feat: add support for returning values (#12)

* Add support for returning values

* Add test file

* Better test

* Black

src/pytest_codspeed/plugin.py

@@ -166,8 +166,11 @@ def _run_with_instrumentation(
         gc.collect()
         gc.disable()
 
+    result = None
+
     def __codspeed_root_frame__():
-        fn(*args, **kwargs)
+        nonlocal result
+        result = fn(*args, **kwargs)
 
     if SUPPORTS_PERF_TRAMPOLINE:
         # Warmup CPython performance map cache
@@ -181,6 +184,8 @@ def __codspeed_root_frame__():
     if is_gc_enabled:
         gc.enable()
 
+    return result
+
 
 @pytest.hookimpl(tryfirst=True)
 def pytest_runtest_protocol(item: "pytest.Item", nextitem: Union["pytest.Item", None]):
@@ -241,11 +246,11 @@ def __call__(self, func: Callable[..., Any], *args: Any, **kwargs: Any) -> Any:
         plugin.benchmark_count += 1
         if plugin.is_codspeed_enabled and plugin.should_measure:
             assert plugin.lib is not None
-            _run_with_instrumentation(
+            return _run_with_instrumentation(
                 plugin.lib, self._request.node.nodeid, func, *args, **kwargs
             )
         else:
-            func(*args, **kwargs)
+            return func(*args, **kwargs)
 
 
 @pytest.fixture(scope="function")

tests/test_pytest_plugin.py

@@ -264,6 +264,21 @@ def test_my_stuff(benchmark):
     assert result.ret == 0, "the run should have succeeded"
 
 
+def test_pytest_benchmark_return_value(pytester: pytest.Pytester) -> None:
+    pytester.makepyfile(
+        """
+        def calculate_something():
+            return 1 + 1
+
+        def test_my_stuff(benchmark):
+            value = benchmark(calculate_something)
+            assert value == 2
+        """
+    )
+    result = pytester.runpytest("--codspeed")
+    assert result.ret == 0, "the run should have succeeded"
+
+
 @skip_without_valgrind
 @skip_without_perf_trampoline
 def test_perf_maps_generation(pytester: pytest.Pytester, codspeed_env) -> None: