[BUG](ci) Generate PySpark expressions before building the published wheel

[Seth Fitzsimmons (sethfitz)]

Fixes #625.

Problem

overture-schema-pyspark ships generated validation expressions that are not present in git; they are regenerated on demand from the Pydantic models. The publish workflow synced the workspace and ran uv build with no codegen step, so expressions/generated/ was absent on disk at build time and the wheel and sdist shipped without it. _registry.py walks that namespace at import, so an installed consumer gets an empty REGISTRY and validate_model() discovers no models. The build produced the empty wheel with no error.

Change

• Generate the expression tree (make generate-pyspark) in the publish workflow before uv build, gated to the overture-schema-pyspark matrix entry.
• Add a post-build guard: if the pyspark wheel contains no expressions/generated/*.py, abort the publish — a silent empty wheel becomes a loud failure.

Verification

Built the wheel and sdist locally under uv_build:

Path	generated in wheel	in sdist	guard
no generate step (current CI)	0	0	fires (aborts)
generate step (this PR)	all model modules	all	passes

The guard checks the wheel; uv build builds the wheel from the sdist, so a populated wheel confirms a populated sdist.

[github-actions]

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🕐 Updated	Jul 31, 2026 19:40 UTC
📝 Commit	0576be4
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[John McCall (lowlydba)]

suggestion (non-blocking): Seth Fitzsimmons (@sethfitz) what about moving the codegen into the build itself instead of the workflow? This shifts us from making per-package exceptions in the monorepo to letting each package own its configuration needs.

The root cause is that hatchling packages whatever is under src/overture at build time, so wheel contents depend on what ran before uv build. A hatchling build hook makes the wheel correct by construction:

[tool.hatch.build.targets.wheel.hooks.custom]
path = "hatch_build.py"

with a hook that runs codegen if expressions/generated/ is absent and fails the build if it comes up empty. Then any build path (this workflow, a local uv build, a consumer building from sdist) produces a complete wheel, and the guard lives inside the build where a new publish path can't skip it. The unzip -l check in YAML works, but it only protects this one workflow.

❗ Caveat: codegen imports the Pydantic models, so the hook needs overture-schema-system importable at build time. Either add it to build-system.requires or generate in the sdist hook only (CI has the workspace synced) and let wheels build from the populated sdist (feels trivial either way?)