Refactor + strictly-type image component (#81808)

* image: refactor size validation to use partition

* image: give _generate_thumbnail types and use partition

* image: become strictly typed

.strict-typing

@@ -151,6 +151,7 @@ homeassistant.components.http.*
 homeassistant.components.huawei_lte.*
 homeassistant.components.hyperion.*
 homeassistant.components.ibeacon.*
+homeassistant.components.image.*
 homeassistant.components.image_processing.*
 homeassistant.components.input_button.*
 homeassistant.components.input_select.*

homeassistant/components/image/__init__.py

@@ -6,6 +6,7 @@ import logging
 import pathlib
 import secrets
 import shutil
+from typing import Any
 
 from PIL import Image, ImageOps, UnidentifiedImageError
 from aiohttp import hdrs, web
@@ -71,7 +72,7 @@ class ImageStorageCollection(collection.StorageCollection):
         self.async_add_listener(self._change_listener)
         self.image_dir = image_dir
 
-    async def _process_create_data(self, data: dict) -> dict:
+    async def _process_create_data(self, data: dict[str, Any]) -> dict[str, Any]:
         """Validate the config is valid."""
         data = self.CREATE_SCHEMA(dict(data))
         uploaded_file: FileField = data["file"]
@@ -88,7 +89,7 @@ class ImageStorageCollection(collection.StorageCollection):
 
         return data
 
-    def _move_data(self, data):
+    def _move_data(self, data: dict[str, Any]) -> int:
         """Move data."""
         uploaded_file: FileField = data.pop("file")
 
@@ -119,15 +120,24 @@ class ImageStorageCollection(collection.StorageCollection):
         return media_file.stat().st_size
 
     @callback
-    def _get_suggested_id(self, info: dict) -> str:
+    def _get_suggested_id(self, info: dict[str, Any]) -> str:
         """Suggest an ID based on the config."""
-        return info[CONF_ID]
+        return str(info[CONF_ID])
 
-    async def _update_data(self, data: dict, update_data: dict) -> dict:
+    async def _update_data(
+        self,
+        data: dict[str, Any],
+        update_data: dict[str, Any],
+    ) -> dict[str, Any]:
         """Return a new updated data object."""
         return {**data, **self.UPDATE_SCHEMA(update_data)}
 
-    async def _change_listener(self, change_type, item_id, data):
+    async def _change_listener(
+        self,
+        change_type: str,
+        item_id: str,
+        data: dict[str, Any],
+    ) -> None:
         """Handle change."""
         if change_type != collection.CHANGE_REMOVED:
             return
@@ -141,7 +151,7 @@ class ImageUploadView(HomeAssistantView):
     url = "/api/image/upload"
     name = "api:image:upload"
 
-    async def post(self, request):
+    async def post(self, request: web.Request) -> web.Response:
         """Handle upload."""
         # Increase max payload
         request._client_max_size = MAX_SIZE  # pylint: disable=protected-access
@@ -159,26 +169,27 @@ class ImageServeView(HomeAssistantView):
     requires_auth = False
 
     def __init__(
-        self, image_folder: pathlib.Path, image_collection: ImageStorageCollection
+        self,
+        image_folder: pathlib.Path,
+        image_collection: ImageStorageCollection,
     ) -> None:
         """Initialize image serve view."""
         self.transform_lock = asyncio.Lock()
         self.image_folder = image_folder
         self.image_collection = image_collection
 
-    async def get(self, request: web.Request, image_id: str, filename: str):
+    async def get(
+        self,
+        request: web.Request,
+        image_id: str,
+        filename: str,
+    ) -> web.FileResponse:
         """Serve image."""
-        image_size = filename.split("-", 1)[0]
         try:
-            parts = image_size.split("x", 1)
-            width = int(parts[0])
-            height = int(parts[1])
+            width, height = _validate_size_from_filename(filename)
         except (ValueError, IndexError) as err:
             raise web.HTTPBadRequest from err
 
-        if not width or width != height or width not in VALID_SIZES:
-            raise web.HTTPBadRequest
-
         image_info = self.image_collection.data.get(image_id)
 
         if image_info is None:
@@ -205,8 +216,33 @@ class ImageServeView(HomeAssistantView):
         )
 
 
-def _generate_thumbnail(original_path, content_type, target_path, target_size):
+def _generate_thumbnail(
+    original_path: pathlib.Path,
+    content_type: str,
+    target_path: pathlib.Path,
+    target_size: tuple[int, int],
+) -> None:
     """Generate a size."""
     image = ImageOps.exif_transpose(Image.open(original_path))
     image.thumbnail(target_size)
-    image.save(target_path, format=content_type.split("/", 1)[1])
+    image.save(target_path, format=content_type.partition("/")[-1])
+
+
+def _validate_size_from_filename(filename: str) -> tuple[int, int]:
+    """Parse image size from the given filename (of the form WIDTHxHEIGHT-filename).
+
+    >>> _validate_size_from_filename("100x100-image.png")
+    (100, 100)
+    >>> _validate_size_from_filename("jeff.png")
+    Traceback (most recent call last):
+    ...
+    """
+    image_size = filename.partition("-")[0]
+    if not image_size:
+        raise ValueError("Invalid filename")
+    width_s, _, height_s = image_size.partition("x")
+    width = int(width_s)
+    height = int(height_s)
+    if not width or width != height or width not in VALID_SIZES:
+        raise ValueError(f"Invalid size {image_size}")
+    return (width, height)

mypy.ini

@@ -1263,6 +1263,16 @@ disallow_untyped_defs = true
 warn_return_any = true
 warn_unreachable = true
 
+[mypy-homeassistant.components.image.*]
+check_untyped_defs = true
+disallow_incomplete_defs = true
+disallow_subclassing_any = true
+disallow_untyped_calls = true
+disallow_untyped_decorators = true
+disallow_untyped_defs = true
+warn_return_any = true
+warn_unreachable = true
+
 [mypy-homeassistant.components.image_processing.*]
 check_untyped_defs = true
 disallow_incomplete_defs = true