[types] improve types

index.d.ts

@@ -1,27 +1,12 @@
 declare namespace getSideChannel {
-	type Key = unknown;
-	type ListNode<T> = {
-		key: Key;
-		next: ListNode<T>;
-		value: T;
-	};
-	type RootNode<T> = {
-		key: object;
-		next: null | ListNode<T>;
-	};
-	function listGetNode<T>(list: RootNode<T>, key: ListNode<T>['key']): ListNode<T> | void;
-	function listGet<T>(objects: RootNode<T>, key: ListNode<T>['key']): T | void;
-	function listSet<T>(objects: RootNode<T>, key: ListNode<T>['key'], value: T): void;
-	function listHas<T>(objects: RootNode<T>, key: ListNode<T>['key']): boolean;
-
-	type Channel = {
-		assert: (key: Key) => void;
-		has: (key: Key) => boolean;
-		get: <T>(key: Key) => T;
-		set: <T>(key: Key, value: T) => void;
+	type Channel<V, K> = {
+		assert: (key: K) => void;
+		has: (key: K) => boolean;
+		get: (key: K) => V | undefined;
+		set: (key: K, value: V) => void;
 	}
 }
 
-declare function getSideChannel(): getSideChannel.Channel;
+declare function getSideChannel<V, K>(): getSideChannel.Channel<V, K>;
 
 export = getSideChannel;

index.js

@@ -8,19 +8,27 @@ var $TypeError = require('es-errors/type');
 var $WeakMap = GetIntrinsic('%WeakMap%', true);
 var $Map = GetIntrinsic('%Map%', true);
 
+/** @template T @typedef {<T extends (this: any, ...args: any[]) => any>(this: ThisParameterType<T>, ...args: Parameters<T>) => ReturnType<T>} CallBind */
+
+/** @type {CallBind<<K extends object, V>(this: WeakMap<K, V>, key: K) => V>} */
 var $weakMapGet = callBound('WeakMap.prototype.get', true);
+/** @type {CallBind<typeof WeakMap.prototype.set>} */
 var $weakMapSet = callBound('WeakMap.prototype.set', true);
+/** @type {CallBind<typeof WeakMap.prototype.has>} */
 var $weakMapHas = callBound('WeakMap.prototype.has', true);
+/** @type {CallBind<typeof Map.prototype.get>} */
 var $mapGet = callBound('Map.prototype.get', true);
+/** @type {CallBind<typeof Map.prototype.set>} */
 var $mapSet = callBound('Map.prototype.set', true);
+/** @type {CallBind<typeof Map.prototype.has>} */
 var $mapHas = callBound('Map.prototype.has', true);
 
 /*
 * This function traverses the list returning the node corresponding to the given key.
 *
 * That node is also moved to the head of the list, so that if it's accessed again we don't need to traverse the whole list. By doing so, all the recently used nodes can be accessed relatively quickly.
 */
-/** @type {import('.').listGetNode} */
+/** @type {import('./list.d.ts').listGetNode} */
 var listGetNode = function (list, key) { // eslint-disable-line consistent-return
 	/** @type {typeof list | NonNullable<(typeof list)['next']>} */
 	var prev = list;
@@ -37,37 +45,41 @@ var listGetNode = function (list, key) { // eslint-disable-line consistent-retur
 	}
 };
 
-/** @type {import('.').listGet} */
+/** @type {import('./list.d.ts').listGet} */
 var listGet = function (objects, key) {
 	var node = listGetNode(objects, key);
 	return node && node.value;
 };
-/** @type {import('.').listSet} */
+/** @type {import('./list.d.ts').listSet} */
 var listSet = function (objects, key, value) {
 	var node = listGetNode(objects, key);
 	if (node) {
 		node.value = value;
 	} else {
 		// Prepend the new node to the beginning of the list
-		objects.next = /** @type {import('.').ListNode<typeof value>} */ ({ // eslint-disable-line no-param-reassign, no-extra-parens
+		objects.next = /** @type {import('./list.d.ts').ListNode<typeof value, typeof key>} */ ({ // eslint-disable-line no-param-reassign, no-extra-parens
 			key: key,
 			next: objects.next,
 			value: value
 		});
 	}
 };
-/** @type {import('.').listHas} */
+/** @type {import('./list.d.ts').listHas} */
 var listHas = function (objects, key) {
 	return !!listGetNode(objects, key);
 };
 
 /** @type {import('.')} */
 module.exports = function getSideChannel() {
-	/** @type {WeakMap<object, unknown>} */ var $wm;
-	/** @type {Map<object, unknown>} */ var $m;
-	/** @type {import('.').RootNode<unknown>} */ var $o;
+	/** @typedef {ReturnType<typeof getSideChannel>} Channel */
+	/** @typedef {Parameters<Channel['get']>[0]} K */
+	/** @typedef {Parameters<Channel['set']>[1]} V */
+
+	/** @type {WeakMap<K & object, V> | undefined} */ var $wm;
+	/** @type {Map<K, V> | undefined} */ var $m;
+	/** @type {import('./list.d.ts').RootNode<V, K> | undefined} */ var $o;
 
-	/** @type {import('.').Channel} */
+	/** @type {Channel} */
 	var channel = {
 		assert: function (key) {
 			if (!channel.has(key)) {
@@ -125,5 +137,6 @@ module.exports = function getSideChannel() {
 			}
 		}
 	};
+	// @ts-expect-error TODO: figure out why this is erroring
 	return channel;
 };

list.d.ts

@@ -0,0 +1,14 @@
+type ListNode<T, K> = {
+	key: K;
+	next: ListNode<T, K>;
+	value: T;
+};
+type RootNode<T, K> = {
+	key: object;
+	next: null | ListNode<T, K>;
+};
+
+export function listGetNode<T, K>(list: RootNode<T, K>, key: ListNode<T, K>['key']): ListNode<T, K> | void;
+export function listGet<T, K>(objects: RootNode<T, K>, key: ListNode<T, K>['key']): T | void;
+export function listSet<T, K>(objects: RootNode<T, K>, key: ListNode<T, K>['key'], value: T): void;
+export function listHas<T, K>(objects: RootNode<T, K>, key: ListNode<T, K>['key']): boolean;

package.json

@@ -42,6 +42,12 @@
 		"url": "https://github.com/ljharb/side-channel/issues"
 	},
 	"homepage": "https://github.com/ljharb/side-channel#readme",
+	"dependencies": {
+		"call-bind": "^1.0.8",
+		"es-errors": "^1.3.0",
+		"get-intrinsic": "^1.2.5",
+		"object-inspect": "^1.13.3"
+	},
 	"devDependencies": {
 		"@ljharb/eslint-config": "^21.1.1",
 		"@ljharb/tsconfig": "^0.2.2",
@@ -60,12 +66,6 @@
 		"tape": "^5.9.0",
 		"typescript": "next"
 	},
-	"dependencies": {
-		"call-bind": "^1.0.8",
-		"es-errors": "^1.3.0",
-		"get-intrinsic": "^1.2.5",
-		"object-inspect": "^1.13.3"
-	},
 	"auto-changelog": {
 		"output": "CHANGELOG.md",
 		"template": "keepachangelog",

tsconfig.json

@@ -1,7 +1,7 @@
 {
 	"extends": "@ljharb/tsconfig",
 	"compilerOptions": {
-		"target": "es2021",																	/* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
+		"target": "es2021",
 	},
 	"exclude": [
 		"coverage",