add basic jest support

Author: liorheber

enzyme.config.js

@@ -0,0 +1,4 @@
+const Enzyme = require('enzyme');
+const Adapter = require('enzyme-adapter-react-16');
+
+Enzyme.configure({ adapter: new Adapter() });

package.json

@@ -14,19 +14,30 @@
     "@babel/preset-env": "^7.8.4",
     "@babel/preset-react": "^7.8.3",
     "@preconstruct/cli": "^1.1.7",
-    "prettier": "1.19.1"
+    "enzyme": "^3.11.0",
+    "enzyme-adapter-react-16": "^1.15.2",
+    "enzyme-to-json": "^3.4.4",
+    "jest": "^25.1.0",
+    "prettier": "1.19.1",
+    "react": "^16.12.0"
   },
   "preconstruct": {
     "packages": [
       "packages/*",
       "!packages/docs"
     ]
   },
+  "jest": {
+    "moduleDirectories": ["node_modules"],
+    "setupFiles": [
+      "./enzyme.config.js"
+    ]
+  },
   "scripts": {
     "postinstall": "preconstruct dev",
     "build": "preconstruct build",
     "release": "preconstruct build",
-    "test": "echo skip",
+    "test": "jest",
     "prettier": "prettier --check ./packages/**/*.js --ignore-path .gitignore",
     "prettier:fix": "prettier --check ./packages/**/*.js --ignore-path .gitignore --write"
   }

packages/core/tests/__snapshots__/index.spec.js.snap

@@ -0,0 +1,7 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`core component will render 1`] = `
+<div>
+  HelloWorld
+</div>
+`;

packages/core/tests/index.spec.js

@@ -0,0 +1,11 @@
+import React from "react";
+import { shallow } from "enzyme";
+import HelloWorld from "../src";
+import toJson from "enzyme-to-json";
+
+describe("core component", () => {
+  test("will render", () => {
+    const cmp = shallow(<HelloWorld />);
+    expect(toJson((cmp))).toMatchSnapshot();
+  });
+});