chore: migrate babel/src to TS (#386)

.eslintrc

@@ -1,8 +1,24 @@
 {
   "extends": "@callstack",
   "rules": {
-      "global-require": "off",
-      "react-native/no-raw-text": "off",
-      "react-native/no-inline-styles": "off"
+    "global-require": "off",
+    "react-native/no-raw-text": "off",
+    "react-native/no-inline-styles": "off",
+    "import/no-extraneous-dependencies": [
+      "error",
+      {
+        "devDependencies": [
+          "**/*.test.{js,ts,jsx,tsx}",
+          "src/{babel,server}/**/*.{js,ts,jsx,tsx}"
+        ]
+      }
+    ]
+  },
+  "settings": {
+    "import/resolver": {
+      "node": {
+        "extensions": [".js", ".jsx", ".ts", ".tsx"]
+      }
+    }
   }
 }

.prettierrc

@@ -0,0 +1,4 @@
+{
+  "trailingComma": "es5",
+  "singleQuote": true
+}

package.json

@@ -34,7 +34,7 @@
   ],
   "scripts": {
     "lint": "eslint --ext .js,.ts,.tsx .",
-    "typecheck": "tsc && flow",
+    "typecheck": "tsc --noEmit && flow",
     "typescript": "dtslint",
     "test": "jest",
     "add-contributor": "all-contributors add",
@@ -59,8 +59,12 @@
     "@callstack/eslint-config": "^4.1.0",
     "@commitlint/config-conventional": "^7.5.0",
     "@release-it/conventional-changelog": "^1.0.2",
-    "@types/react": "^16.8.4",
-    "@typescript-eslint/eslint-plugin": "^1.5.0",
+    "@types/cosmiconfig": "^5.0.3",
+    "@types/dedent": "^0.7.0",
+    "@types/jest": "^24.0.11",
+    "@types/react": "^16.8.12",
+    "@types/react-is": "^16.7.1",
+    "@typescript-eslint/eslint-plugin": "^1.6.0",
     "all-contributors-cli": "^6.1.1",
     "babel-core": "^7.0.0-bridge.0",
     "babel-jest": "^24.5.0",
@@ -73,20 +77,21 @@
     "flow-bin": "^0.94.0",
     "flow-copy-source": "^2.0.3",
     "husky": "^1.3.1",
-    "jest": "^24.5.0",
+    "jest": "^24.7.1",
     "prettier": "^1.16.4",
     "react": "^16.8.3",
     "react-test-renderer": "^16.8.3",
     "release-it": "^12.2.0",
-    "typescript": "^3.3.4000"
+    "typescript": "^3.4.1"
   },
   "dependencies": {
-    "@babel/core": "^7.3.3",
-    "@babel/generator": "^7.3.3",
+    "@babel/core": "^7.4.3",
+    "@babel/generator": "^7.4.0",
     "@babel/plugin-proposal-export-namespace-from": "^7.2.0",
     "@babel/plugin-syntax-dynamic-import": "^7.2.0",
     "@babel/plugin-transform-modules-commonjs": "^7.2.0",
-    "@babel/register": "^7.0.0",
+    "@babel/register": "^7.4.0",
+    "@babel/traverse": "^7.4.3",
     "@emotion/is-prop-valid": "^0.7.3",
     "core-js": "^3.6.3",
     "cosmiconfig": "^5.1.0",
@@ -106,7 +111,8 @@
     "yargs": "^13.2.1"
   },
   "resolutions": {
-    "**/babel-core": "7.0.0-bridge.0"
+    "**/babel-core": "7.0.0-bridge.0",
+    "@types/react": "^16.8.12"
   },
   "husky": {
     "hooks": {

src/__tests__/__snapshots__/babel.test.js.snap

@@ -413,6 +413,9 @@ Dependencies: NA
 
 exports[`transpiles styled template literal with function and component 1`] = `
 "import { styled } from 'linaria/react';
+
+const Heading = () => null;
+
 export const Title =
 /*#__PURE__*/
 styled(Heading)({

src/__tests__/__snapshots__/preval.test.js.snap

@@ -183,7 +183,7 @@ Dependencies: ../slugify
 exports[`evaluates expressions with expressions depending on shared dependency 1`] = `
 "import { styled } from 'linaria/react';
 
-const slugify = require('../slugify');
+const slugify = require('../slugify').default;
 
 const boo = t => slugify(t) + 'boo';
 
@@ -304,7 +304,7 @@ Dependencies: NA
 exports[`evaluates multiple expressions with shared dependency 1`] = `
 "import { styled } from 'linaria/react';
 
-const slugify = require('../slugify');
+const slugify = require('../slugify').default;
 
 const boo = t => slugify(t) + 'boo';
 

src/__tests__/babel.test.js

@@ -51,6 +51,7 @@ it('transpiles styled template literal with function and component', async () =>
   const { code, metadata } = await transpile(
     dedent`
     import { styled } from 'linaria/react';
+    const Heading = () => null;
 
     export const Title = styled(Heading)\`
       font-size: 14px;

src/__tests__/preval.test.js

@@ -1,11 +1,11 @@
 /* eslint-disable no-template-curly-in-string */
-/* @flow */
 
-const path = require('path');
-const babel = require('@babel/core');
-const dedent = require('dedent');
-const stripAnsi = require('strip-ansi');
-const serializer = require('../__utils__/linaria-snapshot-serializer');
+import * as babel from '@babel/core';
+import dedent from 'dedent';
+import { join, resolve } from 'path';
+import stripAnsi from 'strip-ansi';
+
+import serializer from '../__utils__/linaria-snapshot-serializer';
 
 expect.addSnapshotSerializer(serializer);
 
@@ -19,7 +19,7 @@ const babelrc = {
 const transpile = async input => {
   const { code, metadata } = await babel.transformAsync(input, {
     ...babelrc,
-    filename: path.join(__dirname, 'source.js'),
+    filename: join(__dirname, 'source.js'),
   });
 
   // The slug will be machine specific, so replace it with a consistent one
@@ -113,7 +113,7 @@ it('evaluates expressions with expressions depending on shared dependency', asyn
   const { code, metadata } = await transpile(
     dedent`
     import { styled } from 'linaria/react';
-    const slugify = require('../slugify');
+    const slugify = require('../slugify').default;
 
     const boo = t => slugify(t) + 'boo';
     const bar = t => slugify(t) + 'bar';
@@ -134,7 +134,7 @@ it('evaluates multiple expressions with shared dependency', async () => {
   const { code, metadata } = await transpile(
     dedent`
     import { styled } from 'linaria/react';
-    const slugify = require('../slugify');
+    const slugify = require('../slugify').default;
 
     const boo = t => slugify(t) + 'boo';
     const bar = t => slugify(t) + 'bar';
@@ -416,7 +416,7 @@ it('throws codeframe error when evaluation fails', async () => {
 
 it('handles escapes properly', async () => {
   const { code, metadata } = await babel.transformFileAsync(
-    path.resolve(__dirname, '../__fixtures__/escape-character.js'),
+    resolve(__dirname, '../__fixtures__/escape-character.js'),
     babelrc
   );
 
@@ -435,7 +435,7 @@ it('derives display name from filename', async () => {
     `,
     {
       ...babelrc,
-      filename: path.join(__dirname, 'FancyName.js'),
+      filename: join(__dirname, 'FancyName.js'),
     }
   );
 
@@ -454,7 +454,7 @@ it('derives display name from parent folder name', async () => {
     `,
     {
       ...babelrc,
-      filename: path.join(__dirname, 'FancyName/index.js'),
+      filename: join(__dirname, 'FancyName/index.js'),
     }
   );
 
@@ -476,7 +476,7 @@ it("throws if couldn't determine a display name", async () => {
       `,
       {
         ...babelrc,
-        filename: path.join(__dirname, '/.js'),
+        filename: join(__dirname, '/.js'),
       }
     );
   } catch (e) {