Add tryserver test_api method

Updates the tryserver recipe module's test_api to support overriding
get_footers data.

Bug: angleproject:7985
Change-Id: Ie571bc8d1c77cbb1cd4f18955b50d56e377ca903
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4278466
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Auto-Submit: Brian Sheedy <bsheedy@chromium.org>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>

recipes/README.recipes.md

@@ -43,6 +43,7 @@
   * [tryserver:tests/gerrit_change_owner](#recipes-tryserver_tests_gerrit_change_owner) (Python3 ✅)
   * [tryserver:tests/gerrit_change_target_ref](#recipes-tryserver_tests_gerrit_change_target_ref) (Python3 ✅)
   * [tryserver:tests/get_files_affected_by_patch](#recipes-tryserver_tests_get_files_affected_by_patch) (Python3 ✅)
+  * [tryserver:tests/get_footers](#recipes-tryserver_tests_get_footers) (Python3 ✅)
   * [tryserver:tests/require_is_tryserver](#recipes-tryserver_tests_require_is_tryserver) (Python3 ✅)
   * [windows_sdk:examples/full](#recipes-windows_sdk_examples_full) (Python3 ✅)
 ## Recipe Modules
@@ -1182,6 +1183,13 @@ PYTHON_VERSION_COMPATIBILITY: PY3
 PYTHON_VERSION_COMPATIBILITY: PY3
 
 — **def [RunSteps](/recipes/recipe_modules/tryserver/tests/get_files_affected_by_patch.py#18)(api):**
+### *recipes* / [tryserver:tests/get\_footers](/recipes/recipe_modules/tryserver/tests/get_footers.py)
+
+[DEPS](/recipes/recipe_modules/tryserver/tests/get_footers.py#9): [tryserver](#recipe_modules-tryserver), [recipe\_engine/assertions][recipe_engine/recipe_modules/assertions], [recipe\_engine/buildbucket][recipe_engine/recipe_modules/buildbucket], [recipe\_engine/path][recipe_engine/recipe_modules/path], [recipe\_engine/platform][recipe_engine/recipe_modules/platform], [recipe\_engine/properties][recipe_engine/recipe_modules/properties]
+
+PYTHON_VERSION_COMPATIBILITY: PY3
+
+— **def [RunSteps](/recipes/recipe_modules/tryserver/tests/get_footers.py#19)(api):**
 ### *recipes* / [tryserver:tests/require\_is\_tryserver](/recipes/recipe_modules/tryserver/tests/require_is_tryserver.py)
 
 [DEPS](/recipes/recipe_modules/tryserver/tests/require_is_tryserver.py#12): [tryserver](#recipe_modules-tryserver), [recipe\_engine/buildbucket][recipe_engine/recipe_modules/buildbucket], [recipe\_engine/properties][recipe_engine/recipe_modules/properties]

recipes/recipe_modules/tryserver/test_api.py

@@ -31,3 +31,18 @@ class TryserverTestApi(recipe_test_api.RecipeTestApi):
     """
     output = self.m.raw_io.stream_output('\n'.join(files))
     return self.override_step_data(step_name, output)
+
+  def get_footers(self, footers, step_name='parse description'):
+    """Override test data for the `get_footers` method.
+
+    Args:
+      footers: A dict containing key/value pairs for footers to return. To be
+          accurate to git_footers.py's actual behavior, values should be lists.
+
+    Example:
+      yield api.test(
+          'my_test',
+          api.tryserver.get_footers({'Footer-Key': ['footer_value']}))
+    """
+    output = self.m.json.output(footers)
+    return self.override_step_data(step_name, output)

recipes/recipe_modules/tryserver/tests/get_footers.py

@@ -0,0 +1,65 @@
+# Copyright 2023 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+from recipe_engine import post_process
+
+PYTHON_VERSION_COMPATIBILITY = 'PY2+3'
+
+DEPS = [
+    'tryserver',
+    'recipe_engine/assertions',
+    'recipe_engine/buildbucket',
+    'recipe_engine/path',
+    'recipe_engine/platform',
+    'recipe_engine/properties',
+]
+
+
+def RunSteps(api):
+  footers = api.tryserver.get_footers()
+  api.assertions.assertCountEqual(footers, api.properties['expected_footers'])
+
+
+def GenTests(api):
+  yield api.test(
+      'no-footers',
+      api.buildbucket.try_build(
+          'chromium',
+          'linux',
+      ),
+      api.properties(expected_footers={}),
+      api.tryserver.get_footers({}),
+      api.post_check(post_process.StatusSuccess),
+      api.post_process(post_process.DropExpectation),
+  )
+
+  yield api.test(
+      'single-footer',
+      api.buildbucket.try_build(
+          'chromium',
+          'linux',
+      ),
+      api.properties(expected_footers={'Some-Footer': ['True']}),
+      api.tryserver.get_footers({'Some-Footer': ['True']}),
+      api.post_check(post_process.StatusSuccess),
+      api.post_process(post_process.DropExpectation),
+  )
+
+  yield api.test(
+      'multiple-footers',
+      api.buildbucket.try_build(
+          'chromium',
+          'linux',
+      ),
+      api.properties(expected_footers={
+          'Some-Footer': ['True'],
+          'Another-Footer': ['Foo', 'Bar']
+      }),
+      api.tryserver.get_footers({
+          'Some-Footer': ['True'],
+          'Another-Footer': ['Foo', 'Bar']
+      }),
+      api.post_check(post_process.StatusSuccess),
+      api.post_process(post_process.DropExpectation),
+  )