pre-commit mypy config (#106)

Author: evertlammerts

.github/workflows/code_quality.yml

@@ -19,7 +19,7 @@ defaults:
 
 jobs:
   run_checks:
-    name: Run linting and formatting
+    name: Run linting, formatting and static type checker
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4

.pre-commit-config.yaml

@@ -1,15 +1,15 @@
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
-    rev: v0.13.0
+    rev: v0.13.3
     hooks:
       # Run the linter.
       - id: ruff-check
       # Run the formatter.
       - id: ruff-format
 
   - repo: https://github.com/pre-commit/mirrors-clang-format
-    rev: v18.1.8    # pick the version of clang-format you want
+    rev: v21.1.2    # pick the version of clang-format you want
     hooks:
       - id: clang-format
         files: \.(c|cpp|cc|h|hpp|cxx|hxx)$
@@ -19,6 +19,15 @@ repos:
     hooks:
       - id: cmake-format
 
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v1.18.2
+    hooks:
+      - id: mypy
+        entry: mypy -v
+        files: ^(duckdb/|_duckdb-stubs/)
+        exclude: ^duckdb/(experimental|query_graph)/
+        additional_dependencies: [ numpy, polars ]
+
   - repo: local
     hooks:
       - id: post-checkout-submodules

duckdb/polars_io.py

@@ -277,8 +277,8 @@ def source_generator(
         for record_batch in iter(results.read_next_batch, None):
             if predicate is not None and duck_predicate is None:
                 # We have a predicate, but did not manage to push it down, we fallback here
-                yield pl.from_arrow(record_batch).filter(predicate)  # type: ignore[arg-type,misc]
+                yield pl.from_arrow(record_batch).filter(predicate)  # type: ignore[arg-type,misc,unused-ignore]
             else:
-                yield pl.from_arrow(record_batch)  # type: ignore[misc]
+                yield pl.from_arrow(record_batch)  # type: ignore[misc,unused-ignore]
 
     return register_io_source(source_generator, schema=schema)

pyproject.toml

@@ -323,6 +323,7 @@ python_version = "3.9"
 exclude = [
     "duckdb/experimental/", # not checking the pyspark API
     "duckdb/query_graph/",  # old and unmaintained (should probably remove)
+    "tests", "scripts",
 ]
 
 [[tool.mypy.overrides]]