The ExtendableEvent.waitUntil() method extends the lifetime of the event. When called in an EventHandler associated to the install event, it delays treating the installing worker as installed until the passed Promise resolves successfully. This is primarily used to ensure that a service worker is not considered installed until all of the core caches it depends on are populated.
The HTMLCanvasElement.toBlob() method creates a Blob object representing the image contained in the canvas; this file may be cached on the disk or stored in memory at the discretion of the user agent. If type is not specified, the image type is image/png. The created image is in a resolution of 96dpi.
The third argument is used with image/jpeg images to specify the quality of the output.
The HTMLFormElement.reportValidity() method returns true if the element's child controls satisfy their validation constraints. Whenfalse is returned, cancelable invalid events are fired for each invalid child and validation problems are reported to the user.
The Node.isEqualNode() method tests whether two nodes are equal. Two nodes are equal when they have the same type, defining characteristics (for elements, this would be their ID, number of children, and so forth), its attributes match, and so on. The specific set of data points that much match varies depending on the types of the nodes.