Migrate Reselect source to TS

.babelrc.js

@@ -1,8 +1,19 @@
-const { BABEL_ENV, NODE_ENV } = process.env
-const cjs = BABEL_ENV === 'cjs' || NODE_ENV === 'test'
+const { NODE_ENV, BABEL_ENV } = process.env
+const cjs = NODE_ENV === 'test' || BABEL_ENV === 'commonjs'
 
 module.exports = {
   presets: [
-    ['@babel/env', { loose: true, modules: cjs ? 'cjs' : false }]
+    [
+      '@babel/preset-env',
+      {
+        targets: {
+          ie: 11
+        },
+        loose: true,
+        modules: cjs ? 'cjs' : false
+      }
+    ],
+    '@babel/preset-typescript'
   ],
+  plugins: [cjs && ['@babel/transform-modules-commonjs']].filter(Boolean)
 }

.eslintignore

@@ -0,0 +1,4 @@
+lib
+es
+dist
+node_modules

.github/workflows/build-and-test-types.yml

@@ -33,7 +33,7 @@ jobs:
         run: npm run test:cov
 
       - name: Compile
-        run: npm run compile
+        run: npm run build
 
       - name: Report to Coveralls
         uses: coverallsapp/github-action@master

.gitignore

@@ -11,3 +11,4 @@ typescript_test/should_not_compile/index.js
 typescript_test/common.js
 flow_test/should_fail/flow-typed/index.js.flow
 flow_test/should_pass/flow-typed/index.js.flow
+reselect-builds/

.prettierrc.json

@@ -0,0 +1,7 @@
+{
+  "semi": false,
+  "singleQuote": true,
+  "tabWidth": 2,
+  "trailingComma": "none",
+  "arrowParens": "avoid"
+}

jest.config.js

@@ -0,0 +1,14 @@
+/** @type {import('@ts-jest/dist/types').InitialOptionsTsJest} */
+
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  coverageDirectory: './coverage/',
+  collectCoverage: true,
+  testRegex: '(/test/.*(js|ts))$',
+  globals: {
+    'ts-jest': {
+      tsconfig: './test/tsconfig.json'
+    }
+  }
+}