feat: Validate compressor quality range and fail fast

Author: vdusek

src/apify_client/http_compressors/_brotli.py

@@ -13,14 +13,25 @@ class BrotliHttpCompressor(HttpCompressor):
 
     content_encoding = 'br'
 
+    _min_quality = 0
+    """Lowest valid quality (fastest, least compression)."""
+
+    _max_quality = 11
+    """Highest valid quality (slowest, best compression)."""
+
     def __init__(self, *, quality: int = 6) -> None:
         """Initialize the brotli compressor.
 
         Args:
-            quality: Compression level, `0` (fastest) to `11` (the best compression). Defaults to `6`,
-                a reasonable compromise between speed and compression ratio. Passed straight to the
-                `brotli` module, which validates it.
+            quality: Compression level, from the fastest to the best compression.
+
+        Raises:
+            ValueError: If `quality` is out of the valid range.
         """
+        if not self._min_quality <= quality <= self._max_quality:
+            raise ValueError(
+                f'brotli quality must be between {self._min_quality} and {self._max_quality}, got {quality}.'
+            )
         self._quality = quality
 
     def compress(self, data: bytes) -> bytes:

src/apify_client/http_compressors/_gzip.py

@@ -13,13 +13,25 @@ class GzipHttpCompressor(HttpCompressor):
 
     content_encoding = 'gzip'
 
-    def __init__(self, *, quality: int = 9) -> None:
+    _min_quality = 1
+    """Lowest valid quality (fastest, least compression)."""
+
+    _max_quality = 9
+    """Highest valid quality (slowest, best compression)."""
+
+    def __init__(self, *, quality: int = _max_quality) -> None:
         """Initialize the gzip compressor.
 
         Args:
-            quality: Compression level, `1` (fastest) to `9` (the best compression). Defaults to `9`.
-                Passed straight to the `gzip` module, which validates it.
+            quality: Compression level, from the fastest to the best compression.
+
+        Raises:
+            ValueError: If `quality` is out of the valid range.
         """
+        if not self._min_quality <= quality <= self._max_quality:
+            raise ValueError(
+                f'gzip quality must be between {self._min_quality} and {self._max_quality}, got {quality}.'
+            )
         self._quality = quality
 
     def compress(self, data: bytes) -> bytes:

tests/unit/test_http_compressors.py

@@ -60,6 +60,20 @@ def test_brotli_compressor_round_trips_at_quality(quality: int) -> None:
     assert brotli.decompress(BrotliHttpCompressor(quality=quality).compress(b'payload')) == b'payload'
 
 
+@pytest.mark.parametrize('quality', [0, 10, -1])
+def test_gzip_compressor_rejects_out_of_range_quality(quality: int) -> None:
+    """Gzip compressor raises `ValueError` at construction for a quality not between `1` and `9`."""
+    with pytest.raises(ValueError, match='gzip quality must be between 1 and 9'):
+        GzipHttpCompressor(quality=quality)
+
+
+@pytest.mark.parametrize('quality', [-1, 12])
+def test_brotli_compressor_rejects_out_of_range_quality(quality: int) -> None:
+    """Brotli compressor raises `ValueError` at construction for a quality not between `0` and `11`."""
+    with pytest.raises(ValueError, match='brotli quality must be between 0 and 11'):
+        BrotliHttpCompressor(quality=quality)
+
+
 def test_gzip_compressor_round_trips_and_sets_content_encoding() -> None:
     """Gzip compressor round-trips data and reports `gzip` as its content encoding."""
     compressor = GzipHttpCompressor()