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fix: <vimeo-video> element race condition #220

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fix: <vimeo-video> element race condition #220

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14be2eb
refactored load function for readability
spuppo-mux Mar 20, 2026
6a8f3dc
Moved load decoupling to the top of the function
spuppo-mux Mar 20, 2026
50ef896
Added state cleanup on disconnect
spuppo-mux Mar 20, 2026
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80 changes: 44 additions & 36 deletions packages/vimeo-video-element/vimeo-video-element.js
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Original file line number Diff line number Diff line change
Expand Up @@ -138,17 +138,16 @@ class VimeoVideoElement extends MediaPlayedRangesMixin(globalThis.HTMLElement ??
}

async load() {
if (this.#loadRequested) return;

const isFirstLoad = !this.#hasLoaded;

if (this.#hasLoaded) this.loadComplete = new PublicPromise();
this.#hasLoaded = true;
if (this.#loadRequested) return;

// Wait 1 tick to allow other attributes to be set.
await (this.#loadRequested = Promise.resolve());
this.#loadRequested = null;

if (this.#hasLoaded) this.loadComplete = new PublicPromise();
this.#hasLoaded = true; // TODO: Identify how hasLoaded differs from isInit
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@cursor cursor bot Mar 24, 2026

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Reordered loadComplete refresh enables null api dereference

Medium Severity

Moving if (this.#hasLoaded) this.loadComplete = new PublicPromise() from before the 1-tick await to after it introduces a timing regression on second+ loads. When src and loop change in the same synchronous block (common in React/Next.js), the loop handler's await this.loadComplete resolves immediately on the stale promise. Its continuation then runs after load() sets this.api = null, causing this.api.setLoop(...) to throw a TypeError. Previously, loadComplete was refreshed before the await, so the loop handler would correctly suspend until the new load completed.

Additional Locations (1)
Fix in Cursor Fix in Web


this.#currentTime = 0;
this.#duration = NaN;
this.#muted = false;
Expand Down Expand Up @@ -185,50 +184,61 @@ class VimeoVideoElement extends MediaPlayedRangesMixin(globalThis.HTMLElement ??
...this.#config,
};

const onLoaded = async () => {
this.#readyState = 1; // HTMLMediaElement.HAVE_METADATA
this.dispatchEvent(new Event('loadedmetadata'));

if (this.api) {
this.#muted = await this.api.getMuted();
this.#volume = await this.api.getVolume();
this.dispatchEvent(new Event('volumechange'));

this.#duration = await this.api.getDuration();
this.dispatchEvent(new Event('durationchange'));
}

this.dispatchEvent(new Event('loadcomplete'));
this.loadComplete.resolve();
};

if (this.#isInit) {
this.api = oldApi;
await this.api.loadVideo({
...options,
url: this.src,
});
await onLoaded();
await this.#onLoaded();
await this.loadComplete;
return;
}
} else {
this.#isInit = true;

this.#isInit = true;
let iframe = this.shadowRoot?.querySelector('iframe');

let iframe = this.shadowRoot?.querySelector('iframe');
if (isFirstLoad && iframe) {
this.#config = JSON.parse(iframe.getAttribute('data-config') || '{}');
}

if (!this.shadowRoot) {
this.attachShadow({ mode: 'open' });
this.shadowRoot.innerHTML = getTemplateHTML(namedNodeMapToObject(this.attributes), this);
iframe = this.shadowRoot.querySelector('iframe');
}

if (isFirstLoad && iframe) {
this.#config = JSON.parse(iframe.getAttribute('data-config') || '{}');
this.api = new VimeoPlayerAPI(iframe, options);
this.#setupApiListeners();
await this.loadComplete;
}
}

disconnectedCallback() {
this.#loadRequested = null;
this.#hasLoaded = null;
this.#isInit = null;
super.disconnectedCallback?.()
}
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@cursor cursor bot Mar 24, 2026

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Stale loadComplete after disconnect causes premature resolution

High Severity

disconnectedCallback resets #hasLoaded to null but doesn't reset loadComplete. After reconnect, load() checks if (this.#hasLoaded) which is null (falsy), so it skips creating a new PublicPromise. The old already-resolved loadComplete is reused, causing await this.loadComplete at line 213 to resolve immediately — before the video actually loads. This also affects play(), pause(), and other methods that await this.loadComplete. Adding this.loadComplete = new PublicPromise() to disconnectedCallback would fix this.

Additional Locations (1)
Fix in Cursor Fix in Web


if (!this.shadowRoot) {
this.attachShadow({ mode: 'open' });
this.shadowRoot.innerHTML = getTemplateHTML(namedNodeMapToObject(this.attributes), this);
iframe = this.shadowRoot.querySelector('iframe');
#onLoaded = async () => {
this.#readyState = 1; // HTMLMediaElement.HAVE_METADATA
this.dispatchEvent(new Event('loadedmetadata'));

if (this.api) {
this.#muted = await this.api.getMuted();
this.#volume = await this.api.getVolume();
this.dispatchEvent(new Event('volumechange'));

this.#duration = await this.api.getDuration();
this.dispatchEvent(new Event('durationchange'));
}

this.api = new VimeoPlayerAPI(iframe);
this.dispatchEvent(new Event('loadcomplete'));
this.loadComplete.resolve();
};

#setupApiListeners() {
const textTracksVideo = document.createElement('video');
this.textTracks = textTracksVideo.textTracks;
this.api.getTextTracks().then((vimeoTracks) => {
Expand All @@ -247,7 +257,7 @@ class VimeoVideoElement extends MediaPlayedRangesMixin(globalThis.HTMLElement ??

const onceLoaded = () => {
this.api.off('loaded', onceLoaded);
onLoaded();
this.#onLoaded();
};
this.api.on('loaded', onceLoaded);

Expand Down Expand Up @@ -331,8 +341,6 @@ class VimeoVideoElement extends MediaPlayedRangesMixin(globalThis.HTMLElement ??
this.#videoHeight = videoHeight;
this.dispatchEvent(new Event('resize'));
});

await this.loadComplete;
}

async attributeChangedCallback(attrName, oldValue, newValue) {
Expand Down
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