Test: Verify "cat .readthedocs.yaml" was called (#10495)

Nice to test this behavior somewhere

Author: benjaoming

readthedocs/projects/tests/test_build_tasks.py

@@ -704,6 +704,11 @@ def test_build_commands_executed(
 
         self.mocker.mocks["environment.run"].assert_has_calls(
             [
+                mock.call(
+                    "cat",
+                    "readthedocs.yaml",
+                    cwd="/tmp/readthedocs-tests/git-repository",
+                ),
                 mock.call(
                     "python3.7",
                     "-mvirtualenv",