Test coverage of branching.

Also test coverage of test code.

pylint_silent/__main__.py

@@ -58,5 +58,5 @@ def main() -> int:
     return 1  # pragma: no cover
 
 
-if __name__ == "__main__":
+if __name__ == "__main__":  # pragma: no cover
     sys.exit(main())

tests/test_samples.py

@@ -20,7 +20,7 @@ def run_pylint_silent(*args: str) -> Union[int, str, None]:
             runpy.run_module("pylint_silent", run_name="__main__")
         except SystemExit as ex:
             return ex.code
-        return None
+        raise RuntimeError  # pragma: no cover # pylint_silent alway raises SystemExit
 
 
 # pylint: disable-next=too-few-public-methods,too-many-instance-attributes; silent
@@ -131,6 +131,17 @@ def test_apply(ctx: Context) -> None:
     assert exitcode == 0
 
 
+def test_apply_empty(ctx: Context) -> None:
+    """Test 'pylint-silent apply' with empty file."""
+    pylint_output = ctx.temp_sample_filename + "lint-empty"
+    # Create empty file:
+    with open(pylint_output, "w", encoding="utf-8"):
+        pass
+
+    # Apply pylint-silent changed based on empty file:
+    run_pylint_silent("apply", pylint_output)
+
+
 def test_apply_signature(ctx: Context) -> None:
     """Test 'pylint-silent apply'."""
     # Run pylint on test files.

tox.ini

@@ -51,10 +51,13 @@ deps =
     coverage
 
 commands =
-    coverage run -m --source=pylint_silent pytest tests
+    coverage run -m pytest tests
     coverage html
     coverage report --show-missing --fail-under=100
 
+[coverage:run]
+branch = True
+
 [pycodestyle]
 # Line length of 88 copied from black.
 max-line-length = 88