chore: update mocks, move configs to jest dir

jest/__mocks__/gatsby.js

@@ -0,0 +1,29 @@
+'use strict';
+
+const React = require('react');
+
+const gatsby = jest.requireActual('gatsby');
+
+module.exports = {
+  ...gatsby,
+  graphql: jest.fn(),
+  Link: jest.fn().mockImplementation(
+    ({
+      activeClassName,
+      activeStyle,
+      getProps,
+      innerRef,
+      ref,
+      replace,
+      to,
+      ...rest
+    }) => (
+      React.createElement('a', {
+        ...rest,
+        href: to,
+      })
+    )
+  ),
+  StaticQuery: jest.fn(),
+  useStaticQuery: jest.fn(),
+};

jest/jest-config.js

@@ -17,5 +17,6 @@ module.exports = {
   globals: {
     __PATH_PREFIX__: ''
   },
-  testURL: 'http://localhost/'
+  testURL: 'http://localhost/',
+  setupFiles: ['<rootDir>/tests/loadershim.js']
 };

jest/jest-preprocess.js

@@ -1,7 +1,11 @@
 'use strict';
 
 const babelOptions = {
-  presets: ['@babel/react', '@babel/env'],
+  presets: [
+    '@babel/react',
+    '@babel/env',
+    'babel-preset-gatsby'
+  ],
   plugins: [
     '@babel/plugin-proposal-optional-chaining',
     '@babel/plugin-proposal-class-properties',

jest/loadershim.js

@@ -0,0 +1,5 @@
+'use strict';
+
+global.___loader = {
+  enqueue: jest.fn(),
+};

package.json

@@ -12,9 +12,9 @@
     "lint:js": "eslint --cache --ext .js,.jsx --ignore-pattern public .",
     "lint:scss": "stylelint \"src/**/*.scss\"",
     "lint": "concurrently \"yarn run lint:js\" \"yarn run lint:scss\" \"yarn flow\"",
-    "test": "jest --config ./tests/jest-config.js",
-    "test:coverage": "jest --coverage --config ./tests/jest-config.js",
-    "test:watch": "jest --watch --config ./tests/jest-config.js",
+    "test": "jest --config ./jest/jest-config.js",
+    "test:coverage": "jest --coverage --config ./jest/jest-config.js",
+    "test:watch": "jest --watch --config ./jest/jest-config.js",
     "release": "standard-version"
   },
   "repository": "https://github.com/alxshelepenok/gatsby-starter-lumen",
@@ -87,6 +87,7 @@
     "@babel/plugin-transform-flow-strip-types": "^7.4.4",
     "@babel/preset-env": "7.4.4",
     "@babel/preset-react": "7.0.0",
+    "babel-preset-gatsby": "0.1.11",
     "autoprefixer": "9.5.1",
     "babel-core": "7.0.0-bridge.0",
     "babel-eslint": "10.0.1",

tests/__mocks__/gatsby.js

@@ -1,10 +0,0 @@
-'use strict';
-
-const gatsby = jest.requireActual('gatsby');
-
-module.exports = {
-  ...gatsby,
-  graphql: jest.fn(),
-  Link: 'Link',
-  StaticQuery: 'StaticQuery'
-};