Publish our type annotationschandan/publish-types

As defined by PEP 561 (https://www.python.org/dev/peps/pep-0561), add a
`py.typed` file to the BuildStream package. This allows any downstream
packages (currently plugins, maybe other use cases in future) to run
type checkers against BuildStream as well.

Although we don't have type hints for the private API surface,
downstream packages should only be using public API anyway, so they
should mostly be fine.

2 files changed, 8 insertions, 1 deletions

diff --git a/setup.py b/setup.py
index c300d33e9..930c9de40 100755
--- a/setup.py
+++ b/setup.py
@@ -347,7 +347,14 @@ setup(
     package_dir={"": "src"},
     packages=find_packages(where="src", exclude=("tests", "tests.*")),
     package_data={
-        "buildstream": ["plugins/*/*.py", "plugins/*/*.yaml", "data/*.yaml", "data/*.sh.in", *list_testing_datafiles()]
+        "buildstream": [
+            "py.typed",
+            "plugins/*/*.py",
+            "plugins/*/*.yaml",
+            "data/*.yaml",
+            "data/*.sh.in",
+            *list_testing_datafiles(),
+        ]
     },
     data_files=[
         # This is a weak attempt to integrate with the user nicely,
diff --git a/src/buildstream/py.typed b/src/buildstream/py.typed
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/src/buildstream/py.typed