Jest testing for slate-react (#4459)

* initial skeleton for jest testing

* run in serial mocha, then jest on slate-react only

* run-s without glob patterns https://github.com/yarnpkg/berry/issues/22

* don't run mocha on slate-react package

* use yarn run instead of run-s

babel.config.js

@@ -0,0 +1,9 @@
+// Needed for jest.
+module.exports = {
+  inputSourceMap: true,
+  presets: [
+    '@babel/preset-typescript',
+    ['@babel/preset-env', { targets: { node: 'current' } }],
+    '@babel/preset-react',
+  ],
+}

jest.config.js

@@ -0,0 +1,5 @@
+const config = {
+  testMatch: ['<rootDir>/packages/slate-react/test/**/*.{js,ts,tsx,jsx}'],
+}
+
+module.exports = config

package.json

@@ -27,10 +27,12 @@
     "internal:release:next": "yarn prerelease && yarn changeset publish --tag next",
     "serve": "cd ./site && next",
     "start": "npm-run-all --parallel --print-label watch serve",
-    "test": "mocha --require ./config/babel/register.cjs './packages/*/test/**/*.{js,ts}'",
+    "test": "yarn run test:mocha && yarn run test:jest",
     "test:custom": "mocha --require ./config/babel/register.cjs ./packages/slate/test/index.js",
     "test:inspect": "yarn test --inspect-brk",
     "test:integration": "run-p -r serve cypress:run",
+    "test:mocha": "mocha --require ./config/babel/register.cjs ./packages/{slate,slate-history,slate-hyperscript}/test/**/*.{js,ts}",
+    "test:jest": "jest --config jest.config.js",
     "watch": "yarn build:rollup --watch",
     "cypress:run": "cypress run",
     "cypress:open": "cypress open"
@@ -52,6 +54,7 @@
     "@changesets/changelog-github": "^0.3.0",
     "@changesets/cli": "^2.14.1",
     "@testing-library/cypress": "^8.0.0",
+    "@types/jest": "27.0.1",
     "@types/lodash": "^4.14.149",
     "@types/mocha": "^5.2.7",
     "@types/node": "^12.12.14",
@@ -60,6 +63,7 @@
     "@typescript-eslint/eslint-plugin": "^2.9.0",
     "@typescript-eslint/parser": "^2.9.0",
     "babel-eslint": "^10.0.3",
+    "babel-jest": "27.0.6",
     "babel-plugin-dev-expression": "^0.2.2",
     "babel-plugin-module-resolver": "^3.1.1",
     "cypress": "^8.3.0",
@@ -73,6 +77,7 @@
     "image-extensions": "^1.1.0",
     "is-hotkey": "^0.1.6",
     "is-url": "^1.2.2",
+    "jest": "27.0.6",
     "lerna": "^3.19.0",
     "lint-staged": ">=10",
     "lodash": "^4.17.4",

packages/slate-react/test/index.js

@@ -9,7 +9,7 @@ describe('slate-react', () => {
   describe('Editable', () => {
     describe('decorate', () => {
       // stub out some DOM stuff to avoid crashes
-      before(() => {
+      beforeEach(() => {
         const jsdom = new JSDOM()
         global.window = jsdom.window
         global.document = jsdom.window.document