Add typescript information for core-js-builder

Signed-off-by: Ferdinand Thiessen <rpm@fthiessen.de>

packages/core-js-builder/README.md

@@ -32,3 +32,5 @@ const bundle = await builder({
   filename: PATH_TO_MY_COREJS_BUNDLE,
 });
 ```
+
+ℹ️ When using TypeScript, make sure to set `esModuleInterop` to `true`.

packages/core-js-builder/index.d.ts

@@ -0,0 +1,38 @@
+type Summary = {
+    size: boolean,
+    modules: boolean
+};
+
+type StringOrRegExp = string | RegExp;
+
+type MinEnvTarget = Record<string, string | readonly string[]> | { esmodules?: boolean };
+
+type Options = {
+    /** entry / module / namespace / an array of them, by default - all `core-js` modules */
+    modules?: StringOrRegExp | readonly StringOrRegExp[],
+    /** a blacklist of entries / modules / namespaces, by default - empty list */
+    exclude?: StringOrRegExp | readonly StringOrRegExp[],
+    /** optional browserslist or core-js-compat format query */
+    targets?: string | readonly string[] | MinEnvTarget,
+    /** output format, 'bundle' by default, can be 'cjs' or 'esm', and in this case
+     *  the result will not be bundled and will contain imports of required modules */
+    format?: 'bundle' | 'esm' | 'cjs',
+    /** optional target filename, if it's missed a file will not be created */
+    filename?: string,
+    /** shows summary for the bundle, disabled by default */
+    summary?: {
+        /** in the console, you could specify required parts or set `true` for enable all of them */
+        comment?: Summary,
+        /**  in the comment in the target file, similarly to `summary.console` */
+        console?: Summary,
+    }
+};
+
+declare function builder(options: Options): Promise<string>;
+
+export = builder;
+
+builder({targets: {
+    'foo': 'bar',
+    esmodules: true
+}})

packages/core-js-builder/package.json

@@ -19,6 +19,7 @@
   },
   "sideEffects": false,
   "main": "index.js",
+  "types": "index.d.ts",
   "dependencies": {
     "core-js": "3.27.1",
     "core-js-compat": "3.27.1",