ci: fix scss build on building

We add a custom hook to our sdist target, such that "make scss" is run
whenever we run `python -m build --sdist`.

.gitlab-ci.yml

@@ -3,11 +3,6 @@ variables:
   TUTOR_PYPI_PACKAGE: tutor-deck
   GITHUB_REPO: overhangio/tutor-deck
 
-build-css:
-  script:
-    - make scss
-  stage: build
-
 include:
   - project: "community/tutor-ci"
     file: "plugin-gitlab-ci.yml"

.hatch_build.py

@@ -1,12 +1,20 @@
 # https://hatch.pypa.io/latest/how-to/config/dynamic-metadata/
 import os
+import subprocess
 import typing as t
 
+from hatchling.builders.hooks.plugin.interface import BuildHookInterface
 from hatchling.metadata.plugin.interface import MetadataHookInterface
 
 HERE = os.path.dirname(__file__)
 
 
+class CustomBuildHook(BuildHookInterface):
+    def initialize(self, version, build_data):
+        # This runs before the build starts
+        subprocess.check_call(["make", "scss"])
+
+
 class MetaDataHook(MetadataHookInterface):
     def update(self, metadata: dict[str, t.Any]) -> None:
         about = load_about()

pyproject.toml

@@ -69,5 +69,9 @@ strict-naming = false
 include = [ "/tutordeck", ".hatch_build.py"]
 exclude = ["tests*"]
 
+[tool.hatch.build.targets.sdist.hooks.custom]
+# Build static assets prior to running sdist
+path = ".hatch_build.py"
+
 [tool.hatch.build.targets.wheel]
 packages = ["tutordeck"]