feat: migrate to TypeScript (#1134)

* feat: Allow to use TypeScript

* Add `prepack` script

* Add back `import` eslint plugin

* Shorten async function constructor syntax

Co-authored-by: Queen Vinyl Da.i'gyu-Kazotetsu <vinyldarkscratch@gmail.com>

* Use SWC

* Add swc dependency

---------

Co-authored-by: Queen Vinyl Da.i'gyu-Kazotetsu <vinyldarkscratch@gmail.com>

.eslintrc.json

@@ -1,15 +1,23 @@
 {
-  "extends": ["eslint:recommended", "plugin:import/errors", "prettier"],
-  "plugins": ["import"],
-  "parser": "@babel/eslint-parser",
-  "parserOptions": {
-    "ecmaVersion": 2021,
-    "sourceType": "module",
-    "requireConfigFile": false
-  },
   "env": {
     "es6": true,
     "browser": true,
     "node": true
+  },
+  "plugins": ["@typescript-eslint", "import"],
+  "extends": [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/recommended",
+    "plugin:import/errors",
+    "prettier"
+  ],
+  "parser": "@typescript-eslint/parser",
+  "parserOptions": {
+    "ecmaVersion": 2020,
+    "sourceType": "module"
+  },
+  "rules": {
+    "@typescript-eslint/no-explicit-any": "error",
+    "@typescript-eslint/no-unused-expressions": "error"
   }
 }

.prettierignore

@@ -5,3 +5,6 @@ docs
 node_modules
 # This can be removed after https://github.com/googleapis/release-please/issues/1802 is fixed
 CHANGELOG.md
+# TSC output:
+webpack.config.js
+lib/*.js

__tests__/console-utils.test.js

@@ -58,13 +58,11 @@ describe("console utils", () => {
 
   describe("formatArray", () => {
     test("Array formatting", () => {
-      expect(consoleUtils.formatArray(new Array(1, 2, 3, 4))).toBe(
-        "1, 2, 3, 4"
-      );
+      expect(consoleUtils.formatArray([1, 2, 3, 4])).toBe("1, 2, 3, 4");
     });
     test("Mixed array", () => {
       expect(
-        consoleUtils.formatArray(new Array(1, "a", { x: 2 }, null, undefined))
+        consoleUtils.formatArray([1, "a", { x: 2 }, null, undefined])
       ).toBe('1, "a", Object { x: 2 }, null, undefined');
     });
   });

editor/js/editable-wat.js

@@ -244,9 +244,8 @@ import {
       // Create an new async function from the code, and immediately execute it.
       // using an async function since WebAssembly.instantiate is async and
       // we need to await in order to capture errors
-      const AsyncFunction = Object.getPrototypeOf(
-        async function () {}
-      ).constructor;
+      // eslint-disable-next-line @typescript-eslint/no-empty-function
+      const AsyncFunction = async function () {}.constructor;
       await new AsyncFunction(exampleCode)();
     } catch (error) {
       console.error(error);

lib/config.js → lib/config.ts

@@ -8,8 +8,6 @@ function getConfig() {
   const configFile = path.join(__dirname, "../.bobconfigrc");
   const cosmiConfig = cosmiconfigSync("bobconfig", {
     cache: false,
-    format: "json",
-    sync: true,
   });
 
   const config = cosmiConfig.load(configFile).config;

lib/mdn-bob.js → lib/mdn-bob.ts

@@ -54,7 +54,7 @@ function doWebpack() {
         }
       }
 
-      resolve();
+      resolve(undefined);
     });
   });
 }