Merge pull request #18 from DavidANeil/davidneil-promise-catch

Type error in Promise catch methods as unknown

.changeset/tender-socks-rush.md

@@ -0,0 +1,21 @@
+---
+"@total-typescript/ts-reset": minor
+---
+
+Added a rule, `/promise-catch`, to change the `catch` method to take `unknown` instead of `any` as an argument.
+
+```ts
+const promise = Promise.reject("error");
+
+// BEFORE
+
+promise.catch((error) => {
+  console.error(error); // error is any!
+});
+
+// AFTER
+
+promise.catch((error) => {
+  console.error(error); // error is unknown!
+});
+```

package.json

@@ -62,6 +62,11 @@
       "import": "./dist/set-has.mjs",
       "default": "./dist/set-has.js"
     },
+    "./promise-catch": {
+      "types": "./dist/promise-catch.d.ts",
+      "import": "./dist/promise-catch.mjs",
+      "default": "./dist/promise-catch.js"
+    },
     "./map-constructor": {
       "types": "./dist/map-constructor.d.ts",
       "import": "./dist/map-constructor.mjs",

src/entrypoints/promise-catch.d.ts

@@ -0,0 +1,30 @@
+interface Promise<T> {
+  /**
+   * Attaches callbacks for the resolution and/or rejection of the Promise.
+   * @param onfulfilled The callback to execute when the Promise is resolved.
+   * @param onrejected The callback to execute when the Promise is rejected.
+   * @returns A Promise for the completion of which ever callback is executed.
+   */
+  then<TResult1 = T, TResult2 = never>(
+    onfulfilled?:
+      | ((value: T) => TResult1 | PromiseLike<TResult1>)
+      | undefined
+      | null,
+    onrejected?:
+      | ((reason: unknown) => TResult2 | PromiseLike<TResult2>)
+      | undefined
+      | null,
+  ): Promise<TResult1 | TResult2>;
+
+  /**
+   * Attaches a callback for only the rejection of the Promise.
+   * @param onrejected The callback to execute when the Promise is rejected.
+   * @returns A Promise for the completion of the callback.
+   */
+  catch<TResult = never>(
+    onrejected?:
+      | ((reason: unknown) => TResult | PromiseLike<TResult>)
+      | undefined
+      | null,
+  ): Promise<T | TResult>;
+}

src/entrypoints/recommended.d.ts

@@ -7,3 +7,4 @@
 /// <reference path="map-constructor.d.ts" />
 /// <reference path="map-has.d.ts" />
 /// <reference path="array-index-of.d.ts" />
+/// <reference path="promise-catch.d.ts" />

src/tests/promise-catch.ts

@@ -0,0 +1,14 @@
+import { doNotExecute, Equal, Expect } from "./utils";
+
+doNotExecute(async () => {
+  Promise.reject("string instead of Error").catch((err) => {
+    type test = Expect<Equal<unknown, typeof err>>;
+  });
+
+  Promise.reject("string instead of Error").then(
+    () => {},
+    (err) => {
+      type test = Expect<Equal<unknown, typeof err>>;
+    },
+  );
+});