<script>

    var bytesRead = 0;

    function recursiveRead(reader) {
        reader.read().then(function({ done, value }) {
            for (var i = 0; i < value.length; i++) {
                alert("RECEIVED BYTE '" + String.fromCharCode(value[i]) + "'");
                bytesRead = bytesRead + 1;
            }
            if (bytesRead == 4) {
                if (window.testRunner) {
                    testRunner.notifyDone();
                }
            } else {
                recursiveRead(reader);
            }
        });
    }
    
    function runTest() {
        let fileBits = [
            'a',
            new File([], 'x'),
            'b',
            new File([], 'x'),
            'c',
            new File([], 'x'),
            'd'
        ];
        let file = new File(fileBits, 'y');
        recursiveRead(file.stream().getReader());
    }

    if (window.testRunner) {
        testRunner.dumpAsText();
        testRunner.waitUntilDone();
    }

</script>
<body onload="runTest()">
</body>