test(client): accelerate T-103 feedback loop

client/tests/device/test_sku_evidence_sanitizer.py

@@ -2,7 +2,9 @@
 
 from __future__ import annotations
 
+from functools import lru_cache
 from hashlib import sha256
+from io import BytesIO
 import json
 from pathlib import Path
 import sys
@@ -48,6 +50,16 @@ def _hash(path: Path) -> str:
     return digest.hexdigest()
 
 
+@lru_cache(maxsize=None)
+def _source_png(size: tuple[int, int]) -> bytes:
+    image = Image.new("RGB", size, color=(0, 180, 0))
+    if size == (EXPECTED_SCREENSHOT_WIDTH, EXPECTED_SCREENSHOT_HEIGHT):
+        image.paste((255, 0, 0), (0, 0, 8, 540))
+    output = BytesIO()
+    image.save(output, format="PNG")
+    return output.getvalue()
+
+
 def _default_xml() -> str:
     return (
         "<hierarchy rotation='0'>"
@@ -116,12 +128,7 @@ def _write_raw(
     raw = root / "raw"
     raw.mkdir(parents=True)
     screenshot = raw / "screenshot.png"
-    image = Image.new("RGB", size, color=(0, 180, 0))
-    if size == (EXPECTED_SCREENSHOT_WIDTH, EXPECTED_SCREENSHOT_HEIGHT):
-        for y in range(540):
-            for x in range(8):
-                image.putpixel((x, y), (255, 0, 0))
-    image.save(screenshot, format="PNG")
+    screenshot.write_bytes(_source_png(size))
     hierarchy = raw / "hierarchy.xml"
     hierarchy.write_text(_default_xml() if xml is None else xml, encoding="utf-8")
     manifest = {