message: Display formatted output for JSON diffing in tests.
diff: @@ -75,8 +75,10 @@ fn _validate_upload(
  f.read_exact(&mut json_bytes).expect("read JSON data");
  let actual_json = serde_json::from_slice(&json_bytes).expect("uploaded JSON should be valid");
  let expected_json = serde_json::from_str(expected_json).expect("expected JSON does not parse");
  - find_json_mismatch(&expected_json, &actual_json)
  - .expect("uploaded JSON did not match expected JSON");
  +
  + if let Err(e) = find_json_mismatch(&expected_json, &actual_json) {
  + panic!("{}", e);
  + }
  // 32-bit little-endian integer of length of crate file.
  let crate_sz = read_le_u32(&mut f).expect("read crate length");
  