add mypy workflow (#41)

* add `mypy` workflow

* fix mypy errors

.github/workflows/mypy.yaml

@@ -0,0 +1,29 @@
+name: mypy
+
+on:
+  - push
+  - pull_request
+
+jobs:
+  mypy:
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version:
+          - "3.10"
+          - "3.12"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install mypy
+          pip install .
+      - name: Typecheck with mypy
+        run: |
+          mypy --ignore-missing-imports ocpsvg

ocpsvg/hlr.py

@@ -12,6 +12,7 @@
     Mapping,
     Optional,
     Sequence,
+    TypeAlias,
     Union,
 )
 from xml.etree import ElementTree as ET
@@ -38,16 +39,16 @@
 }
 
 
-Padding = Union[
+Padding: TypeAlias = Union[
     float,
     tuple[float],
     tuple[float, float],
     tuple[float, float, float],
     tuple[float, float, float, float],
 ]
-CssStyle = Mapping[str, Mapping[str, Any]]
-RGB = tuple[float, float, float]
-EdgeColor = Union[RGB, tuple[RGB, RGB]]
+CssStyle: TypeAlias = Mapping[str, Mapping[str, Any]]
+RGB: TypeAlias = tuple[float, float, float]
+EdgeColor: TypeAlias = Union[RGB, tuple[RGB, RGB]]
 
 
 PRIMARY_EDGES = "sharp", "outline"
@@ -253,12 +254,12 @@ def basic_style(
 ) -> CssStyle:
     if secondary_linewidth is None:
         secondary_linewidth = linewidth * 0.75
-    color, hidden_color = _edge_color_pair(color)
+    visible_color, hidden_color = _edge_color_pair(color)
 
-    style = {
+    style: dict[str, dict[str, Union[str, float]]] = {
         "path": {
             "fill": "none",
-            "stroke": hexcolor(color),
+            "stroke": hexcolor(visible_color),
             "stroke-width": linewidth,
             "stroke-linecap": "round",
             "stroke-linejoin": "round",
@@ -278,8 +279,8 @@ def basic_style(
 
     if shape_colors:
         for i, color in shape_colors.items():
-            color, hidden_color = _edge_color_pair(color)
-            style[f".s{i}"] = {"stroke": hexcolor(color)}
+            visible_color, hidden_color = _edge_color_pair(color)
+            style[f".s{i}"] = {"stroke": hexcolor(visible_color)}
             style[f".s{i}.hidden"] = {"stroke": hexcolor(hidden_color)}
 
     return style

ocpsvg/ocp.py

@@ -326,6 +326,7 @@ def circle_curve(
 ) -> Union[Geom_Circle, Geom_TrimmedCurve]:
     circle_gp = gp_Circ(gp_Ax2(gp_Pnt(), normal), radius)
 
+    circle: Union[Geom_Circle, Geom_TrimmedCurve]  # for mypy
     if start_angle == end_angle:
         circle = GC_MakeCircle(circle_gp).Value()
     else:
@@ -360,6 +361,7 @@ def ellipse_curve(
     ellipse_gp = gp_Elips(gp_Ax2(gp_Pnt(), normal), major_radius, minor_radius)
     ellipse_gp.Rotate(gp_Ax1(), radians(angle_adjustment))
 
+    ellipse: Union[Geom_Ellipse, Geom_TrimmedCurve]  # for mypy
     if start_angle == end_angle:
         ellipse = GC_MakeEllipse(ellipse_gp).Value()
     else:

ocpsvg/svg.py

@@ -13,6 +13,7 @@
     Optional,
     Sequence,
     TextIO,
+    TypeAlias,
     TypeVar,
     Union,
     overload,
@@ -109,11 +110,11 @@ def format_svg(path: Iterable[SvgPathCommand], float_format: str = "f") -> str:
     )
 
 
-SvgPathLike = Union[str, Iterable[SvgPathCommand], svgelements.Path]
-ShapeElement = svgelements.Shape
-ParentElement = Union[svgelements.Group, svgelements.Use]
+SvgPathLike: TypeAlias = Union[str, Iterable[SvgPathCommand], svgelements.Path]
+ShapeElement: TypeAlias = svgelements.Shape
+ParentElement: TypeAlias = Union[svgelements.Group, svgelements.Use]
 
-FaceOrWire = Union[TopoDS_Wire, TopoDS_Face]
+FaceOrWire: TypeAlias = Union[TopoDS_Wire, TopoDS_Face]
 
 
 class DocumentInfo(NamedTuple):
@@ -220,31 +221,31 @@ def process_wire(
             yield from wires
 
     if metadata:
-        wires_from_doc = wires_from_svg_document(
+        wires_from_doc_with_metadata = wires_from_svg_document(
             svg_file,
             ignore_visibility=ignore_visibility,
             metadata_factory=metadata,
         )
-        transform = doc_transform(wires_from_doc.doc_info)
+        transform = doc_transform(wires_from_doc_with_metadata.doc_info)
         items = (
-            (transform(face_or_wire), m)
-            for wires, is_filled, m in wires_from_doc
+            (transform(face_or_wire), metadata)
+            for wires, is_filled, metadata in wires_from_doc_with_metadata
             for face_or_wire in process_wire(wires, is_filled)
         )
-        return ItemsFromDocument(items, wires_from_doc.doc_info)
+        return ItemsFromDocument(items, wires_from_doc_with_metadata.doc_info)
     else:
-        wires_from_doc = wires_from_svg_document(
+        wires_from_doc_without_metadata = wires_from_svg_document(
             svg_file,
             ignore_visibility=ignore_visibility,
             metadata_factory=None,
         )
-        transform = doc_transform(wires_from_doc.doc_info)
+        transform = doc_transform(wires_from_doc_without_metadata.doc_info)
         items = (
             transform(face_or_wire)
-            for wires, is_filled, _metadata in wires_from_doc
+            for wires, is_filled, _metadata in wires_from_doc_without_metadata
             for face_or_wire in process_wire(wires, is_filled)
         )
-        return ItemsFromDocument(items, wires_from_doc.doc_info)
+        return ItemsFromDocument(items, wires_from_doc_without_metadata.doc_info)
 
 
 class ColorAndLabel:
@@ -274,6 +275,8 @@ def _color(
                 return tuple(float(v) / 255 for v in rgba)  # type: ignore
             except TypeError:
                 return 0, 0, 0, 1
+        else:
+            return None
 
     @staticmethod
     def _label(element: Union[ShapeElement, ParentElement], label_by: str):
@@ -312,6 +315,8 @@ def check_unskewed_transform() -> Union[tuple[float, float, float], None]:
         is_skewed = abs(o.angle_to(y) - o.angle_to(x)) != pi / 2  # type: ignore
         if not is_skewed:
             return o.distance_to(x), o.distance_to(y), o.angle_to(x)  # type: ignore
+        else:
+            return None
 
     element.reify()
 
@@ -325,11 +330,12 @@ def check_unskewed_transform() -> Union[tuple[float, float, float], None]:
         scale_x, scale_y, angle = scale_and_angle
         r1 = float(element.rx) * scale_x  # type: ignore
         r2 = float(element.ry) * scale_y  # type: ignore
-        if r1 == r2:
-            curve = circle_curve(r1, center=center)
-        else:
-            curve = ellipse_curve(r1, r2, center=center, rotation=degrees(angle))
-        yield wire_from_continuous_edges((edge_from_curve(curve),))
+        circle_or_ellpise = (
+            circle_curve(r1, center=center)
+            if r1 == r2
+            else ellipse_curve(r1, r2, center=center, rotation=degrees(angle))
+        )
+        yield wire_from_continuous_edges((edge_from_curve(circle_or_ellpise),))
 
     elif path := svg_element_to_path(element):
         yield from wires_from_svg_path(path)
@@ -503,7 +509,7 @@ def wire_to_svg_path(
     # but wires can be non-manifold or otherwise degenerate and may not have visit them all.
     # We'll add remaining edges individually
 
-    #TODO use a set if/when OCP implements `__eq__`
+    # TODO use a set if/when OCP implements `__eq__`
     all_edges = {hash(e): e for e in map(TopoDS.Edge_s, topoDS_iterator(wire))}
 
     if len(ordered_edges) < len(all_edges):
@@ -777,25 +783,25 @@ def is_filled(element: ShapeElement):
         return fill.value is not None  # type: ignore
 
     if callable(metadata_factory):
-        wires = (
+        wires_with_metadata = (
             (
                 list(wires_from_svg_element(source_element)),
                 is_filled(source_element),
                 metadata_factory(source_element, source_parents),
             )
             for source_element, source_parents in elements
         )
-        return ItemsFromDocument(wires, elements.doc_info)
+        return ItemsFromDocument(wires_with_metadata, elements.doc_info)
     else:
-        wires = (
+        wires_without_metadata = (
             (
                 list(wires_from_svg_element(source_element)),
                 is_filled(source_element),
                 None,
             )
             for source_element, _source_parents in elements
         )
-        return ItemsFromDocument(wires, elements.doc_info)
+        return ItemsFromDocument(wires_without_metadata, elements.doc_info)
 
 
 def find_shapes_svg_in_document(
@@ -806,7 +812,7 @@ def find_shapes_svg_in_document(
     def walk_svg_element(
         element: svgelements.SVGElement, parents: tuple[ParentElement, ...] = ()
     ) -> Iterator[tuple[ShapeElement, tuple[ParentElement, ...]]]:
-        if isinstance(element, ShapeElement):
+        if isinstance(element, svgelements.Shape):
             yield element, parents
         elif isinstance(element, (svgelements.Group, svgelements.Use)):
             new_parents = *parents, element