Add support for pytest fixtures from local pytest plugins.

jedi/plugins/pytest.py

@@ -181,6 +181,9 @@ def _iter_pytest_modules(module_context, skip_own_module=False):
             if Path(file_io.path) != module_context.py__file__():
                 try:
                     m = load_module_from_path(module_context.inference_state, file_io)
+                    pytest_plugins_pointer = m.goto("pytest_plugins")
+                    if pytest_plugins_pointer:
+                        yield from _load_pytest_plugins(module_context, pytest_plugins_pointer[0])
                     yield m.as_context()
                 except FileNotFoundError:
                     pass
@@ -196,6 +199,17 @@ def _iter_pytest_modules(module_context, skip_own_module=False):
             yield module_value.as_context()
 
 
+def _load_pytest_plugins(module_context, plugins_pointers):
+    from jedi.inference.value import iterable
+    from parso.python.tree import String
+    for inferred in plugins_pointers.infer():
+        if isinstance(inferred, iterable.SequenceLiteralValue):
+            for value in inferred.get_tree_entries():
+                if isinstance(value, String):
+                    for module_value in module_context.inference_state.import_module(eval(value.value).split(".")):
+                        yield module_value.as_context()
+
+
 class FixtureFilter(ParserTreeFilter):
     def _filter(self, names):
         for name in super()._filter(names):

test/completion/conftest.py

@@ -27,3 +27,9 @@ def capsysbinary(capsysbinary):
     #? ['close']
     capsysbinary.clos
     return capsysbinary
+
+
+# used when fixtures are defined in multiple files
+pytest_plugins = [
+    "completion.fixture_module",
+]

test/completion/fixture_module.py

@@ -0,0 +1,6 @@
+# Exists only for completion/pytest.py
+import pytest
+
+@pytest.fixture
+def my_module_fixture():
+    return 1.0

test/completion/pytest.py

@@ -96,6 +96,9 @@ def test_x(my_con
 #? 18 ['my_conftest_fixture']
 def test_x(my_conftest_fixture):
     return
+#? ['my_module_fixture']
+def test_x(my_modu
+    return
 
 #? []
 def lala(my_con