add jest test

.babelrc

@@ -0,0 +1,3 @@
+{
+  "presets": ["es2015", "react"]
+}

jest-setup.js

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

package.json

@@ -11,12 +11,15 @@
     "gatsby-source-filesystem": "^1.5.39",
     "gatsby-transformer-json": "^1.0.20",
     "lerna": "^2.11.0",
+    "react": "16.4.2",
     "react-helmet": "^5.2.0",
     "styled-components": "^3.3.3"
   },
   "devDependencies": {
     "prettier": "^1.12.0",
-    "babel-jest": "^23.4.2"
+    "babel-jest": "^23.4.2",
+    "enzyme": "^3.4.1",
+    "enzyme-adapter-react-16": "^1.2.0"
   },
   "keywords": [
     "gatsby"
@@ -26,7 +29,7 @@
     "run:blog": "cd packages/blog && yarn develop",
     "run:shop": "cd packages/shop && yarn develop",
     "run:all": "npm-run-all --parallel run:blog run:shop",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "jest test"
   },
   "jest": {
     "transform": {
@@ -36,6 +39,9 @@
     "testPathIgnorePatterns": [
       "/node_modules/",
       "/.cache/"
+    ],
+    "setupFiles": [
+      "./jest-setup.js"
     ]
   },
   "repository": {

packages/blog/src/pages/blogitem.test.js

@@ -0,0 +1,21 @@
+import React from 'react'
+import { shallow } from 'enzyme'
+import BlogItem from './blogItem'
+
+describe('Layout component', () => {
+  const mockProps = {
+    pathContext: {
+      data: {
+        title: "mock title",
+        content: "mock content",
+        href: "google.com",
+      },
+    },
+  }
+
+  it('should render', () => {
+    const wrapper = shallow(<BlogItem {...mockProps} />)
+
+    expect(wrapper)
+  })
+})