Improve preset-env typings (#14606)

* refactor: move shipped-proposals to ts

* preset-env

* address review comments

packages/babel-core/src/config/cache-contexts.ts

@@ -16,7 +16,7 @@ export type FullPlugin = {
 // process 'ignore'/'only' and other filename-based logic.
 export type SimpleConfig = {
   envName: string;
-  caller: CallerMetadata | void;
+  caller: CallerMetadata | undefined;
 };
 export type SimplePreset = {
   targets: Targets;

packages/babel-core/src/config/config-chain.ts

@@ -55,7 +55,7 @@ export type ConfigContext = {
   cwd: string;
   root: string;
   envName: string;
-  caller: CallerMetadata | void;
+  caller: CallerMetadata | undefined;
   showConfig: boolean;
 };
 

packages/babel-core/src/config/files/configuration.ts

@@ -57,7 +57,7 @@ export function findConfigUpwards(rootDir: string): string | null {
 export function* findRelativeConfig(
   packageData: FilePackageData,
   envName: string,
-  caller: CallerMetadata | void,
+  caller: CallerMetadata | undefined,
 ): Handler<RelativeConfig> {
   let config = null;
   let ignore = null;
@@ -93,7 +93,7 @@ export function* findRelativeConfig(
 export function findRootConfig(
   dirname: string,
   envName: string,
-  caller: CallerMetadata | void,
+  caller: CallerMetadata | undefined,
 ): Handler<ConfigFile | null> {
   return loadOneConfig(ROOT_CONFIG_FILENAMES, dirname, envName, caller);
 }
@@ -102,7 +102,7 @@ function* loadOneConfig(
   names: string[],
   dirname: string,
   envName: string,
-  caller: CallerMetadata | void,
+  caller: CallerMetadata | undefined,
   previousConfig: ConfigFile | null = null,
 ): Handler<ConfigFile | null> {
   const configs = yield* gensync.all(
@@ -133,7 +133,7 @@ export function* loadConfig(
   name: string,
   dirname: string,
   envName: string,
-  caller: CallerMetadata | void,
+  caller: CallerMetadata | undefined,
 ): Handler<ConfigFile> {
   const filepath = require.resolve(name, { paths: [dirname] });
 
@@ -163,7 +163,7 @@ const readConfigJS = makeStrongCache(function* readConfigJS(
   filepath: string,
   cache: CacheConfigurator<{
     envName: string;
-    caller: CallerMetadata | void;
+    caller: CallerMetadata | undefined;
   }>,
 ): Handler<ConfigFile | null> {
   if (!nodeFs.existsSync(filepath)) {

packages/babel-core/src/config/files/index-browser.ts

@@ -35,7 +35,7 @@ export function* findRelativeConfig(
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   envName: string,
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
-  caller: CallerMetadata | void,
+  caller: CallerMetadata | undefined,
 ): Handler<RelativeConfig> {
   return { config: null, ignore: null };
 }
@@ -47,7 +47,7 @@ export function* findRootConfig(
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   envName: string,
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
-  caller: CallerMetadata | void,
+  caller: CallerMetadata | undefined,
 ): Handler<ConfigFile | null> {
   return null;
 }
@@ -59,7 +59,7 @@ export function* loadConfig(
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   envName: string,
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
-  caller: CallerMetadata | void,
+  caller: CallerMetadata | undefined,
 ): Handler<ConfigFile> {
   throw new Error(`Cannot load ${name} relative to ${dirname} in a browser`);
 }

packages/babel-core/src/config/helpers/config-api.ts

@@ -21,7 +21,7 @@ type EnvFunction = {
 };
 
 type CallerFactory = (
-  extractor: (callerMetadata: CallerMetadata | void) => unknown,
+  extractor: (callerMetadata: CallerMetadata | undefined) => unknown,
 ) => SimpleType;
 type TargetsFunction = () => Targets;
 type AssumptionFunction = (name: AssumptionName) => boolean | void;

packages/babel-core/src/config/validation/option-assertions.ts

@@ -135,7 +135,7 @@ export function assertSourceType(
 export function assertCallerMetadata(
   loc: OptionPath,
   value: unknown,
-): CallerMetadata | void {
+): CallerMetadata | undefined {
   const obj = assertObject(loc, value);
   if (obj) {
     if (typeof obj.name !== "string") {

packages/babel-plugin-transform-parameters/src/rest.ts

@@ -1,4 +1,39 @@
 import { template, types as t } from "@babel/core";
+import type { NodePath, Visitor } from "@babel/traverse";
+
+type Candidate = {
+  cause: "indexGetter" | "lengthGetter" | "argSpread";
+  path: NodePath<t.Identifier | t.JSXIdentifier>;
+};
+
+type State = {
+  references: [];
+  offset: number;
+
+  argumentsNode: t.Identifier;
+  outerBinding: t.Identifier;
+
+  // candidate member expressions we could optimise if there are no other references
+  candidates: Candidate[];
+
+  // local rest binding name
+  name: string;
+
+  /*
+  It may be possible to optimize the output code in certain ways, such as
+  not generating code to initialize an array (perhaps substituting direct
+  references to arguments[i] or arguments.length for reads of the
+  corresponding rest parameter property) or positioning the initialization
+  code so that it may not have to execute depending on runtime conditions.
+
+  This property tracks eligibility for optimization. "deopted" means give up
+  and don't perform optimization. For example, when any of rest's elements /
+  properties is assigned to at the top level, or referenced at all in a
+  nested function.
+  */
+  deopted: boolean;
+  noOptimise: boolean;
+};
 
 const buildRest = template(`
   for (var LEN = ARGUMENTS.length,
@@ -22,7 +57,10 @@ const restLength = template(`
   ARGUMENTS.length <= OFFSET ? 0 : ARGUMENTS.length - OFFSET
 `);
 
-function referencesRest(path, state) {
+function referencesRest(
+  path: NodePath<t.Identifier | t.JSXIdentifier>,
+  state: State,
+) {
   if (path.node.name === state.name) {
     // Check rest parameter is not shadowed by a binding in another scope.
     return path.scope.bindingIdentifierEquals(state.name, state.outerBinding);
@@ -31,15 +69,15 @@ function referencesRest(path, state) {
   return false;
 }
 
-const memberExpressionOptimisationVisitor = {
+const memberExpressionOptimisationVisitor: Visitor<State> = {
   Scope(path, state) {
     // check if this scope has a local binding that will shadow the rest parameter
     if (!path.scope.bindingIdentifierEquals(state.name, state.outerBinding)) {
       path.skip();
     }
   },
 
-  Flow(path) {
+  Flow(path: NodePath<t.Flow>) {
     // Do not skip TypeCastExpressions as the contain valid non flow code
     if (path.isTypeCastExpression()) return;
     // don't touch reference in type annotations

packages/babel-plugin-transform-runtime/src/index.ts

@@ -18,7 +18,7 @@ const pluginRegenerator = (_pluginRegenerator.default ||
 
 const pluginsCompat = "#__secret_key__@babel/runtime__compatibility";
 
-function supportsStaticESM(caller: CallerMetadata | void) {
+function supportsStaticESM(caller: CallerMetadata | undefined) {
   // @ts-ignore TS does not narrow down optional chaining
   return !!caller?.supportsStaticESM;
 }

packages/babel-preset-env/data/shipped-proposals.js

@@ -1,36 +1,2 @@
-/* eslint sort-keys: "error" */
-// These mappings represent the transform plugins that have been
-// shipped by browsers, and are enabled by the `shippedProposals` option.
-
-const proposalPlugins = new Set();
-
-// proposal syntax plugins enabled by the `shippedProposals` option.
-// Unlike proposalPlugins above, they are independent of compiler targets.
-const proposalSyntaxPlugins = [
-  "syntax-import-assertions"
-]
-
-// use intermediary object to enforce alphabetical key order
-const pluginSyntaxObject = {
-  "proposal-async-generator-functions": "syntax-async-generators",
-  "proposal-class-properties": "syntax-class-properties",
-  "proposal-class-static-block": "syntax-class-static-block",
-  "proposal-json-strings": "syntax-json-strings",
-  "proposal-nullish-coalescing-operator": "syntax-nullish-coalescing-operator",
-  "proposal-numeric-separator": "syntax-numeric-separator",
-  "proposal-object-rest-spread": "syntax-object-rest-spread",
-  "proposal-optional-catch-binding": "syntax-optional-catch-binding",
-  "proposal-optional-chaining": "syntax-optional-chaining",
-  // note: we don't have syntax-private-methods
-  "proposal-private-methods": "syntax-class-properties",
-  "proposal-private-property-in-object": "syntax-private-property-in-object",
-  "proposal-unicode-property-regex": null,
-};
-
-const pluginSyntaxEntries = Object.keys(pluginSyntaxObject).map(function (key) {
-  return [key, pluginSyntaxObject[key]];
-});
-
-const pluginSyntaxMap = new Map(pluginSyntaxEntries);
-
+const { pluginSyntaxMap, proposalPlugins, proposalSyntaxPlugins } = require("../lib/shipped-proposals");
 module.exports = { pluginSyntaxMap, proposalPlugins, proposalSyntaxPlugins };

packages/babel-preset-env/src/debug.ts

@@ -24,6 +24,7 @@ export const logPlugin = (
     if (!first) formattedTargets += `,`;
     first = false;
     formattedTargets += ` ${target}`;
+    // @ts-ignore
     if (support[target]) formattedTargets += ` < ${support[target]}`;
   }
   formattedTargets += ` }`;

packages/babel-preset-env/src/filter-items.ts

@@ -6,7 +6,7 @@ const has = Function.call.bind(Object.hasOwnProperty);
 
 export function addProposalSyntaxPlugins(
   items: Set<string>,
-  proposalSyntaxPlugins: string[],
+  proposalSyntaxPlugins: readonly string[],
 ) {
   proposalSyntaxPlugins.forEach(plugin => {
     items.add(plugin);
@@ -25,7 +25,14 @@ export function removeUnsupportedItems(
   babelVersion: string,
 ) {
   items.forEach(item => {
-    if (has(minVersions, item) && lt(babelVersion, minVersions[item])) {
+    if (
+      has(minVersions, item) &&
+      lt(
+        babelVersion,
+        // @ts-ignore we have checked minVersions[item] in has call
+        minVersions[item],
+      )
+    ) {
       items.delete(item);
     }
   });

packages/babel-preset-env/src/index.ts

@@ -13,7 +13,7 @@ import {
   pluginSyntaxMap,
   proposalPlugins,
   proposalSyntaxPlugins,
-} from "../data/shipped-proposals";
+} from "./shipped-proposals";
 import {
   plugins as pluginsList,
   pluginsBugfixes as pluginsBugfixesList,
@@ -23,6 +23,8 @@ import overlappingPlugins from "@babel/compat-data/overlapping-plugins";
 import removeRegeneratorEntryPlugin from "./polyfills/regenerator";
 import legacyBabelPolyfillPlugin from "./polyfills/babel-polyfill";
 
+import type { CallerMetadata } from "@babel/core";
+
 import _pluginCoreJS2 from "babel-plugin-polyfill-corejs2";
 import _pluginCoreJS3 from "babel-plugin-polyfill-corejs3";
 import _pluginRegenerator from "babel-plugin-polyfill-regenerator";
@@ -56,6 +58,7 @@ function filterStageFromList(
 ) {
   return Object.keys(list).reduce((result, item) => {
     if (!stageList.has(item)) {
+      // @ts-ignore
       result[item] = list[item];
     }
 
@@ -88,7 +91,9 @@ function getPluginList(proposals: boolean, bugfixes: boolean) {
 }
 
 const getPlugin = (pluginName: string) => {
-  const plugin = availablePlugins[pluginName]();
+  const plugin =
+    // @ts-ignore plugin name is constructed from available plugin list
+    availablePlugins[pluginName]();
 
   if (!plugin) {
     throw new Error(
@@ -244,10 +249,10 @@ export const getPolyfillPlugins = ({
 };
 
 function getLocalTargets(
-  optionsTargets,
-  ignoreBrowserslistConfig,
-  configPath,
-  browserslistEnv,
+  optionsTargets: Options["targets"],
+  ignoreBrowserslistConfig: boolean,
+  configPath: string,
+  browserslistEnv: string,
 ) {
   if (optionsTargets?.esmodules && optionsTargets.browsers) {
     console.warn(`
@@ -263,19 +268,23 @@ function getLocalTargets(
   });
 }
 
-function supportsStaticESM(caller) {
+function supportsStaticESM(caller: CallerMetadata | undefined) {
+  // @ts-expect-error supportsStaticESM is not defined in CallerMetadata
   return !!caller?.supportsStaticESM;
 }
 
-function supportsDynamicImport(caller) {
+function supportsDynamicImport(caller: CallerMetadata | undefined) {
+  // @ts-expect-error supportsDynamicImport is not defined in CallerMetadata
   return !!caller?.supportsDynamicImport;
 }
 
-function supportsExportNamespaceFrom(caller) {
+function supportsExportNamespaceFrom(caller: CallerMetadata | undefined) {
+  // @ts-expect-error supportsExportNamespaceFrom is not defined in CallerMetadata
   return !!caller?.supportsExportNamespaceFrom;
 }
 
-function supportsTopLevelAwait(caller) {
+function supportsTopLevelAwait(caller: CallerMetadata | undefined) {
+  // @ts-expect-error supportsTopLevelAwait is not defined in CallerMetadata
   return !!caller?.supportsTopLevelAwait;
 }
 

packages/babel-preset-env/src/normalize-options.ts

@@ -113,7 +113,9 @@ export const checkDuplicateIncludeExcludes = (
   );
 };
 
-const normalizeTargets = (targets): Options["targets"] => {
+const normalizeTargets = (
+  targets: string | string[] | Options["targets"],
+): Options["targets"] => {
   // TODO: Allow to use only query or strings as a targets from next breaking change.
   if (typeof targets === "string" || Array.isArray(targets)) {
     return { browsers: targets };
@@ -125,6 +127,7 @@ export const validateModulesOption = (
   modulesOpt: ModuleOption = ModulesOption.auto,
 ) => {
   v.invariant(
+    // @ts-ignore we have provided fallback for undefined keys
     ModulesOption[modulesOpt.toString()] || modulesOpt === ModulesOption.false,
     `The 'modules' option must be one of \n` +
       ` - 'false' to indicate no module processing\n` +
@@ -140,6 +143,7 @@ export const validateUseBuiltInsOption = (
   builtInsOpt: BuiltInsOption = false,
 ) => {
   v.invariant(
+    // @ts-ignore we have provided fallback for undefined keys
     UseBuiltInsOption[builtInsOpt.toString()] ||
       builtInsOpt === UseBuiltInsOption.false,
     `The 'useBuiltIns' option must be either
@@ -261,7 +265,7 @@ export default function normalizeOptions(opts: Options) {
     spec: v.validateBooleanOption(TopLevelOptions.spec, opts.spec, false),
     targets: normalizeTargets(opts.targets),
     useBuiltIns: useBuiltIns,
-    browserslistEnv: v.validateStringOption(
+    browserslistEnv: v.validateStringOption<string>(
       TopLevelOptions.browserslistEnv,
       opts.browserslistEnv,
     ),

packages/babel-preset-env/src/plugins-compat-data.ts

@@ -7,12 +7,14 @@ const bugfixPluginsFiltered = {};
 
 for (const plugin of Object.keys(plugins)) {
   if (Object.hasOwnProperty.call(availablePlugins, plugin)) {
+    // @ts-ignore
     pluginsFiltered[plugin] = plugins[plugin];
   }
 }
 
 for (const plugin of Object.keys(bugfixPlugins)) {
   if (Object.hasOwnProperty.call(availablePlugins, plugin)) {
+    // @ts-ignore
     bugfixPluginsFiltered[plugin] = bugfixPlugins[plugin];
   }
 }

packages/babel-preset-env/src/polyfills/regenerator.ts

@@ -2,7 +2,7 @@ import { getImportSource, getRequireSource } from "./utils";
 import type { Visitor } from "@babel/traverse";
 import type { PluginObject, PluginPass } from "@babel/core";
 
-function isRegeneratorSource(source) {
+function isRegeneratorSource(source: string) {
   return (
     source === "regenerator-runtime/runtime" ||
     source === "regenerator-runtime/runtime.js"