feat!(parse-function): simpler API, rewrite to TypeScript

BREAKING CHANGE: exposes named function `parseFunction(Input, Options): Result`

The `options.parse` can be any parser `.parse` method, tested against Babel, ESPree & Acorn

```ts
type Input = string | (...args: any) => any;

interface Options {
  parse?(input: string, options?: ParserOptions): import('@babel/types').File;
  parserOptions?: ParserOptions;
  plugins?: Plugins;
}

type Plugin = (node: any, result: Result) => Result | undefined;
type Plugins = Plugin | Array<Plugin>;

interface Result {
  name: string | null;
  body: string;
  args: Array<string>;
  params: string;
  defaults: { [key: string]: string | undefined };
  value: string;
  isValid: boolean;
  isArrow: boolean;
  isAsync: boolean;
  isNamed: boolean;
  isAnonymous: boolean;
  isGenerator: boolean;
  isExpression: boolean;
}
```

Signed-off-by: Charlike Mike Reagent <[email protected]>

Author: tunnckoCore

@types/undeclared.d.ts

@@ -0,0 +1,6 @@
+declare module 'espree';
+declare module 'acorn-loose';
+declare module 'for-in';
+declare module 'define-property' {
+  export default function(obj: any, name: string, value: any): void;
+}

package.json

@@ -34,25 +34,29 @@
     "@babel/plugin-transform-runtime": "^7.6.2",
     "@commitlint/cli": "^8.2.0",
     "@commitlint/config-conventional": "^8.2.0",
+    "@types/jest": "^24.0.19",
+    "@types/node": "^12.11.1",
+    "@types/react": "^16.9.9",
+    "@types/react-dom": "^16.9.2",
     "@wessberg/rollup-plugin-ts": "^1.1.73",
+    "acorn-loose": "^7.0.0",
     "builtin-modules": "^3.1.0",
     "enquirer": "^2.3.2",
-    "eslint": "^6.4.0",
+    "eslint": "^6.5.1",
     "esm": "^3.2.25",
     "husky": "^3.0.9",
     "jest": "^24.9.0",
-    "lerna": "^3.16.4",
+    "lerna": "^3.18.1",
     "prettier": "^1.18.2",
     "prettier-plugin-pkg": "^0.4.4",
-    "prettier-plugin-sh": "^0.2.0",
-    "react": "^16.10.1",
-    "rollup": "^1.23.1",
+    "prettier-plugin-sh": "^0.2.1",
+    "react": "^16.10.2",
+    "rollup": "^1.25.0",
     "rollup-plugin-commonjs": "^10.1.0",
     "rollup-plugin-json": "^4.0.0",
     "rollup-plugin-node-resolve": "^5.2.0",
     "rollup-plugin-terser": "^5.1.2",
-    "semver": "^6.3.0",
-    "typescript": "^3.7.0-beta",
+    "typescript": "^3.6.4",
     "verb": "verbose/verb#dev",
     "verb-generate-readme": "^0.8.0"
   },
@@ -69,11 +73,11 @@
   },
   "meta": {
     "build": [
-      "koa-better-body"
+      "koa-better-body",
+      "parse-function"
     ],
     "bundle": [
-      "@tunnckocore/execa",
-      "parse-function"
+      "@tunnckocore/execa"
     ]
   },
   "renovate": {

packages/parse-function/package.json

@@ -13,8 +13,8 @@
   "engines": {
     "node": ">=8.11"
   },
-  "main": "dist/cjs/index.js",
-  "module": "dist/esm/index.js",
+  "main": "dist/main/index.js",
+  "module": "dist/module/index.js",
   "types": "dist/types/index.d.ts",
   "files": [
     "dist"
@@ -48,7 +48,9 @@
   ],
   "scripts": {},
   "dependencies": {
-    "@babel/parser": "^7.6.4"
+    "@types/babel__core": "^7.1.3",
+    "@babel/parser": "^7.6.4",
+    "@babel/types": "^7.6.3"
   },
   "devDependencies": {
     "acorn": "^7.1.0",

packages/parse-function/src/index.js

@@ -0,0 +1,41 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import arrayify from 'arrify';
+import { parse as babelParse } from '@babel/parser';
+
+import { setDefaults, getNode } from './utils';
+import { Input, Options, Plugin, Result } from './types';
+
+import basePlugin from './plugins/initial';
+
+// eslint-disable-next-line import/prefer-default-export
+export function parseFunction(code: Input, options?: Options) {
+  const opts: Options = { parse: babelParse, ...options };
+  const result: Result = setDefaults(code);
+
+  if (!result.isValid) {
+    return result;
+  }
+
+  const isFunction = result.value.startsWith('function');
+  const isAsyncFn = result.value.startsWith('async function');
+  const isAsync = result.value.startsWith('async');
+  const isArrow = result.value.includes('=>');
+  const isAsyncArrow = isAsync && isArrow;
+
+  const isMethod = /^\*?.+\([\s\S\w\W]*\)\s*\{/i.test(result.value);
+
+  if (!(isFunction || isAsyncFn || isAsyncArrow) && isMethod) {
+    result.value = `{ ${result.value} }`;
+  }
+
+  const node = getNode(result, opts);
+  const plugins = arrayify(opts.plugins);
+
+  return [basePlugin, ...plugins]
+    .filter(Boolean)
+    .reduce((res: any, fn: Plugin) => {
+      const pluginResult = fn(node, { ...res }) || res;
+
+      return pluginResult;
+    }, result);
+}