feat(alias): Move to Typescript (#228)

packages/alias/package.json

@@ -11,6 +11,9 @@
   "homepage": "https://github.com/rollup/plugins/tree/master/packages/alias#readme",
   "bugs": "https://github.com/rollup/plugins/issues",
   "main": "dist/index.js",
+  "engines": {
+    "node": ">=8.0.0"
+  },
   "scripts": {
     "build": "rollup -c",
     "ci:coverage": "nyc pnpm run test && nyc report --reporter=text-lcov > coverage.lcov",
@@ -19,7 +22,7 @@
     "ci:test": "pnpm run test -- --verbose",
     "lint": "pnpm run lint:js && pnpm run lint:docs && pnpm run lint:package",
     "lint:docs": "prettier --single-quote --write README.md",
-    "lint:js": "eslint --fix --cache src test",
+    "lint:js": "eslint --fix --cache src test --ext .js,.ts",
     "lint:package": "prettier --write package.json --plugin=prettier-plugin-package",
     "prebuild": "del-cli dist",
     "prepare": "pnpm run build",
@@ -29,7 +32,7 @@
   },
   "files": [
     "dist",
-    "src",
+    "types",
     "README.md",
     "LICENSE"
   ],
@@ -47,16 +50,26 @@
   },
   "devDependencies": {
     "@rollup/plugin-node-resolve": "^7.0.0",
+    "@rollup/plugin-typescript": "^3.0.0",
     "del-cli": "^3.0.0",
     "rollup": "^1.27.14"
   },
   "ava": {
+    "compileEnhancements": false,
+    "extensions": [
+      "ts"
+    ],
+    "require": [
+      "ts-node/register"
+    ],
     "files": [
       "!**/fixtures/**",
+      "!**/output/**",
       "!**/helpers/**",
       "!**/recipes/**",
       "!**/types.ts"
     ]
   },
-  "module": "dist/index.es2015.js"
+  "module": "dist/index.es.js",
+  "types": "types/index.d.ts"
 }

packages/alias/rollup.config.js

@@ -1,10 +1,13 @@
+import typescript from '@rollup/plugin-typescript';
+
 import pkg from './package.json';
 
 export default {
-  input: 'src/index.js',
-  external: [...Object.keys(pkg.dependencies), 'path', 'fs', 'os'],
+  input: 'src/index.ts',
+  external: [...Object.keys(pkg.dependencies), 'os'],
   output: [
     { file: pkg.main, format: 'cjs' },
     { file: pkg.module, format: 'es' }
-  ]
+  ],
+  plugins: [typescript()]
 };

packages/alias/src/index.js → packages/alias/src/index.ts

@@ -1,13 +1,16 @@
 import { platform } from 'os';
 
+import { PartialResolvedId, Plugin } from 'rollup';
 import slash from 'slash';
 
+import { Alias, ResolverFunction, RollupAliasOptions } from '../types';
+
 const VOLUME = /^([A-Z]:)/i;
 const IS_WINDOWS = platform() === 'win32';
 
 // Helper functions
 const noop = () => null;
-const matches = (pattern, importee) => {
+function matches(pattern: string | RegExp, importee: string) {
   if (pattern instanceof RegExp) {
     return pattern.test(importee);
   }
@@ -20,16 +23,18 @@ const matches = (pattern, importee) => {
   const importeeStartsWithKey = importee.indexOf(pattern) === 0;
   const importeeHasSlashAfterKey = importee.substring(pattern.length)[0] === '/';
   return importeeStartsWithKey && importeeHasSlashAfterKey;
-};
+}
 
-const normalizeId = (id) => {
-  if ((IS_WINDOWS && typeof id === 'string') || VOLUME.test(id)) {
+function normalizeId(id: string): string;
+function normalizeId(id: string | undefined): string | undefined;
+function normalizeId(id: string | undefined) {
+  if (typeof id === 'string' && (IS_WINDOWS || VOLUME.test(id))) {
     return slash(id.replace(VOLUME, ''));
   }
   return id;
-};
+}
 
-const getEntries = ({ entries }) => {
+function getEntries({ entries }: RollupAliasOptions): Alias[] {
   if (!entries) {
     return [];
   }
@@ -38,17 +43,18 @@ const getEntries = ({ entries }) => {
     return entries;
   }
 
-  return Object.keys(entries).map((key) => {
-    return { find: key, replacement: entries[key] };
+  return Object.entries(entries).map(([key, value]) => {
+    return { find: key, replacement: value };
   });
-};
+}
 
-export default function alias(options = {}) {
+export default function alias(options: RollupAliasOptions = {}): Plugin {
   const entries = getEntries(options);
 
   // No aliases?
   if (entries.length === 0) {
     return {
+      name: 'alias',
       resolveId: noop
     };
   }
@@ -69,29 +75,29 @@ export default function alias(options = {}) {
         importeeId.replace(matchedEntry.find, matchedEntry.replacement)
       );
 
-      let customResolver = null;
+      let customResolver: ResolverFunction | null = null;
       if (typeof matchedEntry.customResolver === 'function') {
         ({ customResolver } = matchedEntry);
       } else if (
         typeof matchedEntry.customResolver === 'object' &&
-        typeof matchedEntry.customResolver.resolveId === 'function'
+        typeof matchedEntry.customResolver!.resolveId === 'function'
       ) {
-        customResolver = matchedEntry.customResolver.resolveId;
+        customResolver = matchedEntry.customResolver!.resolveId;
       } else if (typeof options.customResolver === 'function') {
         ({ customResolver } = options);
       } else if (
         typeof options.customResolver === 'object' &&
-        typeof options.customResolver.resolveId === 'function'
+        typeof options.customResolver!.resolveId === 'function'
       ) {
-        customResolver = options.customResolver.resolveId;
+        customResolver = options.customResolver!.resolveId;
       }
 
       if (customResolver) {
         return customResolver(updatedId, importerId);
       }
 
-      return this.resolve(updatedId, importer, { skipSelf: true }).then((resolved) => {
-        let finalResult = resolved;
+      return this.resolve(updatedId, importer!, { skipSelf: true }).then((resolved) => {
+        let finalResult: PartialResolvedId | null = resolved;
         if (!finalResult) {
           finalResult = { id: updatedId };
         }

packages/alias/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "lib": ["es6"],
+    "module": "esnext"
+  },
+  "include": [
+    "src/**/*",
+    "types/**/*"
+  ]
+}

packages/alias/types/index.d.ts

@@ -0,0 +1,38 @@
+import { Plugin, ResolveIdResult } from 'rollup';
+
+export interface Alias {
+    find: string | RegExp;
+    replacement: string;
+    customResolver?: ResolverFunction | ResolverObject | null;
+}
+
+export type ResolverFunction = (
+    source: string,
+    importer: string | undefined
+) => Promise<ResolveIdResult> | ResolveIdResult;
+
+export interface ResolverObject {
+    resolveId: ResolverFunction;
+}
+
+export interface RollupAliasOptions {
+    /**
+     * Instructs the plugin to use an alternative resolving algorithm,
+     * rather than the Rollup's resolver.
+     * @default null
+     */
+    customResolver?: ResolverFunction | ResolverObject | null;
+
+    /**
+     * Specifies an `Object`, or an `Array` of `Object`,
+     * which defines aliases used to replace values in `import` or `require` statements.
+     * With either format, the order of the entries is important,
+     * in that the first defined rules are applied first.
+     */
+    entries?: readonly Alias[] | { [find: string]: string };
+}
+
+/**
+ * 🍣 A Rollup plugin for defining aliases when bundling packages.
+ */
+export default function alias(options?: RollupAliasOptions): Plugin;