Fix test

jest.json

@@ -1,5 +1,6 @@
 {
   "transform": {
     "^.+\\.tsx?$": "ts-jest"
-  }
+  },
+  "setupFiles": ["<rootDir>/test/setup.js"]
 }

test/setup.js

@@ -0,0 +1,36 @@
+function dummy() {
+  // Don't do anything
+}
+
+window.__ELECTRON_ONLY__ = {
+  readFile: dummy,
+  readdir: dummy,
+  writeFile: dummy,
+  unlinkFile: dummy,
+  stat: dummy,
+  mkdir: dummy,
+  readFileType: dummy,
+  readFileTypeFromBuffer: dummy,
+  showOpenDialog: dummy,
+  showSaveDialog: dummy,
+  openExternal: dummy,
+  parseCSON: dummy,
+  stringifyCSON: dummy,
+  openNewWindow: dummy,
+  openContextMenu: dummy,
+  getPathByName: dummy,
+  addIpcListener: dummy,
+  sendIpcMessage: dummy,
+  removeIpcListener: dummy,
+  removeAllIpcListeners: dummy,
+  setAsDefaultProtocolClient: dummy,
+  removeAsDefaultProtocolClient: dummy,
+  isDefaultProtocolClient: dummy,
+  getWebContentsById: dummy,
+  setTrafficLightPosition: dummy,
+  convertHtmlStringToPdfBuffer: dummy,
+  setCookie: dummy,
+  getCookie: dummy,
+  removeCookie: dummy,
+  got: dummy,
+}