fix: add back generics to httpincoming

lib/http-incoming.js

@@ -10,18 +10,20 @@ const urlFromRequest = (request) => {
 };
 
 /**
+ * @template {Record<string, unknown>} [T=Record<string, unknown>]
  * @typedef {object} PodiumHttpIncoming
  * @property {string} name
  * @property {object} context
  * @property {object} view
  * @property {URL} url
  * @property {Array<import('./asset-css.js').CssAsset | string>} css
  * @property {Array<import('./asset-js.js').JavaScriptAsset | string>} js
- * @property {object} [params]
+ * @property {T} [params]
  * @property {boolean} [development]
  * @property {boolean} [proxy]
  */
 
+/** @template {Record<string, unknown>} [T=Record<string, unknown>] */
 export default class HttpIncoming {
     #development;
     #response;
@@ -48,15 +50,17 @@ export default class HttpIncoming {
     #js;
 
     /**
+     * @constructor
      * @param {object} [request={}] The incoming HTTP request
      * @param {object} [response={}] The HTTP response
-     * @param {object} [params={}] Parameters such as locale. Typically res.locals.
+     * @param {T} [params={}] Parameters such as locale. Typically res.locals.
      *
      * @example
      * ```js
      * const incoming = new HttpIncoming(req, res, res.locals);
      * ```
      */
+    // @ts-expect-error Not happy about the generics, but this is safe
     constructor(request = {}, response = {}, params = {}) {
         this.#development = false;
         this.#response = response;
@@ -143,6 +147,9 @@ export default class HttpIncoming {
         throw new Error('Cannot set read-only property.');
     }
 
+    /**
+     * @returns {T}
+     */
     get params() {
         return this.#params;
     }
@@ -201,7 +208,7 @@ export default class HttpIncoming {
     }
 
     /**
-     * @returns {PodiumHttpIncoming}
+     * @returns {PodiumHttpIncoming<T>}
      */
     toJSON() {
         return {

tests/http-incoming.test.js

@@ -125,6 +125,7 @@ tap.test('PodiumHttpIncoming.params - set value', (t) => {
     const incoming = new HttpIncoming(ADVANCED_REQ, SIMPLE_RES);
     t.throws(
         () => {
+            // @ts-ignore Testing bad input
             incoming.params = 'foo';
         },
         /Cannot set read-only property./,
@@ -311,3 +312,17 @@ tap.test(
         t.end();
     },
 );
+
+tap.test('generic typing works as expected', (t) => {
+    // really only here for tsc
+
+    /**
+     * @template {{ [key: string]: unknown }} T
+     * @param {( incoming: HttpIncoming<T>, fragment: string, ...args: unknown[]) => string} fn
+     * @returns {void}
+     */
+    // eslint-disable-next-line no-unused-vars
+    function view(fn) {}
+    t.ok(view);
+    t.end();
+});