convert @babel/helper-compilation-targets to typescript (#13218)

Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

lib/babel-packages.js.flow

@@ -216,3 +216,7 @@ declare module "@babel/helper-module-transforms" {
 declare module "@babel/plugin-transform-classes" {
   declare module.exports: any;
 }
+
+declare module "@babel/helper-compilation-targets" {
+  declare module.exports: any;
+}

packages/babel-helper-compilation-targets/package.json

@@ -30,6 +30,8 @@
     "@babel/core": "^7.0.0"
   },
   "devDependencies": {
-    "@babel/core": "workspace:*"
+    "@babel/core": "workspace:*",
+    "@babel/helper-plugin-test-runner": "workspace:*",
+    "@types/semver": "^5.5.0"
   }
 }

packages/babel-helper-compilation-targets/src/debug.ts

@@ -1,5 +1,3 @@
-// @flow
-
 import semver from "semver";
 import { prettifyVersion } from "./pretty";
 import {
@@ -7,16 +5,16 @@ import {
   isUnreleasedVersion,
   getLowestImplementedVersion,
 } from "./utils";
-import type { Targets } from "./types";
+import type { Target, Targets } from "./types";
 
 export function getInclusionReasons(
   item: string,
   targetVersions: Targets,
   list: { [key: string]: Targets },
 ) {
-  const minVersions = list[item] || {};
+  const minVersions = list[item] || ({} as Targets);
 
-  return Object.keys(targetVersions).reduce((result, env) => {
+  return (Object.keys(targetVersions) as Target[]).reduce((result, env) => {
     const minVersion = getLowestImplementedVersion(minVersions, env);
     const targetVersion = targetVersions[env];
 

packages/babel-helper-compilation-targets/src/filter-items.ts

@@ -1,5 +1,3 @@
-// @flow
-
 import semver from "semver";
 
 import pluginsCompatData from "@babel/compat-data/plugins";
@@ -12,7 +10,7 @@ import {
 } from "./utils";
 
 export function targetsSupported(target: Targets, support: Targets) {
-  const targetEnvironments = Object.keys(target);
+  const targetEnvironments = Object.keys(target) as Array<keyof Targets>;
 
   if (targetEnvironments.length === 0) {
     return false;
@@ -65,9 +63,9 @@ export function isRequired(
     includes,
     excludes,
   }: {
-    compatData?: { [feature: string]: Targets },
-    includes?: Set<string>,
-    excludes?: Set<string>,
+    compatData?: { [feature: string]: Targets };
+    includes?: Set<string>;
+    excludes?: Set<string>;
   } = {},
 ) {
   if (excludes?.has(name)) return false;

packages/babel-helper-compilation-targets/src/index.ts

@@ -1,5 +1,3 @@
-// @flow
-
 import browserslist from "browserslist";
 import { findSuggestion } from "@babel/helper-validator-option";
 import browserModulesData from "@babel/compat-data/native-modules";
@@ -26,6 +24,7 @@ export { TargetNames };
 
 const ESM_SUPPORT = browserModulesData["es6.module"];
 
+declare const PACKAGE_JSON: { name: string; version: string };
 const v = new OptionValidator(PACKAGE_JSON.name);
 
 function validateTargetNames(targets: Targets): TargetsTuple {
@@ -39,17 +38,17 @@ function validateTargetNames(targets: Targets): TargetsTuple {
     }
   }
 
-  return (targets: any);
+  return targets as any;
 }
 
-export function isBrowsersQueryValid(browsers: mixed): boolean %checks {
+export function isBrowsersQueryValid(browsers: unknown): boolean {
   return (
     typeof browsers === "string" ||
     (Array.isArray(browsers) && browsers.every(b => typeof b === "string"))
   );
 }
 
-function validateBrowsers(browsers: Browsers | void) {
+function validateBrowsers(browsers: Browsers | undefined) {
   v.invariant(
     browsers === undefined || isBrowsersQueryValid(browsers),
     `'${String(browsers)}' is not a valid browserslist query`,
@@ -59,7 +58,7 @@ function validateBrowsers(browsers: Browsers | void) {
 }
 
 function getLowestVersions(browsers: Array<string>): Targets {
-  return browsers.reduce((all: Object, browser: string): Object => {
+  return browsers.reduce((all: any, browser: string): any => {
     const [browserName, browserVersion] = browser.split(" ");
     const normalizedBrowserName = browserNameMap[browserName];
 
@@ -102,7 +101,7 @@ function getLowestVersions(browsers: Array<string>): Targets {
 }
 
 function outputDecimalWarning(
-  decimalTargets: Array<{| target: string, value: string |}>,
+  decimalTargets: Array<{ target: string; value: string }>,
 ): void {
   if (!decimalTargets.length) {
     return;
@@ -152,7 +151,7 @@ function generateTargets(inputTargets: InputTargets): Targets {
   const input = { ...inputTargets };
   delete input.esmodules;
   delete input.browsers;
-  return ((input: any): Targets);
+  return input as any as Targets;
 }
 
 function resolveTargets(queries: Browsers): Targets {
@@ -162,20 +161,17 @@ function resolveTargets(queries: Browsers): Targets {
 
 type GetTargetsOption = {
   // This is not the path of the config file, but the path where start searching it from
-  configPath?: string,
-
+  configPath?: string;
   // The path of the config file
-  configFile?: string,
-
+  configFile?: string;
   // The env to pass to browserslist
-  browserslistEnv?: string,
-
+  browserslistEnv?: string;
   // true to disable config loading
-  ignoreBrowserslistConfig?: boolean,
+  ignoreBrowserslistConfig?: boolean;
 };
 
 export default function getTargets(
-  inputTargets: InputTargets = {},
+  inputTargets: InputTargets = {} as InputTargets,
   options: GetTargetsOption = {},
 ): Targets {
   let { browsers, esmodules } = inputTargets;
@@ -243,7 +239,7 @@ export default function getTargets(
   }
 
   // Parse remaining targets
-  const result: Targets = {};
+  const result: Targets = {} as Targets;
   const decimalWarnings = [];
   for (const target of Object.keys(targets).sort()) {
     const value = targets[target];

packages/babel-helper-compilation-targets/src/options.ts

@@ -1,5 +1,3 @@
-// @flow
-
 export const TargetNames = {
   node: "node",
   chrome: "chrome",

packages/babel-helper-compilation-targets/src/pretty.ts

@@ -1,5 +1,6 @@
 import semver from "semver";
 import { unreleasedLabels } from "./targets";
+import type { Targets } from "./types";
 
 export function prettifyVersion(version: string) {
   if (typeof version !== "string") {
@@ -32,5 +33,5 @@ export function prettifyTargets(targets: Targets): Targets {
 
     results[target] = value;
     return results;
-  }, {});
+  }, {} as Targets);
 }

packages/babel-helper-compilation-targets/src/types.ts

@@ -1,5 +1,3 @@
-// @flow
-
 // Targets
 export type Target =
   | "node"
@@ -15,24 +13,21 @@ export type Target =
   | "samsung";
 
 export type Targets = {
-  [target: Target]: string,
+  [target in Target]: string;
 };
 
-export type TargetsTuple = {|
-  [target: Target]: string,
-|};
+export type TargetsTuple = {
+  [target in Target]: string;
+};
 
-export type Browsers = string | $ReadOnlyArray<string>;
+export type Browsers = string | ReadonlyArray<string>;
 
 export type InputTargets = {
-  ...Targets,
-
-  browsers?: Browsers,
-
+  browsers?: Browsers;
   // When `true`, this completely replaces the `browsers` option.
   // When `intersect`, this is intersected with the `browsers`
   // option (giving the higher browsers as the result).
   // TODO(Babel 8): Make `true` behave like `intersect` and
   // remove `intersect`.
-  esmodules?: boolean | "intersect",
-};
+  esmodules?: boolean | "intersect";
+} & Targets;

packages/babel-helper-compilation-targets/src/utils.ts

@@ -1,14 +1,18 @@
-// @flow
 import semver from "semver";
 import { OptionValidator } from "@babel/helper-validator-option";
 import { unreleasedLabels } from "./targets";
 import type { Target, Targets } from "./types";
 
+declare const PACKAGE_JSON: { name: string; version: string };
+
 const versionRegExp = /^(\d+|\d+.\d+)$/;
 
 const v = new OptionValidator(PACKAGE_JSON.name);
 
-export function semverMin(first: ?string, second: string): string {
+export function semverMin(
+  first: string | undefined | null,
+  second: string,
+): string {
   return first && semver.lt(first, second) ? first : second;
 }
 
@@ -46,6 +50,7 @@ export function getLowestUnreleased(a: string, b: string, env: string): string {
   const unreleasedLabel = unreleasedLabels[env];
   const hasUnreleased = [a, b].some(item => item === unreleasedLabel);
   if (hasUnreleased) {
+    // @ts-expect-error todo(flow->ts): probably a bug - types of a hasUnreleased to not overlap
     return a === hasUnreleased ? b : a || b;
   }
   return semverMin(a, b);

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

@@ -27,7 +27,6 @@ export const logPlugin = (
     if (!first) formattedTargets += `,`;
     first = false;
     formattedTargets += ` ${target}`;
-    // $FlowIgnore
     if (support[target]) formattedTargets += ` < ${support[target]}`;
   }
   formattedTargets += ` }`;

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

@@ -249,11 +249,11 @@ function getLocalTargets(
 `);
   }
 
-  return getTargets(
-    // $FlowIgnore optionsTargets doesn't have an "uglify" property anymore
-    (optionsTargets: InputTargets),
-    { ignoreBrowserslistConfig, configPath, browserslistEnv },
-  );
+  return getTargets((optionsTargets: InputTargets), {
+    ignoreBrowserslistConfig,
+    configPath,
+    browserslistEnv,
+  });
 }
 
 function supportsStaticESM(caller) {

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

@@ -111,7 +111,7 @@ export const checkDuplicateIncludeExcludes = (
   );
 };
 
-const normalizeTargets = targets => {
+const normalizeTargets = (targets): $PropertyType<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 };

packages/babel-preset-env/src/types.js

@@ -32,7 +32,7 @@ export type Options = {
   modules: ModuleOption,
   shippedProposals: boolean,
   spec: boolean,
-  targets: { ...InputTargets, uglify?: boolean },
+  targets: { ...InputTargets, uglify?: boolean, esmodules?: boolean },
   useBuiltIns: BuiltInsOption,
   browserslistEnv: string,
 };

tsconfig.json

@@ -6,6 +6,7 @@
     "./packages/babel-core/src/**/*.ts",
     "./packages/babel-generator/src/**/*.ts",
     "./packages/babel-helper-annotate-as-pure/src/**/*.ts",
+    "./packages/babel-helper-compilation-targets/src/**/*.ts",
     "./packages/babel-helper-create-regexp-features-plugin/src/**/*.ts",
     "./packages/babel-helper-explode-assignable-expression/src/**/*.ts",
     "./packages/babel-helper-fixtures/src/**/*.ts",
@@ -49,6 +50,9 @@
       "@babel/helper-annotate-as-pure": [
         "./packages/babel-helper-annotate-as-pure/src"
       ],
+      "@babel/helper-compilation-targets": [
+        "./packages/babel-helper-compilation-targets/src"
+      ],
       "@babel/helper-create-regexp-features-plugin": [
         "./packages/babel-helper-create-regexp-features-plugin/src"
       ],

yarn.lock

@@ -410,7 +410,9 @@ __metadata:
   dependencies:
     "@babel/compat-data": "workspace:^7.13.15"
     "@babel/core": "workspace:*"
+    "@babel/helper-plugin-test-runner": "workspace:*"
     "@babel/helper-validator-option": "workspace:^7.12.17"
+    "@types/semver": ^5.5.0
     browserslist: ^4.14.5
     semver: "condition:BABEL_8_BREAKING ? ^7.3.4 : ^6.3.0"
   peerDependencies:
@@ -4243,7 +4245,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/semver@npm:^5.4.0":
+"@types/semver@npm:^5.4.0, @types/semver@npm:^5.5.0":
   version: 5.5.0
   resolution: "@types/semver@npm:5.5.0"
   checksum: df74589466e171c36dd868b760609e518830f212134c238674ddd6eb83653368c59f4510aa6523b7692ec99c5d8ab40b818e30f9d65e0df97c56bdbacef06661