🔧 mypy: enable strict type checking on src#795
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The mypy pre-commit hook excluded all of `src/`, so nothing was actually type-checked. Enable it: drop `src/.*` from the hook's exclude and add a strict `[tool.mypy]` config (`strict = true`). Strictness is enforced everywhere rather than ratcheted up flag by flag. The 17 modules that already pass are checked now; the 35 not yet annotated are listed under an `ignore_errors` override and get removed from that list one by one as they are typed. The global strictness is never relaxed to silence errors; the goal is to empty that list. Third-party deps without type information (node_graph, aiida_pythonjob, kiwipy, yaml, tabulate) are handled with `ignore_missing_imports`. Pin `mypy~=2.1.0` in the `pre-commit` extra so the hook environment provides it in CI; update the lockfile accordingly.
The mypy pre-commit hook excluded all of `src/`, so nothing was actually type-checked. Enable it: drop `src/.*` from the hook's exclude and add a strict `[tool.mypy]` config (`strict = true`). Strictness is enforced everywhere rather than ratcheted up flag by flag. The 17 modules that already pass are checked now; the 35 not yet annotated are listed under an `ignore_errors` override and get removed from that list one by one as they are typed. The global strictness is never relaxed to silence errors; the goal is to empty that list. On top of `strict`, enable several off-by-default error codes (`deprecated`, `exhaustive-match`, `mutable-override`, `possibly-undefined`, `redundant-self`, `truthy-iterable`, `unimported-reveal`, `unused-awaitable`); all pass on the checked modules. Third-party deps without type information (node_graph, aiida_pythonjob, kiwipy) are handled with `ignore_missing_imports`; yaml and tabulate are checked against the types-PyYAML and types-tabulate stubs in the `pre-commit` extra, pinned to match the runtime package versions. Run the hook with `language: system` so it uses the mypy from the activated dev/CI environment instead of building an isolated env that cannot import the project, and with `pass_filenames: false` against a fixed `files = ['src/aiida_workgraph']` target so every run checks the whole tree (an incremental commit can no longer miss a broken caller in an unchanged module). Pin `mypy~=2.1.0` in the `pre-commit` extra so that environment provides it, and update the lockfile accordingly.
elinscott
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Jun 25, 2026
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The mypy pre-commit hook excluded all of src/
... or, indeed, did not exist in the first place 🤦
I would also be in favour of a github test that runs mypy without the list of files to skip, just so we don't forget to eventually get that list down to zero.
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The mypy pre-commit hook excluded all of
src/, so nothing under it was ever actually type-checked. This turns it on with a strict config and gets the already-clean modules checked, without a big annotation push up front. The main decisions:strict = trueis enforced everywhere; modules that aren't annotated yet are parked in anignore_errorslist that shrinks one module at a time. Global strictness is never relaxed to silence errors, so the list only ever gets emptied (the opposite of ratcheting strictness up flag by flag).strict, a few off-by-default error codes are enabled (deprecated,possibly-undefined,mutable-override,truthy-iterable,exhaustive-match, etc.); all pass on the checked modules.yamlandtabulateare checked against real stubs (types-PyYAML,types-tabulate, pinned to the runtime package versions); the genuinely untyped deps (node_graph,aiida_pythonjob,kiwipy) stay onignore_missing_imports.language: systemandpass_filenames: falseagainst a fixedsrc/aiida_workgraphtarget, so a commit,pre-commit run --all-files, and a baremypyall check the whole tree (an incremental commit can't pass while breaking a caller in an unchanged module).mypyis pinned~=2.1.0in thepre-commitextra, matching aiida-core.explicit-overrideis left for a follow-up, since requiring@overridemeans a sweep across the existing class hierarchies.