result.assert_outcomes(passed=test_count + mypy_file_checks + mypy_status_check)
     assert result.ret == 0
+
+
+def test_mypy_results_from_mypy_with_opts():
+    """MypyResults.from_mypy respects passed options."""
+    mypy_results = pytest_mypy.MypyResults.from_mypy([], opts=["--version"])
+    assert mypy_results.status == 0
+    assert mypy_results.abspath_errors == {}
+    assert str(MYPY_VERSION) in mypy_results.stdout
+
+
+def test_mypy_no_output(testdir, xdist_args):
+    """No terminal summary is shown if there is no output from mypy."""
+    # Pytest didn't add type annotations until 6.0.
+    type_ignore = "# type: ignore" if PYTEST_VERSION < Version("6.0") else ""
+    testdir.makepyfile(
+        conftest=f"""
+            import tempfile
+
+            import pytest  {type_ignore}
+
+            @pytest.hookimpl(hookwrapper=True)
+            def pytest_terminal_summary(config):
+                pytest_mypy = config.pluginmanager.getplugin("mypy")
+                with open(config._mypy_results_path, mode="r") as results_f:
+                    results = pytest_mypy.MypyResults.load(results_f)
+                with open(config._mypy_results_path, mode="w") as results_f:
+                    pytest_mypy.MypyResults(
+                        opts=results.opts,
+                        stdout=results.stdout,
+                        stderr="",
+                        status=results.status,
+                        abspath_errors=results.abspath_errors,
+                        unmatched_stdout="",
+                    ).dump(results_f)
+                yield
+        """,
+    )
+    result = testdir.runpytest_subprocess("--mypy", *xdist_args)
+    mypy_file_checks = 1
+    mypy_status_check = 1
+    mypy_checks = mypy_file_checks + mypy_status_check
+    result.assert_outcomes(passed=mypy_checks)
+    assert result.ret == 0
+    assert "= mypy =" not in str(result.stdout)

tox.ini

@@ -42,7 +42,7 @@ deps =
     pytest-randomly ~= 3.4
     pytest-xdist ~= 1.34
 
-commands = pytest -p no:mypy {posargs:--cov pytest_mypy --cov-fail-under 100 --cov-report term-missing -n auto}
+commands = pytest -p no:mypy {posargs:--cov pytest_mypy --cov-branch --cov-fail-under 100 --cov-report term-missing -n auto}
 
 [pytest]
 testpaths = tests