chore: migrate from mypy to ty type checker (#63)

Replace mypy with Astral's ty, a faster Rust-based type checker.

- Update pyproject.toml config and dependencies
- Update pre-commit hook to use local ty via uvx
- Update CI workflow to run ty instead of mypy
- Fix type errors ty detected that mypy missed:
  - elevation_ft passed as string instead of int
  - Missing None checks before accessing seasonal_pattern.values()

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: dreamiurg

.github/workflows/ci.yml

@@ -54,8 +54,8 @@ jobs:
       - name: Run ruff format check
         run: uv run ruff format --check peakbagger tests
 
-      - name: Run mypy
-        run: uv run mypy peakbagger --pretty
+      - name: Run ty
+        run: uvx ty check peakbagger
         continue-on-error: true
 
   test:

.pre-commit-config.yaml

@@ -53,14 +53,15 @@ repos:
         additional_dependencies: ["bandit[toml]"]
         exclude: ^tests/
 
-  # Type checking with mypy
-  - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v1.18.2
+  # Type checking with ty
+  - repo: local
     hooks:
-      - id: mypy
-        additional_dependencies:
-          - types-requests
-        args: [--ignore-missing-imports, --python-version=3.12]
+      - id: ty
+        name: ty
+        entry: uvx ty check
+        language: system
+        types: [python]
+        pass_filenames: false
 
   # Markdown linting
   - repo: https://github.com/igorshubovych/markdownlint-cli

CLAUDE.md

@@ -314,7 +314,7 @@ Output changes include:
 - pytest + pytest-cov
 - ruff
 - pre-commit
-- mypy
+- ty
 - python-semantic-release
 - commitizen
 

pyproject.toml

@@ -37,8 +37,7 @@ dev = [
     "pytest-vcr>=1.0.2",
     "ruff>=0.8.0",
     "pre-commit>=3.0.0",
-    "mypy>=1.18.2",
-    "types-beautifulsoup4>=4.12.0.20250516",
+    "ty>=0.0.8",
     "vcrpy>=7.0.0",
 ]
 
@@ -94,12 +93,8 @@ python_files = "test_*.py"
 python_functions = "test_*"
 addopts = "-v --cov=peakbagger --cov-report=term-missing"
 
-[tool.mypy]
-python_version = "3.12"
-warn_return_any = true
-warn_unused_configs = true
-disallow_untyped_defs = false
-ignore_missing_imports = true
+[tool.ty.environment]
+python-version = "3.12"
 
 [tool.semantic_release]
 version_toml = ["pyproject.toml:project.version"]
@@ -132,12 +127,11 @@ tag_format = "$version"
 [dependency-groups]
 dev = [
     "commitizen>=4.9.1",
-    "mypy>=1.18.2",
     "pre-commit>=4.3.0",
     "pytest-cov>=7.0.0",
     "pytest-vcr>=1.0.2",
     "python-semantic-release>=10.4.1",
     "twine>=6.2.0",
-    "types-beautifulsoup4>=4.12.0.20250516",
+    "ty>=0.0.8",
     "vcrpy>=7.0.0",
 ]

tests/test_cli_errors.py

@@ -134,7 +134,7 @@ def test_search_full_flag_with_empty_peaks(self):
                     name="Test Peak",
                     url="peak.aspx?pid=1",
                     pid="1",
-                    elevation_ft="1000",
+                    elevation_ft=1000,
                     location="USA",
                 )
             ]

tests/test_statistics.py

@@ -166,6 +166,8 @@ def test_calculate_statistics_seasonal_window(self, sample_ascents):
         )
 
         # Wide window should capture more ascents in seasonal pattern
+        assert stats_wide.seasonal_pattern is not None
+        assert stats_narrow.seasonal_pattern is not None
         assert sum(stats_wide.seasonal_pattern.values()) >= sum(
             stats_narrow.seasonal_pattern.values()
         )
@@ -183,6 +185,7 @@ def test_calculate_statistics_year_wraparound(self):
         )
 
         # Both ascents should be within seasonal window due to wraparound handling
+        assert stats.seasonal_pattern is not None
         assert sum(stats.seasonal_pattern.values()) >= 1
 
     def test_calculate_statistics_invalid_date_formats(self):
@@ -465,4 +468,5 @@ def test_large_seasonal_window(self):
         )
 
         # With 365-day window, all ascents should be in seasonal pattern
+        assert stats.seasonal_pattern is not None
         assert sum(stats.seasonal_pattern.values()) == 12