So far as I can tell, although jsx.d.ts includes a definition for composition events such as onCompositionEnd, they are not implemented.

Furthermore, while isComposing is available through InputEvent, it is not normalized between browsers so, for example, in Firefox there will be an input event where it is true but there is not in Chrome. Without composition events it is not possible to work around this and, for example, only update search results once the current composition has been committed.

Test case:

https://codesandbox.io/s/bold-currying-vqfq8