Enable strict type checking with mypy

- Update mypy configuration with stricter type checking rules
- Add more type stubs to pre-commit configuration
- Run mypy both through pre-commit and directly in CI
- Install project in editable mode for better type checking
- Set correct PYTHONPATH in CI environment

.github/workflows/lint.yml

@@ -51,8 +51,20 @@ jobs:
           cache: 'pip'
       - name: Install pre-commit
         run: pip install pre-commit==3.7.0
+      - name: Install project in editable mode
+        run: pip install -e .
       - name: Run pre-commit hooks
         run: pre-commit run --files openhands/**/* evaluation/**/* tests/**/* --show-diff-on-failure --config ./dev_config/python/.pre-commit-config.yaml
+      - name: Run mypy directly (for better error reporting)
+        if: always()  # Run even if pre-commit fails
+        run: |
+          pip install mypy==1.9.0 \
+            types-requests types-setuptools types-pyyaml types-toml \
+            types-redis types-protobuf types-python-dateutil types-pyjwt \
+            types-docutils types-Pillow types-boto3 types-cryptography \
+            types-Jinja2 types-MarkupSafe types-click types-filelock \
+            types-decorator types-docopt types-emoji types-enum34 types-paramiko
+          PYTHONPATH=$PWD mypy --config-file dev_config/python/mypy.ini --scripts-are-modules openhands/
 
   # Check version consistency across documentation
   check-version-consistency:

dev_config/python/.pre-commit-config.yaml

@@ -36,8 +36,30 @@ repos:
     rev: v1.9.0
     hooks:
       - id: mypy
+        name: mypy (with strict type checking)
         additional_dependencies:
-          [types-requests, types-setuptools, types-pyyaml, types-toml]
-        entry: mypy --config-file dev_config/python/mypy.ini openhands/
+          - types-requests
+          - types-setuptools
+          - types-pyyaml
+          - types-toml
+          - types-redis
+          - types-protobuf
+          - types-python-dateutil
+          - types-pyjwt
+          - types-docutils
+          - types-Pillow
+          - types-boto3
+          - types-cryptography
+          - types-Jinja2
+          - types-MarkupSafe
+          - types-click
+          - types-filelock
+          - types-decorator
+          - types-docopt
+          - types-emoji
+          - types-enum34
+          - types-paramiko
+        entry: mypy --config-file dev_config/python/mypy.ini --scripts-are-modules openhands/
         always_run: true
         pass_filenames: false
+        verbose: true

dev_config/python/mypy.ini

@@ -1,9 +1,29 @@
 [mypy]
-warn_unused_configs = True
+# Error output
+show_error_codes = True
+pretty = True
+show_column_numbers = True
+
+# Import discovery
 ignore_missing_imports = True
+follow_imports = normal
+
+# Untyped definitions and calls
+disallow_untyped_defs = True
 check_untyped_defs = True
-explicit_package_bases = True
-warn_unreachable = True
-warn_redundant_casts = True
+disallow_incomplete_defs = True
+disallow_untyped_decorators = True
+
+# None and Optional handling
 no_implicit_optional = True
 strict_optional = True
+
+# Warnings
+warn_unused_configs = True
+warn_redundant_casts = True
+warn_unused_ignores = True
+warn_return_any = True
+warn_unreachable = True
+
+# Misc
+explicit_package_bases = True