fix typing in decl-param plus upgraded versions of workflow actions (#9)

* fix typing in `decl-param.py`
* upgraded versions of workflow action

Author: vassilyl

.github/workflows/CI.yml

@@ -17,9 +17,9 @@ jobs:
         python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12-dev']
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
@@ -43,7 +43,7 @@ jobs:
       run: |
         pytest --junitxml=junit/test-results-${{ matrix.python-version }}.xml --cov=msrc.appconfig --cov=msrc.appconfig_decl --cov-report=xml --cov-report=html
     - name: Upload pytest test results
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v3
       with:
         name: pytest-results-${{ matrix.python-version }}
         path: |

msrc-appconfig-param/msrc/appconfig_decl/decl_param.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 from msrc.appconfig.schema import (
     Element, AtomicType, TupleType, Schema, SchemaSource)
-from typing import Optional, Tuple, Union, Type, cast
+from typing import Optional, Tuple, Union, Type, Any, cast
 import param
 import enum
 
@@ -14,8 +14,8 @@ class IntTuple(param.NumericTuple):
     def _validate(self, val: object):
         super()._validate(val)
         # NumeriTuple ensures val is a numeric tuple
-        val = cast(Tuple[object, ...], val)
         if val is not None:
+            val = cast(Tuple[object, ...], val)
             for i, n in enumerate(val):
                 if not isinstance(n, int):
                     raise ValueError(
@@ -55,7 +55,9 @@ def make_element(
             t = TupleType(AtomicType.INT, f.length)
         elif isinstance(f, param.NumericTuple):
             t = TupleType(AtomicType.FLOAT, f.length)
-        elif isinstance(f, param.List) and f.class_ is None:
+        # pyright 1.1.292 inference makes param.List.class_ be Type[object]
+        # which is incorrect.
+        elif isinstance(f, param.List) and cast(Any, f.class_) is None:
             raise ValueError("List parameter %s doesn't specify type of "
                              "list items using class_ keyword.")
         elif isinstance(f, param.List) and issubclass(f.class_, bool):