serenity/Tests/LibWeb/Text/input/input-file-accept.html

<input id="input1" type="file" accept="text/plain" />
<input id="input2" type="file" accept="text/plain" multiple />
<input id="input3" type="file" accept=".cpp" />
<input id="input4" type="file" accept=".cpp" multiple />
<script src="./include.js"></script>
<script type="text/javascript">
    const runTest = async id => {
        let input = document.getElementById(id);

        return new Promise(resolve => {
            input.addEventListener("input", async () => {
                println(`${id}:`);

                for (let file of input.files) {
                    const text = await file.text();
                    println(`${file.name}: ${file.type}: ${text}`);
                }

                resolve();
            });

            internals.dispatchUserActivatedEvent(input, new Event("mousedown"));
            input.showPicker();
        });
    };

    asyncTest(async done => {
        await runTest("input1");
        await runTest("input2");
        await runTest("input3");
        await runTest("input4");
        done();
    });
</script>