Bug: audio.play() Promise rejection unhandled in static JS, autoplay failures are silent

[anshul23102]

Bug Report: Unhandled audio.play() Promise Rejection Causes Silent Playback Failure

Description

The music player JavaScript calls audio.play() to start playback. In all
modern browsers, audio.play() returns a Promise that is rejected when the
browser's autoplay policy blocks playback (which happens for any page loaded
without prior user interaction). Without a .catch() handler, the rejection
becomes an unhandled promise rejection, and the user sees no error message,
spinner state, or indication that playback failed.

Steps to Reproduce

1. Open http://localhost:8000/ in Chrome or Firefox without any prior interaction.
2. Click the play button.
3. If autoplay is blocked, the play button appears to "work" but no audio plays.
4. Check the browser console: Uncaught (in promise) DOMException: play() failed.

Root Cause

audio.play();  // Missing .catch()

audio.play() returns a Promise. Without .catch(), any rejection
(autoplay policy, unsupported codec, network error) is swallowed silently.

Impact

Users on browsers with strict autoplay policies (all major browsers by default)
receive no feedback when playback fails, making the app appear broken.

Proposed Fix

Handle the rejection and show user feedback:

const playPromise = audio.play();
if (playPromise !== undefined) {
    playPromise
        .then(() => { updatePlayButton(true); })
        .catch(err => {
            console.warn("Playback failed:", err.message);
            updatePlayButton(false);
            showToast("Click anywhere on the page to enable audio playback.");
        });
}

[anshul23102]

@KDeekshita Hi! I came across this issue and I would love to work on it as part of GSSoC '26.

I have reviewed the problem description carefully and am confident I can deliver a well-tested, production-ready fix within the contribution timeline. Please let me know if you need any additional context or have specific implementation preferences before I get started.

Could you please assign this issue to me?

/assign
/claim