keyof T should never print as a union of strings

Aucun fichier du dépôt ni chemin de test n’est mentionné. Reproduisez le problème avec l’extrait fourni et TypeScript 3.6.2, puis suivez la génération des déclarations et l’impression des types afin d’identifier l’endroit où la contrainte générique est développée. C’est terminé lorsque la déclaration générée conserve K comme étendant keyof HTMLElementEventMap au lieu d’imprimer l’union des noms d’événements.

TypeScript Version: 3.6.2

Search Terms: extends keyof generic

Code

export const bindEvent = <Node extends HTMLElement | HTMLDocument,
	K extends keyof HTMLElementEventMap>(
	node: Node,
	type: K,
	callback: (event: HTMLElementEventMap[K]) => unknown,
) => {
	node.addEventListener(type, callback as EventListener);

	return () => {
		node.removeEventListener(type, callback as EventListener);
	};
};

tsc

Expected behavior:
The generic K to still be extends keyof, instead of spreading the type out.

Actual behavior:
types generated:

export declare const bindEvent: <Node_1 extends HTMLElement | HTMLDocument, K extends "fullscreenchange" | "fullscreenerror" | "abort" | "animationcancel" | "animationend" | "animationiteration" | "animationstart" | "auxclick" | "blur" | "cancel" | "canplay" | "canplaythrough" | "change" | "click" | "close" | "contextmenu" | "cuechange" | "dblclick" | "drag" | "dragend" | "dragenter" | "dragexit" | "dragleave" | "dragover" | "dragstart" | "drop" | "durationchange" | "emptied" | "ended" | "error" | "focus" | "focusin" | "focusout" | "gotpointercapture" | "input" | "invalid" | "keydown" | "keypress" | "keyup" | "load" | "loadeddata" | "loadedmetadata" | "loadend" | "loadstart" | "lostpointercapture" | "mousedown" | "mouseenter" | "mouseleave" | "mousemove" | "mouseout" | "mouseover" | "mouseup" | "pause" | "play" | "playing" | "pointercancel" | "pointerdown" | "pointerenter" | "pointerleave" | "pointermove" | "pointerout" | "pointerover" | "pointerup" | "progress" | "ratechange" | "reset" | "resize" | "scroll" | "securitypolicyviolation" | "seeked" | "seeking" | "select" | "selectionchange" | "selectstart" | "stalled" | "submit" | "suspend" | "timeupdate" | "toggle" | "touchcancel" | "touchend" | "touchmove" | "touchstart" | "transitioncancel" | "transitionend" | "transitionrun" | "transitionstart" | "volumechange" | "waiting" | "wheel" | "copy" | "cut" | "paste">(node: Node_1, type: K, callback: (event: HTMLElementEventMap[K]) => unknown) => () => void;