big upgrade UwU

tests/conftest.py

@@ -0,0 +1,142 @@
+"""Test doubles for the Telegram bot and the CDN fetcher."""
+
+from __future__ import annotations
+
+import asyncio
+from dataclasses import dataclass, field
+from typing import Any
+
+import pytest
+from telegram.error import BadRequest
+
+from sticker_downloader.config import DownloadConfig
+
+
+@dataclass
+class FakeFile:
+    file_path: str
+
+
+@dataclass
+class FakeThumbnail:
+    file_id: str
+
+
+@dataclass
+class FakeSticker:
+    file_id: str
+    file_unique_id: str = "uniq"
+    emoji: str | None = "😀"
+    is_animated: bool = False
+    is_video: bool = False
+    thumbnail: FakeThumbnail | None = None
+    width: int = 512
+    height: int = 512
+    type: str = "regular"
+
+
+@dataclass
+class FakeStickerSet:
+    name: str
+    title: str = "A Pack"
+    sticker_type: str = "regular"
+    stickers: list[FakeSticker] = field(default_factory=list)
+    thumbnail: FakeThumbnail | None = None
+
+
+class FakeBot:
+    """Implements just the two coroutines the downloader calls."""
+
+    def __init__(
+        self,
+        sets: dict[str, FakeStickerSet] | None = None,
+        *,
+        extensions: dict[str, str] | None = None,
+    ) -> None:
+        self._sets = sets or {}
+        #: file_id -> extension served by the fake CDN URL.
+        self._extensions = extensions or {}
+        self.get_sticker_set_calls: list[str] = []
+        self.get_file_calls: list[str] = []
+
+    async def get_sticker_set(self, name: str) -> FakeStickerSet:
+        self.get_sticker_set_calls.append(name)
+        try:
+            return self._sets[name]
+        except KeyError:
+            raise BadRequest("Stickerset_invalid") from None
+
+    async def get_file(self, file_id: str) -> FakeFile:
+        self.get_file_calls.append(file_id)
+        extension = self._extensions.get(file_id, "webp")
+        return FakeFile(file_path=f"https://cdn.example/file/{file_id}.{extension}")
+
+
+class FakeFetcher:
+    """Returns deterministic bytes and can be told to fail for some URLs."""
+
+    def __init__(
+        self,
+        *,
+        payload: bytes = b"sticker-bytes",
+        failures: dict[str, Exception] | None = None,
+    ) -> None:
+        self._payload = payload
+        self._failures = failures or {}
+        self.urls: list[str] = []
+        self.max_concurrent = 0
+        self._in_flight = 0
+
+    async def fetch(self, url: str) -> bytes:
+        self.urls.append(url)
+        self._in_flight += 1
+        self.max_concurrent = max(self.max_concurrent, self._in_flight)
+        try:
+            await asyncio.sleep(0)
+            for needle, error in self._failures.items():
+                if needle in url:
+                    raise error
+            return self._payload
+        finally:
+            self._in_flight -= 1
+
+
+async def no_sleep(_delay: float) -> None:
+    """Drop-in for ``asyncio.sleep`` so retry tests run instantly."""
+    return None
+
+
+def make_sticker(index: int, **overrides: Any) -> FakeSticker:
+    """A static sticker with a PNG thumbnail, unless overridden."""
+    defaults: dict[str, Any] = {
+        "file_id": f"file{index}",
+        "file_unique_id": f"uniq{index}",
+        "thumbnail": FakeThumbnail(file_id=f"thumb{index}"),
+    }
+    defaults.update(overrides)
+    return FakeSticker(**defaults)
+
+
+@pytest.fixture
+def pack() -> FakeStickerSet:
+    return FakeStickerSet(
+        name="TestPack",
+        title="Test Pack",
+        stickers=[make_sticker(1), make_sticker(2)],
+        thumbnail=FakeThumbnail(file_id="packthumb"),
+    )
+
+
+@pytest.fixture
+def bot(pack: FakeStickerSet) -> FakeBot:
+    return FakeBot({pack.name: pack})
+
+
+@pytest.fixture
+def fetcher() -> FakeFetcher:
+    return FakeFetcher()
+
+
+@pytest.fixture
+def config(tmp_path) -> DownloadConfig:
+    return DownloadConfig(output_dir=tmp_path / "downloads")