buzz/crates/buzz-media/tests/fixtures/ios

UIKit media fixtures

These 2 x 2 fixtures were produced on an iOS simulator with UIKit, not by a generic image encoder.

Regeneration

1. Create a small source image and run this program against the simulator SDK:

   import Foundation
   import UIKit
   
   let arguments = CommandLine.arguments
   let source = try Data(contentsOf: URL(fileURLWithPath: arguments[1]))
   guard
     let image = UIImage(data: source),
     let png = image.pngData(),
     let jpeg = image.jpegData(compressionQuality: 1.0)
   else {
     fatalError("UIKit could not encode the source image")
   }
   try png.write(to: URL(fileURLWithPath: arguments[2]))
   try jpeg.write(to: URL(fileURLWithPath: arguments[3]))
   

   Compile and run it with the active Xcode toolchain:

   SDK_PATH="$(xcrun --sdk iphonesimulator --show-sdk-path)"
   xcrun --sdk iphonesimulator swiftc \
     -sdk "$SDK_PATH" \
     -target arm64-apple-ios16.0-simulator \
     reencode.swift -o reencode
   xcrun simctl spawn booted ./reencode \
     source.png uikit-encoded.png uikit-encoded.jpg
   

2. Copy the encoded files into both fixture directories:

   cp uikit-encoded.png mobile/ios/RunnerTests/Fixtures/UIKitEncoded.png
   cp uikit-encoded.jpg mobile/ios/RunnerTests/Fixtures/UIKitEncoded.jpg
   cp uikit-encoded.png crates/buzz-media/tests/fixtures/ios/
   cp uikit-encoded.jpg crates/buzz-media/tests/fixtures/ios/
   

3. Add a temporary Runner test that loads UIKitEncoded.png and UIKitEncoded.jpg, calls MediaSanitizer.scrubPng and MediaSanitizer.scrubJpeg, and writes those outputs to uikit-sanitized.png and uikit-sanitized.jpg. Run it once, copy the files here, then remove the temporary test.

4. Run cmp on each encoded copy to confirm that the Runner and Rust fixtures are byte-identical.

5. Run cargo test -p buzz-media test_ios_uikit to verify that UIKit's encoded output is rejected and the matching sanitizer output is accepted by the relay contract.

Regenerate both encoded and sanitized pairs whenever UIKit encoding or MediaSanitizer changes. Do not update only the sanitized files, because the test is intended to cover the exact encoder-to-sanitizer boundary.