Fix mypy2.1

.github/workflows/test.yml

@@ -39,6 +39,32 @@ jobs:
     - name: Run tests
       run: pytest
 
+  test-mypy-compat:
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        mypy-version:
+          - "~=1.3.0" # Lowest supported mypy version
+          - "~=1.19.1"
+          - "~=2.0.0"
+
+    steps:
+    - uses: actions/checkout@v6
+    - name: Set up Python
+      uses: actions/setup-python@v6
+      with:
+        # 3.11 is the highest Python supported by the lowest mypy in the matrix.
+        python-version: "3.11"
+    - name: Install dependencies
+      run: |
+        pip install -U pip setuptools wheel
+        pip install -e .
+        pip install -U "mypy${{ matrix.mypy-version }}"
+    - name: Run cache-cleanup tests
+      run: pytest pytest_mypy_plugins/tests/test_mypy_cache.py
+
   lint:
     runs-on: ubuntu-latest
 

pytest_mypy_plugins/configs.py

@@ -36,7 +36,7 @@ def join_toml_configs(
         # useful for overrides further.
         toml_config = tomlkit.document()
 
-    if "tool" not in toml_config or "mypy" not in toml_config["tool"]:  # type: ignore[operator]
+    if "tool" not in toml_config or "mypy" not in toml_config["tool"]:
         tool = tomlkit.table(is_super_table=True)
         tool.append("mypy", tomlkit.table())
         toml_config.append("tool", tool)
@@ -46,15 +46,15 @@ def join_toml_configs(
             additional_mypy_config = f"{_TOML_TABLE_NAME}\n{dedent(additional_mypy_config)}"
 
         additional_data = tomlkit.parse(additional_mypy_config)
-        toml_config["tool"]["mypy"].update(  # type: ignore[index, union-attr]
-            additional_data["tool"]["mypy"].value.items(),  # type: ignore[index]
+        toml_config["tool"]["mypy"].update(
+            additional_data["tool"]["mypy"].value.items(),
         )
 
     mypy_config_file_path = execution_path / "pyproject.toml"
     with mypy_config_file_path.open("w") as f:
         # We don't want the whole config file, because it can contain
         # other sections like `[tool.isort]`, we only need `[tool.mypy]` part.
-        tool_mypy = toml_config["tool"]["mypy"]  # type: ignore[index]
+        tool_mypy = toml_config["tool"]["mypy"]
 
         # construct toml output
         min_toml = tomlkit.document()

pytest_mypy_plugins/item.py

@@ -1,3 +1,4 @@
+import glob
 import importlib
 import io
 import os
@@ -374,7 +375,17 @@ def remove_cache_files(self, fpath_no_suffix: Path) -> None:
 
         # Build entry names to remove for each path component so namespace-package
         # cache entries are also cleaned (e.g. "pkg.*", "pkg/sub.*", "pkg/sub/mod.*").
-        suffixes = (".meta.json", ".data.json", ".err.json", ".meta.ff", ".data.ff", ".err.ff")
+        suffixes = (
+            ".meta.json",
+            ".data.json",
+            ".err.json",
+            ".meta.ff",
+            ".data.ff",
+            ".err.ff",
+            # mypy >= 2.0 also writes a `.meta_ex` companion file
+            ".meta_ex.json",
+            ".meta_ex.ff",
+        )
         entries: list[str] = []
         accumulated = ""
         for i, part in enumerate(fpath_no_suffix.parts):
@@ -388,7 +399,18 @@ def remove_cache_files(self, fpath_no_suffix: Path) -> None:
             entries.extend(accumulated + s for s in suffixes)
 
         stores: list[MetadataStore] = []
-        if os.path.isfile(os.path.join(cache_dir, "cache.db")):
+
+        # mypy >= 2.0 shards the sqlite cache across `cache.{i}.db` files instead of one `cache.db` file
+        # https://github.com/python/mypy/pull/21292
+        shard_dbs = glob.glob(os.path.join(cache_dir, "cache.*.db"))
+        if shard_dbs:
+            try:
+                # `num_shards` was added in mypy 2.0; pinned lint mypy is older.
+                stores.append(SqliteMetadataStore(cache_dir, num_shards=len(shard_dbs)))  # type: ignore[call-arg]
+            except TypeError:
+                # For backward compatibility with `SqliteMetadataStore` with no `num_shards` arg.
+                stores.append(SqliteMetadataStore(cache_dir))
+        elif os.path.isfile(os.path.join(cache_dir, "cache.db")):
             stores.append(SqliteMetadataStore(cache_dir))
         stores.append(FilesystemMetadataStore(cache_dir))
 

pytest_mypy_plugins/tests/test_mypy_cache.py

@@ -1,3 +1,5 @@
+import glob
+import os
 import subprocess
 from collections.abc import Generator
 from pathlib import Path
@@ -212,7 +214,15 @@ def make_yaml_test_file(
 def get_created_cache_files(cache_dir: Path, module_rel_paths_no_suffix: tuple[str, ...]) -> list[str]:
     stores: list[MetadataStore] = []
     cache_dir_str = str(cache_dir)
-    if (cache_dir / "cache.db").is_file():
+    # mypy >= 2.0 shards the sqlite cache across `cache.{i}.db` files instead of one `cache.db` file
+    shard_dbs = glob.glob(os.path.join(cache_dir_str, "cache.*.db"))
+    if shard_dbs:
+        try:
+            # `num_shards` was added in mypy 2.0; pinned lint mypy is older.
+            stores.append(SqliteMetadataStore(cache_dir_str, num_shards=len(shard_dbs)))  # type: ignore[call-arg]
+        except TypeError:
+            stores.append(SqliteMetadataStore(cache_dir_str))
+    elif (cache_dir / "cache.db").is_file():
         stores.append(SqliteMetadataStore(cache_dir_str))
     if cache_dir.is_dir():
         stores.append(FilesystemMetadataStore(cache_dir_str))
@@ -221,7 +231,7 @@ def get_created_cache_files(cache_dir: Path, module_rel_paths_no_suffix: tuple[s
     for store in stores:
         try:
             for entry in store.list_all():
-                if any(entry.startswith(rel_path + ".") for rel_path in module_rel_paths_no_suffix):
+                if any(os.path.normpath(entry).startswith(rel_path + ".") for rel_path in module_rel_paths_no_suffix):
                     created.append(entry)
         finally:
             # See PR #188: mypy < 1.20 does not have MetadataStore.close