refactor: flow -> ts

.eslintrc.json

@@ -9,7 +9,16 @@
   "env": { "node": true },
   "overrides": [
     {
-      "files": ["packages/*/src/**/*.js"],
+      "files": ["**/*.ts"],
+      "parser": "@typescript-eslint/parser",
+      "plugins": ["@typescript-eslint"],
+      "rules": {
+        "no-unused-vars": "off",
+        "@typescript-eslint/no-unused-vars": "error"
+      }
+    },
+    {
+      "files": ["packages/*/src/**/*.{js,ts}"],
       "rules": {
         "@babel/development/no-undefined-identifier": "error",
         "@babel/development/no-deprecated-clone": "error",

.github/workflows/ci.yml

@@ -50,8 +50,8 @@ jobs:
         run: yarn install
       - name: Lint
         run: yarn lint
-      - name: Flow
-        run: yarn flow
+      - name: TSCheck
+        run: yarn tscheck
       - name: Check compat-data
         run: yarn build-es-shims-data
         env:

.prettierrc

@@ -10,7 +10,7 @@
   "printWidth": 80,
   "overrides": [
     {
-      "files": ["**/packages/*/src/**/*.js", "**/packages/*/test/**/*.js"],
+      "files": ["**/packages/*/src/**/*.{js,ts}", "**/packages/*/test/**/*.{js,ts}"],
       "parser": "babylon",
       "options": {
         "trailingComma": "all"

CONTRIBUTING.md

@@ -41,7 +41,7 @@ $ yarn lint
 #### Type-check
 
 ```sh
-$ yarn flow
+$ yarn tscheck
 ```
 
 #### Test

Gulpfile.js

@@ -55,7 +55,7 @@ function build() {
   const base = path.join(__dirname, "packages");
 
   return gulp
-    .src("./packages/*/src/**/*.js", { base: base })
+    .src("./packages/*/src/**/*.{js,ts}", { base: base })
     .pipe(errorsLogger())
     .pipe(newer({ dest: base, map: swapSrcWithLib }))
     .pipe(compilationLogger())
@@ -85,7 +85,7 @@ async function buildRollup() {
       };
 
       const bundle = await rollup({
-        input: `${dir}/src/index.js`,
+        input: `${dir}/src/index.ts`,
         external,
         plugins: [
           rollupJson(),
@@ -127,7 +127,7 @@ gulp.task(
   "watch",
   gulp.series("build", function watch() {
     gulpWatch(
-      "./packages/*/src/**/*.js",
+      "./packages/*/src/**/*.{js,ts}",
       { debounceDelay: 200 },
       gulp.task("build")
     );

babel.config.json

@@ -2,9 +2,12 @@
   "sourceType": "unambiguous",
   "presets": [
     ["@babel/preset-env", { "loose": true }],
-    "@babel/preset-flow"
+    "@babel/preset-typescript"
+  ],
+  "plugins": [
+    "./scripts/babel-plugin-remove-create-require",
+    "./scripts/babel-plugin-compat-core-import"
   ],
-  "plugins": ["./scripts/babel-plugin-remove-create-require"],
   "targets": { "node": "current" },
   "env": {
     "production": {

package.json

@@ -8,12 +8,12 @@
     "build-es-shims-data": "./scripts/download-compat-table.sh && node ./scripts/build-es-shims-data",
     "clean": "rimraf packages/*/lib packages/*/esm",
     "clean-all": "yarn clean && rimraf packages/*/node_modules node_modules",
-    "flow": "flow check --strip-root",
-    "lint": "eslint packages '*.js' --format=codeframe",
+    "lint": "eslint packages '*.{js,ts}' --ext .js,.ts --format=codeframe",
     "publish": "yarn clean && NODE_ENV=production yarn build && yarn validate && lerna publish from-git",
     "test": "jest && yarn test:esm",
     "test:esm": "node test/esm/index.mjs",
-    "validate": "yarn lint && yarn flow && yarn test",
+    "tscheck": "yarn tsc",
+    "validate": "yarn lint && yarn tscheck && yarn test",
     "watch": "gulp watch"
   },
   "devDependencies": {
@@ -23,11 +23,14 @@
     "@babel/eslint-plugin-development": "^7.17.7",
     "@babel/plugin-transform-runtime": "^7.17.0",
     "@babel/preset-env": "^7.16.11",
-    "@babel/preset-flow": "^7.16.7",
+    "@babel/preset-typescript": "^7.16.7",
     "@babel/runtime": "^7.17.8",
     "@rollup/plugin-babel": "^5.3.0",
     "@rollup/plugin-json": "^4.1.0",
     "@rollup/plugin-node-resolve": "^11.2.0",
+    "@types/babel__traverse": "^7.14.2",
+    "@typescript-eslint/eslint-plugin": "^5.16.0",
+    "@typescript-eslint/parser": "^5.16.0",
     "babel-jest": "^24.8.0",
     "chalk": "^3.0.0",
     "electron-to-chromium": "^1.3.683",
@@ -37,7 +40,6 @@
     "eslint-plugin-import": "^2.17.2",
     "eslint-plugin-prettier": "^3.1.0",
     "fancy-log": "^1.3.3",
-    "flow-bin": "^0.107.0",
     "gulp": "^4.0.2",
     "gulp-babel": "^8.0.0",
     "gulp-newer": "^1.0.0",
@@ -51,7 +53,8 @@
     "prettier": "^2.6.1",
     "rimraf": "^2.6.3",
     "rollup": "^2.42.3",
-    "through2": "^2.0.0"
+    "through2": "^2.0.0",
+    "typescript": "^4.6.3"
   },
   "resolutions": {
     "@lerna/npm-publish": "patch:@lerna/npm-publish@npm:3.18.5#.yarn-patches/@lerna/npm-publish.patch",

packages/babel-helper-define-polyfill-provider/src/browser/dependencies.js → packages/babel-helper-define-polyfill-provider/src/browser/dependencies.ts

@@ -1,5 +1,3 @@
-// @flow
-
 export function resolve(
   dirname: string,
   moduleName: string,
@@ -12,13 +10,13 @@ export function resolve(
   );
 }
 
-// eslint-disable-next-line no-unused-vars
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
 export function has(basedir: string, name: string) {
   return true;
 }
 
-// eslint-disable-next-line no-unused-vars
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
 export function logMissing(missingDeps: Set<string>) {}
 
-// eslint-disable-next-line no-unused-vars
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
 export function laterLogMissing(missingDeps: Set<string>) {}

packages/babel-helper-define-polyfill-provider/src/debug-utils.js → packages/babel-helper-define-polyfill-provider/src/debug-utils.ts

@@ -1,5 +1,3 @@
-// @flow
-
 import { prettifyTargets } from "@babel/helper-compilation-targets";
 
 import type { Targets } from "./types";

packages/babel-helper-define-polyfill-provider/src/define-provider.js → packages/babel-helper-define-polyfill-provider/src/define-provider.ts

@@ -1,11 +1,9 @@
-// @flow
-
 import type { PolyfillProviderInternal, PolyfillProvider } from "./types";
 
 export function defineProvider<Options>(
   factory: PolyfillProvider<Options>,
 ): PolyfillProviderInternal<Options> {
   // This will allow us to do some things
 
-  return (factory: any);
+  return factory as any;
 }

packages/babel-helper-define-polyfill-provider/src/imports-cache.js → packages/babel-helper-define-polyfill-provider/src/imports-cache.ts

@@ -1,15 +1,12 @@
-// @flow
-
 import type { NodePath } from "@babel/traverse";
-import * as babel from "@babel/core";
-const { types: t } = babel.default || babel;
+import { types as t } from "@babel/core";
 
 type StrMap<K> = Map<string, K>;
 
 export default class ImportsCache {
-  _imports: WeakMap<NodePath, StrMap<string>>;
-  _anonymousImports: WeakMap<NodePath, Set<string>>;
-  _lastImports: WeakMap<NodePath, NodePath>;
+  _imports: WeakMap<NodePath<t.Program>, StrMap<string>>;
+  _anonymousImports: WeakMap<NodePath<t.Program>, Set<string>>;
+  _lastImports: WeakMap<NodePath<t.Program>, NodePath<t.Node>>;
   _resolver: (url: string) => string;
 
   constructor(resolver: (url: string) => string) {
@@ -20,13 +17,17 @@ export default class ImportsCache {
   }
 
   storeAnonymous(
-    programPath: NodePath,
+    programPath: NodePath<t.Program>,
     url: string,
     // eslint-disable-next-line no-undef
     getVal: (isScript: boolean, source: t.StringLiteral) => t.Node,
   ) {
     const key = this._normalizeKey(programPath, url);
-    const imports = this._ensure(this._anonymousImports, programPath, Set);
+    const imports = this._ensure<Set<string>>(
+      this._anonymousImports,
+      programPath,
+      Set,
+    );
 
     if (imports.has(key)) return;
 
@@ -39,7 +40,7 @@ export default class ImportsCache {
   }
 
   storeNamed(
-    programPath: NodePath,
+    programPath: NodePath<t.Program>,
     url: string,
     name: string,
     getVal: (
@@ -48,10 +49,14 @@ export default class ImportsCache {
       source: t.StringLiteral,
       // eslint-disable-next-line no-undef
       name: t.Identifier,
-    ) => { node: t.Node, name: string },
+    ) => { node: t.Node; name: string },
   ) {
     const key = this._normalizeKey(programPath, url, name);
-    const imports = this._ensure(this._imports, programPath, Map);
+    const imports = this._ensure<Map<string, any>>(
+      this._imports,
+      programPath,
+      Map,
+    );
 
     if (!imports.has(key)) {
       const { node, name: id } = getVal(
@@ -66,8 +71,9 @@ export default class ImportsCache {
     return t.identifier(imports.get(key));
   }
 
-  _injectImport(programPath: NodePath, node: t.Node) {
-    let lastImport = this._lastImports.get(programPath);
+  _injectImport(programPath: NodePath<t.Program>, node: t.Node) {
+    const lastImport = this._lastImports.get(programPath);
+    let newNodes: [NodePath];
     if (
       lastImport &&
       lastImport.node &&
@@ -76,12 +82,12 @@ export default class ImportsCache {
       lastImport.parent === programPath.node &&
       lastImport.container === programPath.node.body
     ) {
-      lastImport = lastImport.insertAfter(node);
+      newNodes = lastImport.insertAfter(node);
     } else {
-      lastImport = programPath.unshiftContainer("body", node);
+      newNodes = programPath.unshiftContainer("body", node);
     }
-    lastImport = lastImport[lastImport.length - 1];
-    this._lastImports.set(programPath, lastImport);
+    const newNode = newNodes[newNodes.length - 1];
+    this._lastImports.set(programPath, newNode);
 
     /*
     let lastImport;
@@ -106,10 +112,10 @@ export default class ImportsCache {
     });*/
   }
 
-  _ensure<C: Map<*, *> | Set<*>>(
-    map: WeakMap<NodePath, C>,
-    programPath: NodePath,
-    Collection: Class<C>,
+  _ensure<C extends Map<string, any> | Set<string>>(
+    map: WeakMap<NodePath<t.Program>, C>,
+    programPath: NodePath<t.Program>,
+    Collection: { new (...args: any): C },
   ): C {
     let collection = map.get(programPath);
     if (!collection) {
@@ -119,7 +125,11 @@ export default class ImportsCache {
     return collection;
   }
 
-  _normalizeKey(programPath: NodePath, url: string, name: string = ""): string {
+  _normalizeKey(
+    programPath: NodePath<t.Program>,
+    url: string,
+    name: string = "",
+  ): string {
     const { sourceType } = programPath.node;
 
     // If we rely on the imported binding (the "name" parameter), we also need to cache

packages/babel-helper-define-polyfill-provider/src/index.js → packages/babel-helper-define-polyfill-provider/src/index.ts

@@ -1,5 +1,3 @@
-// @flow
-
 import { declare } from "@babel/helper-plugin-utils";
 import type { NodePath } from "@babel/traverse";
 
@@ -41,13 +39,16 @@ function resolveOptions<Options>(
   options: PluginOptions,
   babelApi,
 ): {
-  method: MethodString,
-  methodName: "usageGlobal" | "entryGlobal" | "usagePure",
-  targets: Targets,
-  debug: boolean,
-  shouldInjectPolyfill: ?(name: string, shouldInject: boolean) => boolean,
-  providerOptions: ProviderOptions<Options>,
-  absoluteImports: string | boolean,
+  method: MethodString;
+  methodName: "usageGlobal" | "entryGlobal" | "usagePure";
+  targets: Targets;
+  debug: boolean | typeof presetEnvSilentDebugHeader;
+  shouldInjectPolyfill:
+    | ((name: string, shouldInject: boolean) => boolean)
+    | undefined
+    | null;
+  providerOptions: ProviderOptions<Options>;
+  absoluteImports: string | boolean;
 } {
   const {
     method,
@@ -141,7 +142,7 @@ See more options at https://github.com/babel/babel-polyfills/blob/main/docs/usag
     absoluteImports: absoluteImports ?? false,
     shouldInjectPolyfill,
     debug: !!debug,
-    providerOptions: ((providerOptions: Object): ProviderOptions<Options>),
+    providerOptions: providerOptions as any as ProviderOptions<Options>,
   };
 }
 
@@ -282,7 +283,6 @@ function instantiateProvider<Options>(
     provider,
     callProvider(payload: MetaDescriptor, path: NodePath) {
       const utils = getUtils(path);
-      // $FlowIgnore
       provider[methodName](payload, utils, path);
     },
   };
@@ -336,11 +336,9 @@ export default function definePolyfillProvider<Options>(
           missingDeps: new Set(),
         };
 
-        // $FlowIgnore - Flow doesn't support optional calls
         provider.pre?.apply(this, arguments);
       },
       post() {
-        // $FlowIgnore - Flow doesn't support optional calls
         provider.post?.apply(this, arguments);
 
         if (missingDependencies !== false) {

packages/babel-helper-define-polyfill-provider/src/meta-resolver.js → packages/babel-helper-define-polyfill-provider/src/meta-resolver.ts

@@ -1,5 +1,3 @@
-// @flow
-
 import type {
   MetaDescriptor,
   ResolverPolyfills,