More mypy (#451)

* Fix: Correct more mypy errors.

* Add: Run type checks on each commit.

* Fix: mypy failure on Python 3.8.

Author: bjones1

.github/workflows/test-on-push.yml

@@ -78,6 +78,10 @@ jobs:
         python -m poetry run python scripts/fetch_core.py
         python -m poetry run python scripts/zip_templates.py
 
+    - name: Check types
+      run: |
+        python -m poetry run mypy --install-types --non-interactive
+
     - name: Test with pytest
       run: |
         python -m poetry run pytest -v --cov

pretext/generate.py

@@ -22,7 +22,7 @@ def latex_image(
     all_formats: bool = False,
 ) -> None:
     # Dictionary of formats for images based on target
-    formats = {
+    formats: Dict[str, List[str]] = {
         "pdf": [],
         "latex": [],
         "html": ["svg"],
@@ -43,7 +43,7 @@ def latex_image(
             li := source_xml.xpath("/pretext/*[not(docinfo)]//latex-image"), List
         )
         and len(li) > 0
-        and formats[target_format] is not None
+        and formats[target_format] != []
     ):
         image_output = (output / "latex-image").resolve()
         os.makedirs(image_output, exist_ok=True)
@@ -159,7 +159,7 @@ def asymptote(
     }
     # set overwrite formats to all when appropriate
     if all_formats:
-        formats[target_format] = {key: ["all"] for key in formats[target_format]}
+        formats[target_format] = ["all"]
     # We assume passed paths are absolute.
     # parse source so we can check for asymptote.
     source_xml = ET.parse(ptxfile)

pretext/templates/__init__.py

@@ -14,6 +14,7 @@ def resource_path(filename: str) -> AbstractContextManager:
     # Try except here is to use newer importlib function,
     # supported starting with 3.9, and required with 3.11
     try:
-        return ir.as_file(ir.files(resources).joinpath(filename))
+        # TODO: remove the ignore when Python 3.8 support ends. This fails Python 3.8 type checks, since these functions depend on newer Python versions.
+        return ir.as_file(ir.files(resources).joinpath(filename))  # type: ignore[attr-defined]
     except AttributeError:
         return ir.path(resources, filename)

pyproject.toml

@@ -80,7 +80,7 @@ script_launch_mode = "subprocess"
 [tool.mypy]
 # See `files <https://mypy.readthedocs.io/en/stable/config_file.html#confval-files>`_.
 files = "pretext"
-exclude = "^pretext/core/pretext.py"
+exclude = "^pretext/core/pretext\\.py$"
 check_untyped_defs = true
 disallow_untyped_defs = true