third_party/web_platform_tests/fetch/api/response/response-clone.html

<!doctype html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Response clone</title>
    <meta name="help" href="https://fetch.spec.whatwg.org/#response">
    <meta name="author" title="Canon Research France" href="https://www.crf.canon.fr">
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
  </head>
  <body>
    <script src="../resources/utils.js"></script>
    <script>
      var defaultValues = { "type" : "default",
                            "url" : "",
                            "ok" : true,
                            "status" : 200,
                            "statusText" : "OK"
      };

      var response = new Response();
      var clonedResponse = response.clone();
      test(function() {
        for (var attributeName in defaultValues) {
            var expectedValue = defaultValues[attributeName];
            assert_equals(clonedResponse[attributeName], expectedValue,
              "Expect default response." + attributeName + " is " + expectedValue);
        }
      }, "Check Response's clone with default values, without body");

      var body = "This is response body";
      var headersInit = { "name" : "value" };
      var responseInit  = { "status" : 200,
                            "statusText" : "GOOD",
                            "headers" : headersInit
      };
      var response = new Response(body, responseInit);
      var clonedResponse = response.clone();
      test(function() {
        assert_equals(clonedResponse.status, responseInit["status"],
          "Expect response.status is " + responseInit["status"]);
        assert_equals(clonedResponse.statusText, responseInit["statusText"],
          "Expect response.statusText is " + responseInit["statusText"]);
        assert_equals(clonedResponse.headers.get("name"), "value",
          "Expect response.headers has name:value header");
      }, "Check Response's clone has the expected attribute values");

      promise_test(function(test) {
        return validateStreamFromString(response.body.getReader(), body);
      }, "Check orginal response's body after cloning");

      promise_test(function(test) {
        return validateStreamFromString(clonedResponse.body.getReader(), body);
      }, "Check cloned response's body");

      promise_test(function(test) {
        var disturbedResponse = new Response("data");
        return disturbedResponse.text().then(function() {
            assert_true(disturbedResponse.bodyUsed, "response is disturbed");
            assert_throws(new TypeError() , function() { disturbedResponse.clone(); },
              "Expect TypeError exception");
        });
      }, "Cannot clone a disturbed response");

    promise_test(function(t) {
        var clone;
        var result;
        var response;
        return fetch('../resources/trickle.py?count=2&delay=100').then(function(res) {
            clone = res.clone();
            response = res;
            return clone.arrayBuffer();
        }).then(function(r) {
            assert_equals(r.byteLength, 26);
            result = r;
            return response.arrayBuffer();
        }).then(function(r) {
            assert_array_equals(r, result, "cloned responses should provide the same data");
        });
     }, 'Cloned responses should provide the same data');

    promise_test(function(t) {
        var clone;
        return fetch('../resources/trickle.py?count=2&delay=100').then(function(res) {
            clone = res.clone();
            res.body.cancel();
            assert_true(res.bodyUsed);
            assert_false(clone.bodyUsed);
            return clone.arrayBuffer();
        }).then(function(r) {
            assert_equals(r.byteLength, 26);
            assert_true(clone.bodyUsed);
        });
    }, 'Cancelling stream should not affect cloned one');

function testReadableStreamClone(initialBuffer, bufferType)
{
    promise_test(function(test) {
        var response = new Response(new ReadableStream({start : function(controller) {
            controller.enqueue(initialBuffer);
            controller.close();
        }}));

        var clone = response.clone();
        var stream1 = response.body;
        var stream2 = clone.body;

        var buffer;
        return stream1.getReader().read().then(function(data) {
            assert_false(data.done);
            assert_true(data.value === initialBuffer, "Buffer of being-cloned response stream is the same as the original buffer");
            return stream2.getReader().read();
        }).then(function(data) {
            assert_false(data.done);
            assert_array_equals(data.value, initialBuffer, "Cloned buffer chunks have the same content");
            assert_equals(Object.getPrototypeOf(data.value), Object.getPrototypeOf(initialBuffer), "Cloned buffers have the same type");
            if (ReadableStreamTee.length > 1) {
              // ReadableStreamTee supports cloning for stream2
              assert_true(data.value !== initialBuffer, "Buffer of cloned response stream is a clone of the original buffer");
            }
        });
    }, "Check response clone use structureClone for teed ReadableStreams (" + bufferType  + "chunk)");
}

var arrayBuffer = new ArrayBuffer(16);
testReadableStreamClone(new Int8Array(arrayBuffer, 1), "Int8Array");
testReadableStreamClone(new Int16Array(arrayBuffer, 2, 2), "Int16Array");
testReadableStreamClone(new Int32Array(arrayBuffer), "Int32Array");
testReadableStreamClone(arrayBuffer, "ArrayBuffer");
testReadableStreamClone(new Uint8Array(arrayBuffer), "Uint8Array");
testReadableStreamClone(new Uint8ClampedArray(arrayBuffer), "Uint8ClampedArray");
testReadableStreamClone(new Uint16Array(arrayBuffer, 2), "Uint16Array");
testReadableStreamClone(new Uint32Array(arrayBuffer), "Uint32Array");
testReadableStreamClone(new Float32Array(arrayBuffer), "Float32Array");
testReadableStreamClone(new Float64Array(arrayBuffer), "Float64Array");
testReadableStreamClone(new DataView(arrayBuffer, 2, 8), "DataView");
    </script>
  </body>
</html>