feat: add TypeScript types (#67)

Note that these types explicitly do not include the default
export of the `Hook` function. That default export is just
there for backwards compat at this point.

CHANGELOG.md

@@ -1,10 +1,17 @@
 # require-in-the-middle changelog
 
+## Unreleased
+
+- Add [TypeScript types](./types/index.d.ts).
+  (/~https://github.com/elastic/require-in-the-middle/pull/67)
+
+
 ## v7.0.1
 
 - Fix hooking of 'http2' with Node.js versions [8.0, 8.8) where the 'http2'
-  built-in module was behind the `--expose-http2` flag. Release v7.0.0
-  introduced a bug with this case. The process would crash with:
+  built-in module was behind the `--expose-http2` flag.
+  (/~https://github.com/elastic/require-in-the-middle/pull/68)
+  Release v7.0.0 introduced a bug with this case where the process would crash with:
 
     ```
     AssertionError [ERR_ASSERTION]: unexpected that there is no Module entry for "http2" in require.cache

package.json

@@ -3,6 +3,7 @@
   "version": "7.0.1",
   "description": "Module to hook into the Node.js require function",
   "main": "index.js",
+  "types": "types/index.d.ts",
   "dependencies": {
     "debug": "^4.1.1",
     "module-details-from-path": "^1.0.3",
@@ -42,7 +43,9 @@
     "module",
     "load"
   ],
-  "files": [],
+  "files": [
+    "types"
+  ],
   "author": "Thomas Watson Steen <w@tson.dk> (https://twitter.com/wa7son)",
   "license": "MIT",
   "bugs": {

types/index.d.ts

@@ -0,0 +1,12 @@
+export interface HookOptions {
+  internals?: boolean;
+}
+
+export type OnRequireFn = <T>(exports: T, name: string, basedir?: string) => T;
+
+export class Hook {
+  constructor(modules: string[] | null, options: HookOptions | null, onrequire: OnRequireFn);
+  constructor(modules: string[] | null, onrequire: OnRequireFn);
+  constructor(onrequire: OnRequireFn);
+  unhook(): void;
+}