<script>
    if (window.testRunner) {
        testRunner.waitUntilDone();
        testRunner.dumpAsText();
    }
    async function readUntilError(stream) {
        const reader = stream.getReader();
        try {
            let read_value = await reader.read();
            if (window.testRunner && window.testRunner.terminateNetworkProcess) {
                alert("FAIL - successfully read from stream");
            } else {
                // WebKitLegacy can't terminate the network process.
                alert("PASS");
            }
            if (window.testRunner) {
                testRunner.notifyDone();
            }
        } catch (e) {
            if (window.testRunner && window.testRunner.terminateNetworkProcess) {
                alert("PASS");
            } else {
                alert("FAIL - error without terminating network process");
            }
            if (window.testRunner) {
                testRunner.notifyDone();
            }
        }
    }
    var b = new Blob([1, 2, 3]);
    if (window.testRunner && window.testRunner.terminateNetworkProcess) {
        testRunner.terminateNetworkProcess();
    }
    readUntilError(b.stream());
</script>