Merge pull request #4076 from nicoddemus/unittest-param-fixture-msg

Improve error message when TestCase functions use a parametrized fixture

src/_pytest/fixtures.py

@@ -564,7 +564,20 @@ class FixtureRequest(FuncargnamesCompatAttr):
         except (AttributeError, ValueError):
             param = NOTSET
             param_index = 0
-            if fixturedef.params is not None:
+            has_params = fixturedef.params is not None
+            fixtures_not_supported = getattr(funcitem, "nofuncargs", False)
+            if has_params and fixtures_not_supported:
+                msg = (
+                    "{name} does not support fixtures, maybe unittest.TestCase subclass?\n"
+                    "Node id: {nodeid}\n"
+                    "Function type: {typename}"
+                ).format(
+                    name=funcitem.name,
+                    nodeid=funcitem.nodeid,
+                    typename=type(funcitem).__name__,
+                )
+                fail(msg)
+            if has_params:
                 frame = inspect.stack()[3]
                 frameinfo = inspect.getframeinfo(frame[0])
                 source_path = frameinfo.filename
@@ -573,9 +586,11 @@ class FixtureRequest(FuncargnamesCompatAttr):
                 if source_path.relto(funcitem.config.rootdir):
                     source_path = source_path.relto(funcitem.config.rootdir)
                 msg = (
-                    "The requested fixture has no parameter defined for the "
-                    "current test.\n\nRequested fixture '{}' defined in:\n{}"
+                    "The requested fixture has no parameter defined for test:\n"
+                    "    {}\n\n"
+                    "Requested fixture '{}' defined in:\n{}"
                     "\n\nRequested here:\n{}:{}".format(
+                        funcitem.nodeid,
                         fixturedef.argname,
                         getlocation(fixturedef.func, funcitem.config.rootdir),
                         source_path,