Prepare repository for gradual flow->ts migration (babel#12317)

Co-authored-by: Bogdan Savluk <savluk.bogdan@gmail.com>

.eslintignore

@@ -9,6 +9,7 @@ packages/babel-runtime-corejs2
 packages/babel-runtime-corejs3
 packages/*/node_modules
 packages/*/lib
+packages/*/dts
 packages/*/dist
 packages/*/test/fixtures
 packages/*/test/tmp

.eslintrc.js

@@ -19,11 +19,24 @@ module.exports = {
     node: true,
   },
   overrides: [
+    {
+      files: ["**/*.ts"],
+      parser: "@typescript-eslint/parser",
+      plugins: ["@typescript-eslint"],
+      rules: {
+        "no-unused-vars": "off",
+        "@typescript-eslint/no-unused-vars": "error",
+        "no-dupe-class-members": "off",
+        "@typescript-eslint/no-dupe-class-members": "error",
+        "no-undef": "off",
+        "no-redeclare": "off",
+      },
+    },
     {
       files: [
-        "packages/*/src/**/*.js",
-        "codemods/*/src/**/*.js",
-        "eslint/*/src/**/*.js",
+        "packages/*/src/**/*.{js,ts}",
+        "codemods/*/src/**/*.{js,ts}",
+        "eslint/*/src/**/*.{js,ts}",
       ],
       rules: {
         "@babel/development/no-undefined-identifier": "error",
@@ -37,7 +50,7 @@ module.exports = {
         "packages/*/test/**/*.js",
         "codemods/*/test/**/*.js",
         "eslint/*/test/**/*.js",
-        "packages/babel-helper-transform-fixture-test-runner/src/helpers.js",
+        "packages/babel-helper-transform-fixture-test-runner/src/helpers.{ts,js}",
         "test/**/*.js",
       ],
       env: {
@@ -53,15 +66,15 @@ module.exports = {
       },
     },
     {
-      files: ["packages/babel-plugin-*/src/index.js"],
+      files: ["packages/babel-plugin-*/src/index.{js,ts}"],
       excludedFiles: ["packages/babel-plugin-transform-regenerator/**/*.js"],
       rules: {
         "@babel/development/plugin-name": "error",
         eqeqeq: ["error", "always", { null: "ignore" }],
       },
     },
     {
-      files: ["packages/babel-parser/src/**/*.js"],
+      files: ["packages/babel-parser/src/**/*.{js,ts}"],
       rules: {
         "@babel/development-internal/dry-error-messages": [
           "error",

.flowconfig

@@ -16,6 +16,7 @@ lib/parser.js
 lib/third-party-libs.js.flow
 lib/preset-modules.js.flow
 packages/babel-types/lib/index.js.flow
+lib/babel-packages.js.flow
 
 [options]
 include_warnings=true

.gitignore

@@ -70,3 +70,10 @@ packages/babel-standalone/babel.min.js
 /eslint/*/LICENSE
 !/packages/babel-eslint-plugin/LICENSE
 /.vscode
+
+/tsconfig.json
+/packages/*/tsconfig.json
+/packages/*/tsconfig.tsbuildinfo
+/packages/*/dts
+/codemods/*/dts
+/eslint/*/dts

.prettierrc

@@ -10,15 +10,14 @@
   "printWidth": 80,
   "overrides": [{
     "files": [
-      "**/codemods/*/src/**/*.js",
+      "**/codemods/*/src/**/*.{js,ts}",
       "**/codemods/*/test/**/*.js",
-      "**/packages/*/src/**/*.js",
+      "**/packages/*/src/**/*.{js,ts}",
       "**/packages/*/test/**/*.js",
-      "**/eslint/*/src/**/*.js",
+      "**/eslint/*/src/**/*.{js,ts}",
       "**/eslint/*/test/**/*.js"
     ],
     "options": {
-      "parser": "babel",
       "trailingComma": "all"
     }
   }]

Gulpfile.js

@@ -9,6 +9,7 @@ const fancyLog = require("fancy-log");
 const filter = require("gulp-filter");
 const gulp = require("gulp");
 const path = require("path");
+const fs = require("fs");
 const rollup = require("rollup");
 const rollupBabel = require("@rollup/plugin-babel").default;
 const rollupBabelSource = require("./scripts/rollup-plugin-babel-source");
@@ -19,7 +20,7 @@ const rollupNodeResolve = require("@rollup/plugin-node-resolve").default;
 const rollupReplace = require("@rollup/plugin-replace");
 const { terser: rollupTerser } = require("rollup-plugin-terser");
 
-const defaultSourcesGlob = "./@(codemods|packages|eslint)/*/src/**/*.js";
+const defaultSourcesGlob = "./@(codemods|packages|eslint)/*/src/**/*.{js,ts}";
 
 function swapSrcWithLib(srcPath) {
   const parts = srcPath.split(path.sep);
@@ -28,7 +29,12 @@ function swapSrcWithLib(srcPath) {
 }
 
 function getIndexFromPackage(name) {
-  return `${name}/src/index.js`;
+  try {
+    fs.statSync(`./${name}/src/index.ts`);
+    return `${name}/src/index.ts`;
+  } catch {
+    return `${name}/src/index.js`;
+  }
 }
 
 function compilationLogger() {
@@ -121,8 +127,10 @@ function buildRollup(packages) {
             babelrc: false,
             babelHelpers: "bundled",
             extends: "./babel.config.js",
+            extensions: [".mjs", ".cjs", ".ts", ".js"],
           }),
           rollupNodeResolve({
+            extensions: [".mjs", ".cjs", ".ts", ".js", ".json"],
             browser: nodeResolveBrowser,
             preferBuiltins: true,
             //todo: remove when semver and source-map are bumped to latest versions
@@ -142,7 +150,7 @@ function buildRollup(packages) {
           rollupJson(),
           rollupNodePolyfills({
             sourceMap: sourcemap,
-            include: "**/*.js",
+            include: "**/*.{js,ts}",
           }),
         ],
       });

Makefile

@@ -36,6 +36,9 @@ build-bundle: clean clean-lib
 build-bundle-ci: bootstrap-only
 	$(MAKE) build-bundle
 
+generate-tsconfig:
+	$(NODE) scripts/generators/tsconfig.js
+
 generate-standalone:
 	$(NODE) packages/babel-standalone/scripts/generate.js
 
@@ -85,12 +88,15 @@ watch: build-no-bundle
 	BABEL_ENV=development $(YARN) gulp watch
 
 code-quality-ci: build-no-bundle-ci
-	$(MAKE) flowcheck-ci lint-ci
+	$(MAKE) tscheck flowcheck-ci lint-ci
 
 flowcheck-ci:
 	$(MAKE) flow
 
-code-quality: flow lint
+code-quality: tscheck flow lint
+
+tscheck: generate-tsconfig
+	$(YARN) tsc -b .
 
 flow:
 	$(YARN) flow check --strip-root
@@ -109,15 +115,15 @@ check-compat-data-ci:
 lint: lint-js lint-ts
 
 lint-js:
-	BABEL_ENV=test $(YARN) eslint scripts $(SOURCES) '*.js' --format=codeframe
+	BABEL_ENV=test $(YARN) eslint scripts $(SOURCES) '*.{js,ts}' --format=codeframe --ext .js,.cjs,.mjs,.ts
 
 lint-ts:
 	scripts/lint-ts-typings.sh
 
 fix: fix-json fix-js
 
 fix-js:
-	$(YARN) eslint scripts $(SOURCES) '*.js' --format=codeframe --fix
+	$(YARN) eslint scripts $(SOURCES) '*.{js,ts}' --format=codeframe --ext .js,.cjs,.mjs,.ts --fix
 
 fix-json:
 	$(YARN) prettier "{$(COMMA_SEPARATED_SOURCES)}/*/test/fixtures/**/options.json" --write --loglevel warn
@@ -136,6 +142,10 @@ clean: test-clean
 	rm -rf packages/*/npm-debug*
 	rm -rf node_modules/.cache
 
+clean-tsconfig:
+	rm -f tsconfig.json
+	rm -f packages/*/tsconfig.json
+
 test-clean:
 	$(foreach source, $(SOURCES), \
 		$(call clean-source-test, $(source)))
@@ -211,12 +221,17 @@ clone-license:
 prepublish-build: clean-lib clean-runtime-helpers
 	NODE_ENV=production BABEL_ENV=production $(MAKE) build-bundle
 	$(MAKE) prepublish-build-standalone clone-license
+	# We don't want to publish .d.ts files yet
+	rm -rf packages/*/dts
 
 prepublish:
 	$(MAKE) check-yarn-bug-1882
 	$(MAKE) bootstrap-only
 	$(MAKE) prepublish-build
 	IS_PUBLISH=true $(MAKE) test
+	# We don't want to use modern TS features in published @babel/types typings,
+	# to avoid breaking backward compatibility.
+	PRODUCTION_TS_TYPES=true $(MAKE) build-typings
 
 new-version:
 	git pull --rebase
@@ -271,7 +286,7 @@ clean-runtime-helpers:
 	rm -f packages/babel-runtime-corejs3/helpers/**/*.js
 	rm -rf packages/babel-runtime-corejs2/core-js
 
-clean-all:
+clean-all: clean-tsconfig
 	rm -rf node_modules
 	rm -rf package-lock.json
 	rm -rf .changelog

babel.config.js

@@ -103,6 +103,10 @@ module.exports = function (api) {
       .filter(Boolean)
       .map(normalize),
     presets: [
+      [
+        "@babel/preset-typescript",
+        { onlyRemoveTypeImports: true, allowDeclareFields: true },
+      ],
       ["@babel/env", envOpts],
       ["@babel/preset-flow", { allowDeclareFields: true }],
     ],

package.json

@@ -27,13 +27,16 @@
     "@babel/plugin-transform-runtime": "^7.12.0",
     "@babel/preset-env": "^7.12.0",
     "@babel/preset-flow": "^7.10.4",
+    "@babel/preset-typescript": "^7.12.1",
     "@babel/register": "^7.12.0",
     "@babel/runtime": "^7.12.0",
     "@rollup/plugin-babel": "^5.2.0",
     "@rollup/plugin-commonjs": "^13.0.0",
     "@rollup/plugin-json": "^4.1.0",
     "@rollup/plugin-node-resolve": "^9.0.0",
     "@rollup/plugin-replace": "^2.3.3",
+    "@typescript-eslint/eslint-plugin": "^4.6.1",
+    "@typescript-eslint/parser": "^4.6.1",
     "babel-plugin-transform-charcodes": "^0.2.0",
     "chalk": "^2.4.2",
     "charcodes": "^0.2.0",
@@ -61,7 +64,7 @@
     "rollup-plugin-terser": "^7.0.0",
     "test262-stream": "^1.3.0",
     "through2": "^2.0.0",
-    "typescript": "^3.6.3"
+    "typescript": "^4.0.5"
   },
   "workspaces": [
     "codemods/*",
@@ -78,7 +81,7 @@
     "yarn": ">=1.4.0"
   },
   "lint-staged": {
-    "*.js": [
+    "*.{js,ts}": [
       "eslint --format=codeframe"
     ]
   },