feat: pass along write_artifacts to loaders

packages/pytest-taskgraph/src/pytest_taskgraph/fixtures/gen.py

@@ -17,7 +17,7 @@
 here = Path(__file__).parent
 
 
-def fake_loader(kind, path, config, parameters, loaded_tasks):
+def fake_loader(kind, path, config, parameters, loaded_tasks, write_artifacts):
     for i in range(3):
         dependencies = {}
         if i >= 1:

src/taskgraph/generator.py

@@ -3,6 +3,7 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 import copy
+import inspect
 import logging
 import multiprocessing
 import os
@@ -60,12 +61,17 @@ def load_tasks(self, parameters, kind_dependencies_tasks, write_artifacts):
         loader = self._get_loader()
         config = copy.deepcopy(self.config)
 
+        if "write_artifacts" in inspect.signature(loader).parameters:
+            extra_args = (write_artifacts,)
+        else:
+            extra_args = ()
         inputs = loader(
             self.name,
             self.path,
             config,
             parameters,
             list(kind_dependencies_tasks.values()),
+            *extra_args,
         )
 
         transforms = TransformSequence()

src/taskgraph/loader/default.py

@@ -16,7 +16,7 @@
 ]
 
 
-def loader(kind, path, config, params, loaded_tasks):
+def loader(kind, path, config, params, loaded_tasks, write_artifacts):
     """
     This default loader builds on the `transform` loader by providing sensible
     default transforms that the majority of simple tasks will need.
@@ -30,4 +30,4 @@ def loader(kind, path, config, params, loaded_tasks):
                 f"Transform {t} is already present in the loader's default transforms; it must not be defined in the kind"
             )
     transform_refs.extend(DEFAULT_TRANSFORMS)
-    return transform_loader(kind, path, config, params, loaded_tasks)
+    return transform_loader(kind, path, config, params, loaded_tasks, write_artifacts)

src/taskgraph/loader/transform.py

@@ -11,7 +11,7 @@
 logger = logging.getLogger(__name__)
 
 
-def loader(kind, path, config, params, loaded_tasks):
+def loader(kind, path, config, params, loaded_tasks, write_artifacts):
     """
     Get the input elements that will be transformed into tasks in a generic
     way.  The elements themselves are free-form, and become the input to the

test/test_generator.py

@@ -216,6 +216,18 @@ def test_load_tasks_for_kind(monkeypatch):
     )
 
 
+def test_loader_backwards_compat_interface(graph_config):
+    """Ensure loaders can be called even if they don't support a
+    `write_artifacts` argument."""
+
+    class OldLoaderKind(Kind):
+        def _get_loader(self):
+            return lambda kind, path, config, params, tasks: []
+
+    kind = OldLoaderKind("", "", {"transforms": []}, graph_config)
+    kind.load_tasks({}, {}, False)
+
+
 @pytest.mark.parametrize(
     "config,expected_transforms",
     (
@@ -243,7 +255,7 @@ def test_default_loader(config, expected_transforms):
     assert loader is default_loader, (
         "Default Kind loader should be taskgraph.loader.default.loader"
     )
-    loader("", "", config, {}, [])
+    loader("", "", config, {}, [], False)
 
     assert config["transforms"] == expected_transforms
 
@@ -273,7 +285,7 @@ def test_default_loader(config, expected_transforms):
 def test_default_loader_errors(config):
     loader = Kind("", "", config, {})._get_loader()
     try:
-        loader("", "", config, {}, [])
+        loader("", "", config, {}, [], False)
     except KeyError:
         return