fix(test): enable babel-jest to transform JSX (#2)

babel-jest requires babel config to be stored in .js file
to transform JSX expressions via @babel/preset-react.
See jestjs/jest#6229 (comment)

packages/web-ssr-server/babel.config.js

@@ -0,0 +1,12 @@
+// Putting babel's configuration to 'babel.config.js' instead of '.babelrc'
+// enables babel-jest to transform JSX via @babel/preset-react:
+// https://github.com/facebook/jest/issues/6229#issuecomment-403539460
+module.exports = {
+  ignore: ['/node_modules/(?!(shared|web-client))'],
+  plugins: [
+    '@babel/plugin-proposal-class-properties',
+    '@babel/plugin-proposal-object-rest-spread',
+    'babel-plugin-transform-es2015-modules-commonjs',
+  ],
+  presets: ['@babel/preset-react'],
+};

packages/web-ssr-server/resources/jest/jest.config.js

@@ -9,4 +9,5 @@ module.exports = {
   transform: {
     '^.+\\.jsx?$': 'babel-jest',
   },
+  transformIgnorePatterns: ['/node_modules/(?!(shared|web-client))'],
 };