fix(gallery): answer 400 for a missing or invalid image on the image-edit routes (#6818)

tests/test_gallery_image_bad_input.py

@@ -0,0 +1,44 @@
+import asyncio
+import base64
+import io
+
+import pytest
+from fastapi import HTTPException
+from PIL import Image
+
+import routes.gallery_routes as gallery
+
+ROUTES = ['sharpen', 'remove-bg', 'denoise', 'upscale-local', 'enhance-face']
+
+
+def route(name):
+    return next(r for r in gallery.setup_gallery_routes().routes if r.path == f'/api/image/{name}')
+
+
+def call(name, monkeypatch, body):
+    monkeypatch.setattr(gallery, 'require_privilege', lambda *args: 'alice')
+
+    class Request:
+        async def json(self):
+            return body
+
+    return asyncio.run(route(name).endpoint(Request()))
+
+
+@pytest.mark.parametrize('name', ROUTES)
+@pytest.mark.parametrize('body', [
+    {},
+    {'image': '!!notb64'},
+    {'image': base64.b64encode(b'hello').decode()},
+])
+def test_bad_image_is_a_client_error(name, body, monkeypatch):
+    with pytest.raises(HTTPException) as exc:
+        call(name, monkeypatch, body)
+    assert exc.value.status_code == 400
+
+
+def test_sharpen_still_accepts_a_valid_image(monkeypatch):
+    output = io.BytesIO()
+    Image.new('RGB', (4, 4), 'red').save(output, format='PNG')
+    result = call('sharpen', monkeypatch, {'image': base64.b64encode(output.getvalue()).decode()})
+    assert Image.open(io.BytesIO(base64.b64decode(result['image']))).size == (4, 4)