gecko-dev/dom/xhr/tests/browser_temporaryFile.js

add_task(async _ => {
  await new Promise(resolve => {
    var xhr = new XMLHttpRequest();
    xhr.open("POST", "http://mochi.test:8888/browser/dom/xhr/tests/temporaryFileBlob.sjs");
    xhr.responseType = 'blob';
    xhr.send("");
    xhr.onloadend = _ => {
      is(xhr.response.blobImplType, "EmptyBlobImpl", "We want a EmptyBlobImpl");
      resolve();
    }
  });
});

add_task(async _ => {
  var data = new Array(2).join("1234567890ABCDEF");

  await new Promise(resolve => {
    var xhr = new XMLHttpRequest();
    xhr.open("POST", "http://mochi.test:8888/browser/dom/xhr/tests/temporaryFileBlob.sjs");
    xhr.responseType = 'blob';
    xhr.send({toString: function() { return data; }});
    xhr.onloadend = _ => {
      is(xhr.response.blobImplType, "MemoryBlobImpl", "We want a MemoryBlobImpl");
      resolve();
    }
  });
});

add_task(async _ => {
  await SpecialPowers.pushPrefEnv({ "set" : [[ "dom.blob.memoryToTemporaryFile", 1 ]] });

  var data = new Array(2).join("1234567890ABCDEF");

  await new Promise(resolve => {
    var xhr = new XMLHttpRequest();
    xhr.open("POST", "http://mochi.test:8888/browser/dom/xhr/tests/temporaryFileBlob.sjs");
    xhr.responseType = 'blob';
    xhr.send({toString: function() { return data; }});
    xhr.onloadend = _ => {
      is(xhr.response.blobImplType, "StreamBlobImpl[TemporaryBlobImpl]", "We want a StreamBlobImpl holding a TemporaryBlobImpl on the parent side");
      resolve();
    }
  });
});