Implement back and forth navigation (#9301)

- Closes enso-org/cloud-v2#940

app/ide-desktop/lib/assets/arrow_left.svg

@@ -0,0 +1,4 @@
+<svg style="transform: rotate(180deg)" height="24" width="24" fill="none" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"
+    viewBox="0 0 24 24" stroke="currentColor" xmlns="http://www.w3.org/2000/svg" >
+    <path d="M13 9l3 3m0 0l-3 3m3-3H8m13 0a9 9 0 11-18 0 9 9 0 0118 0z" />
+</svg>

app/ide-desktop/lib/assets/arrow_right.svg

@@ -1,4 +1,4 @@
 <svg height="24" width="24" fill="none" stroke-linecap="round" stroke-linejoin="round" stroke-width="2"
-    viewBox="0 0 24 24" stroke="currentColor" xmlns="http://www.w3.org/2000/svg">
+    viewBox="0 0 24 24" stroke="currentColor" xmlns="http://www.w3.org/2000/svg" >
     <path d="M13 9l3 3m0 0l-3 3m3-3H8m13 0a9 9 0 11-18 0 9 9 0 0118 0z" />
 </svg>

app/ide-desktop/lib/client/src/index.ts

@@ -306,6 +306,7 @@ class App {
                 }
                 const window = new electron.BrowserWindow(windowPreferences)
                 window.setMenuBarVisibility(false)
+
                 if (this.args.groups.debug.options.devTools.value) {
                     window.webContents.openDevTools()
                 }
@@ -397,6 +398,15 @@ class App {
                 }
             }
         )
+
+        // Handling navigation events from renderer process
+        electron.ipcMain.on(ipc.Channel.goBack, () => {
+            this.window?.webContents.goBack()
+        })
+
+        electron.ipcMain.on(ipc.Channel.goForward, () => {
+            this.window?.webContents.goForward()
+        })
     }
 
     /** The server port. In case the server was not started, the port specified in the configuration

app/ide-desktop/lib/client/src/ipc.ts

@@ -23,6 +23,8 @@ export enum Channel {
     saveAccessToken = 'save-access-token',
     /** Channel for importing a project or project bundle from the given path. */
     importProjectFromPath = 'import-project-from-path',
+    goBack = 'go-back',
+    goForward = 'go-forward',
     /** Channel for selecting files and directories using the system file browser. */
     openFileBrowser = 'open-file-browser',
 }

app/ide-desktop/lib/client/src/preload.ts

@@ -21,6 +21,8 @@ const AUTHENTICATION_API_KEY = 'authenticationApi'
  * window. */
 const FILE_BROWSER_API_KEY = 'fileBrowserApi'
 
+const NAVIGATION_API_KEY = 'navigationApi'
+
 // =============================
 // === importProjectFromPath ===
 // =============================
@@ -37,6 +39,15 @@ const BACKEND_API = {
 }
 electron.contextBridge.exposeInMainWorld(BACKEND_API_KEY, BACKEND_API)
 
+electron.contextBridge.exposeInMainWorld(NAVIGATION_API_KEY, {
+    goBack: () => {
+        electron.ipcRenderer.send(ipc.Channel.goBack)
+    },
+    goForward: () => {
+        electron.ipcRenderer.send(ipc.Channel.goForward)
+    },
+})
+
 electron.ipcRenderer.on(
     ipc.Channel.importProjectFromPath,
     (_event, projectPath: string, projectId: string) => {

app/ide-desktop/lib/dashboard/src/App.tsx

@@ -140,7 +140,7 @@ export interface AppProps {
 export default function App(props: AppProps) {
   // This is a React component even though it does not contain JSX.
   // eslint-disable-next-line no-restricted-syntax
-  const Router = detect.isOnElectron() ? router.MemoryRouter : router.BrowserRouter
+  const Router = detect.isOnElectron() ? router.HashRouter : router.BrowserRouter
   // Both `BackendProvider` and `InputBindingsProvider` depend on `LocalStorageProvider`.
   // Note that the `Router` must be the parent of the `AuthProvider`, because the `AuthProvider`
   // will redirect the user between the login/register pages and the dashboard.
@@ -186,6 +186,7 @@ function AppRouter(props: AppProps) {
     window.navigate = navigate
   }
   const [inputBindingsRaw] = React.useState(() => inputBindingsModule.createBindings())
+
   React.useEffect(() => {
     const savedInputBindings = localStorage.get('inputBindings')
     if (savedInputBindings != null) {
@@ -203,6 +204,7 @@ function AppRouter(props: AppProps) {
       }
     }
   }, [/* should never change */ localStorage, /* should never change */ inputBindingsRaw])
+
   const inputBindings = React.useMemo(() => {
     const updateLocalStorage = () => {
       localStorage.set(
@@ -250,11 +252,14 @@ function AppRouter(props: AppProps) {
       },
     }
   }, [/* should never change */ localStorage, /* should never change */ inputBindingsRaw])
+
   const mainPageUrl = getMainPageUrl()
+
   const authService = React.useMemo(() => {
     const authConfig = { navigate, ...props }
     return authServiceModule.initAuthService(authConfig)
   }, [props, /* should never change */ navigate])
+
   const userSession = authService?.cognito.userSession.bind(authService.cognito) ?? null
   const registerAuthEventListener = authService?.registerAuthEventListener ?? null
   const initialBackend: Backend = isAuthenticationDisabled
@@ -262,6 +267,7 @@ function AppRouter(props: AppProps) {
     : // This is safe, because the backend is always set by the authentication flow.
       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
       null!
+
   React.useEffect(() => {
     let isClick = false
     const onMouseDown = () => {
@@ -283,6 +289,7 @@ function AppRouter(props: AppProps) {
         }
       }
     }
+
     const onSelectStart = () => {
       isClick = false
     }
@@ -295,6 +302,7 @@ function AppRouter(props: AppProps) {
       document.removeEventListener('selectstart', onSelectStart)
     }
   }, [])
+
   const routes = (
     <router.Routes>
       <React.Fragment>

app/ide-desktop/lib/dashboard/src/components/EditableSpan.tsx

@@ -4,6 +4,8 @@ import * as React from 'react'
 import CrossIcon from 'enso-assets/cross.svg'
 import TickIcon from 'enso-assets/tick.svg'
 
+import * as eventCalback from '#/hooks/eventCallbackHooks'
+
 import * as inputBindingsProvider from '#/providers/InputBindingsProvider'
 
 import SvgMask from '#/components/SvgMask'
@@ -38,6 +40,10 @@ export default function EditableSpan(props: EditableSpanProps) {
   const inputRef = React.useRef<HTMLInputElement>(null)
   const cancelled = React.useRef(false)
 
+  // Making sure that the event callback is stable.
+  // to prevent the effect from re-running.
+  const onCancelEventCallback = eventCalback.useEventCallback(onCancel)
+
   React.useEffect(() => {
     setIsSubmittable(checkSubmittable?.(inputRef.current?.value ?? '') ?? true)
     // This effect MUST only run on mount.
@@ -48,7 +54,7 @@ export default function EditableSpan(props: EditableSpanProps) {
     if (editable) {
       return inputBindings.attach(sanitizedEventTargets.document.body, 'keydown', {
         cancelEditName: () => {
-          onCancel()
+          onCancelEventCallback()
           cancelled.current = true
           inputRef.current?.blur()
         },
@@ -56,7 +62,7 @@ export default function EditableSpan(props: EditableSpanProps) {
     } else {
       return
     }
-  }, [editable, onCancel, /* should never change */ inputBindings])
+  }, [editable, /* should never change */ inputBindings, onCancelEventCallback])
 
   React.useEffect(() => {
     cancelled.current = false

app/ide-desktop/lib/dashboard/src/components/SvgMask.tsx

@@ -35,20 +35,24 @@ export default function SvgMask(props: SvgMaskProps) {
         ...(style ?? {}),
         backgroundColor: color ?? 'currentcolor',
         mask: urlSrc,
+        maskPosition: 'center',
+        maskRepeat: 'no-repeat',
+        maskSize: 'contain',
         // The names come from a third-party API and cannot be changed.
-        // eslint-disable-next-line @typescript-eslint/naming-convention
+        /* eslint-disable @typescript-eslint/naming-convention */
         WebkitMask: urlSrc,
+        WebkitMaskPosition: 'center',
+        WebkitMaskRepeat: 'no-repeat',
+        WebkitMaskSize: 'contain',
+        /* eslint-enable @typescript-eslint/naming-convention */
       }}
       className={`inline-block ${onClick != null ? 'cursor-pointer' : ''} ${
         className ?? 'h-max w-max'
       }`}
       onClick={onClick}
-      onDragStart={event => {
-        event.preventDefault()
-      }}
     >
       {/* This is required for this component to have the right size. */}
-      <img alt={alt} src={src} className="transparent" />
+      <img alt={alt} src={src} className="transparent" draggable={false} />
     </div>
   )
 }

app/ide-desktop/lib/dashboard/src/configurations/inputBindings.ts

@@ -5,6 +5,8 @@ import AddFolderIcon from 'enso-assets/add_folder.svg'
 import AddKeyIcon from 'enso-assets/add_key.svg'
 import AddNetworkIcon from 'enso-assets/add_network.svg'
 import AppDownloadIcon from 'enso-assets/app_download.svg'
+import ArrowLeftIcon from 'enso-assets/arrow_left.svg'
+import ArrowRightIcon from 'enso-assets/arrow_right.svg'
 import CameraIcon from 'enso-assets/camera.svg'
 import CloseIcon from 'enso-assets/close.svg'
 import CloudToIcon from 'enso-assets/cloud_to.svg'
@@ -101,4 +103,16 @@ export const BINDINGS = inputBindings.defineBindings({
     bindings: ['Mod+Shift+PointerMain'],
     rebindable: false,
   },
+  goBack: {
+    name: 'Go Back',
+    bindings: detect.isOnMacOS() ? ['Mod+ArrowLeft', 'Mod+['] : ['Alt+ArrowLeft'],
+    rebindable: true,
+    icon: ArrowLeftIcon,
+  },
+  goForward: {
+    name: 'Go Forward',
+    bindings: detect.isOnMacOS() ? ['Mod+ArrowRight', 'Mod+]'] : ['Alt+ArrowRight'],
+    rebindable: true,
+    icon: ArrowRightIcon,
+  },
 })

app/ide-desktop/lib/dashboard/src/hooks/eventCallbackHooks.ts

@@ -0,0 +1,23 @@
+/**
+ * @file useEventCallback shim
+ */
+
+import * as React from 'react'
+
+import * as syncRef from '#/hooks/syncRefHooks'
+
+/**
+ * useEvent shim.
+ * @see https://github.com/reactjs/rfcs/pull/220
+ * @see https://github.com/reactjs/rfcs/blob/useevent/text/0000-useevent.md#internal-implementation
+ */
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export function useEventCallback<Func extends (...args: any[]) => unknown>(callback: Func) {
+  const callbackRef = syncRef.useSyncRef(callback)
+
+  // Make sure that the value of `this` provided for the call to fn is not `ref`
+  // This type assertion is safe, because it's a transparent wrapper around the original callback
+  // we mute react-hooks/exhaustive-deps because we don't need to update the callback when the callbackRef changes(it never does)
+  // eslint-disable-next-line react-hooks/exhaustive-deps, no-restricted-syntax
+  return React.useCallback(((...args) => callbackRef.current.apply(void 0, args)) as Func, [])
+}

app/ide-desktop/lib/dashboard/src/hooks/searchParamsStateHooks.ts

@@ -0,0 +1,80 @@
+/**
+ * @file
+ *
+ * Search params state hook store a value in the URL search params.
+ */
+import * as React from 'react'
+
+import * as reactRouterDom from 'react-router-dom'
+
+import * as eventCallback from '#/hooks/eventCallbackHooks'
+import * as lazyMemo from '#/hooks/useLazyMemoHooks'
+
+import * as safeJsonParse from '#/utilities/safeJsonParse'
+
+/**
+ * The return type of the `useSearchParamsState` hook.
+ */
+type SearchParamsStateReturnType<T> = Readonly<
+  [value: T, setValue: (nextValue: React.SetStateAction<T>) => void, clear: () => void]
+>
+
+/**
+ * Hook that synchronize a state in the URL search params. It returns the value, a setter and a clear function.
+ * @param key - The key to store the value in the URL search params.
+ * @param defaultValue - The default value to use if the key is not present in the URL search params.
+ * @param predicate - A function to check if the value is of the right type.
+ */
+export function useSearchParamsState<T = unknown>(
+  key: string,
+  defaultValue: T | (() => T),
+  predicate: (unknown: unknown) => unknown is T = (unknown): unknown is T => true
+): SearchParamsStateReturnType<T> {
+  const [searchParams, setSearchParams] = reactRouterDom.useSearchParams()
+
+  const lazyDefaultValueInitializer = lazyMemo.useLazyMemoHooks(defaultValue, [])
+  const predicateEventCallback = eventCallback.useEventCallback(predicate)
+
+  const clear = eventCallback.useEventCallback((replace: boolean = false) => {
+    searchParams.delete(key)
+    setSearchParams(searchParams, { replace })
+  })
+
+  const rawValue = React.useMemo<T>(() => {
+    const maybeValue = searchParams.get(key)
+    const defaultValueFrom = lazyDefaultValueInitializer()
+
+    return maybeValue != null
+      ? safeJsonParse.safeJsonParse(maybeValue, defaultValueFrom, (unknown): unknown is T => true)
+      : defaultValueFrom
+  }, [key, lazyDefaultValueInitializer, searchParams])
+
+  const isValueValid = predicateEventCallback(rawValue)
+
+  const value = isValueValid ? rawValue : lazyDefaultValueInitializer()
+
+  if (!isValueValid) {
+    clear(true)
+  }
+
+  /**
+   * Set the value in the URL search params. If the next value is the same as the default value, it will remove the key from the URL search params.
+   * Function reference is always the same.
+   * @param nextValue - The next value to set.
+   * @returns void
+   */
+  const setValue = eventCallback.useEventCallback((nextValue: React.SetStateAction<T>) => {
+    if (nextValue instanceof Function) {
+      nextValue = nextValue(value)
+    }
+
+    if (nextValue === lazyDefaultValueInitializer()) {
+      clear()
+    } else {
+      searchParams.set(key, JSON.stringify(nextValue))
+      setSearchParams(searchParams)
+    }
+  })
+
+  return [value, setValue, clear]
+}

app/ide-desktop/lib/dashboard/src/hooks/syncRefHooks.ts

@@ -0,0 +1,17 @@
+/**
+ * @file useSyncRef.ts
+ *
+ * A hook that returns a ref object whose `current` property is always in sync with the provided value.
+ */
+
+import * as React from 'react'
+
+/**
+ * A hook that returns a ref object whose `current` property is always in sync with the provided value.
+ */
+export function useSyncRef<T>(value: T): React.MutableRefObject<T> {
+  const ref = React.useRef(value)
+  ref.current = value
+
+  return ref
+}

app/ide-desktop/lib/dashboard/src/hooks/useLazyMemoHooks.ts

@@ -0,0 +1,29 @@
+/**
+ * @file
+ *
+ * A hook that returns a memoized function that will only be called once
+ */
+
+import * as React from 'react'
+
+const UNSET_VALUE = Symbol('unset')
+
+/**
+ * A hook that returns a memoized function that will only be called once
+ */
+export function useLazyMemoHooks<T>(factory: T | (() => T), deps: React.DependencyList): () => T {
+  return React.useMemo(() => {
+    let cachedValue: T | typeof UNSET_VALUE = UNSET_VALUE
+
+    return (): T => {
+      if (cachedValue === UNSET_VALUE) {
+        cachedValue = factory instanceof Function ? factory() : factory
+      }
+
+      return cachedValue
+    }
+    // We assume that the callback should change only when
+    // the deps change.
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, deps)
+}

app/ide-desktop/lib/dashboard/src/layouts/CategorySwitcher.tsx

@@ -5,7 +5,6 @@ import Home2Icon from 'enso-assets/home2.svg'
 import RecentIcon from 'enso-assets/recent.svg'
 import Trash2Icon from 'enso-assets/trash2.svg'
 
-import * as localStorageProvider from '#/providers/LocalStorageProvider'
 import * as modalProvider from '#/providers/ModalProvider'
 
 import type * as assetEvent from '#/events/assetEvent'
@@ -46,6 +45,7 @@ interface InternalCategorySwitcherItemProps {
 function CategorySwitcherItem(props: InternalCategorySwitcherItemProps) {
   const { category, isCurrent, onClick } = props
   const { onDragOver, onDrop } = props
+
   return (
     <button
       disabled={isCurrent}
@@ -89,11 +89,6 @@ export interface CategorySwitcherProps {
 export default function CategorySwitcher(props: CategorySwitcherProps) {
   const { category, setCategory, dispatchAssetEvent } = props
   const { unsetModal } = modalProvider.useSetModal()
-  const { localStorage } = localStorageProvider.useLocalStorage()
-
-  React.useEffect(() => {
-    localStorage.set('driveCategory', category)
-  }, [category, /* should never change */ localStorage])
 
   return (
     <div className="flex w-full flex-col gap-sidebar-section-heading">

app/ide-desktop/lib/dashboard/src/layouts/Drive.tsx

@@ -5,7 +5,9 @@ import * as common from 'enso-common'
 
 import * as appUtils from '#/appUtils'
 
+import * as eventCallback from '#/hooks/eventCallbackHooks'
 import * as navigateHooks from '#/hooks/navigateHooks'
+import * as searchParamsState from '#/hooks/searchParamsStateHooks'
 import * as toastAndLogHooks from '#/hooks/toastAndLogHooks'
 
 import * as authProvider from '#/providers/AuthProvider'
@@ -120,8 +122,10 @@ export default function Drive(props: DriveProps) {
   const { localStorage } = localStorageProvider.useLocalStorage()
   const [canDownload, setCanDownload] = React.useState(false)
   const [didLoadingProjectManagerFail, setDidLoadingProjectManagerFail] = React.useState(false)
-  const [category, setCategory] = React.useState(
+  const [category, setCategory] = searchParamsState.useSearchParamsState(
-    () => localStorage.get('driveCategory') ?? Category.home
+    'driveCategory',
+    () => localStorage.get('driveCategory') ?? Category.home,
+    (value): value is Category => array.includes(Object.values(Category), value)
   )
   const [newLabelNames, setNewLabelNames] = React.useState(new Set<backendModule.LabelName>())
   const [deletedLabelNames, setDeletedLabelNames] = React.useState(
@@ -145,6 +149,11 @@ export default function Drive(props: DriveProps) {
           ? DriveStatus.notEnabled
           : DriveStatus.ok
 
+  const onSetCategory = eventCallback.useEventCallback((value: Category) => {
+    setCategory(value)
+    localStorage.set('driveCategory', value)
+  })
+
   React.useEffect(() => {
     const onProjectManagerLoadingFailed = () => {
       setDidLoadingProjectManagerFail(true)
@@ -379,7 +388,7 @@ export default function Drive(props: DriveProps) {
               <div className="flex w-drive-sidebar flex-col gap-drive-sidebar py-drive-sidebar-y">
                 <CategorySwitcher
                   category={category}
-                  setCategory={setCategory}
+                  setCategory={onSetCategory}
                   dispatchAssetEvent={dispatchAssetEvent}
                 />
                 <Labels

app/ide-desktop/lib/dashboard/src/layouts/Settings.tsx

@@ -1,6 +1,8 @@
 /** @file Settings screen. */
 import * as React from 'react'
 
+import * as searchParamsState from '#/hooks/searchParamsStateHooks'
+
 import * as authProvider from '#/providers/AuthProvider'
 import * as backendProvider from '#/providers/BackendProvider'
 
@@ -14,13 +16,19 @@ import SettingsSidebar from '#/layouts/SettingsSidebar'
 
 import * as backendModule from '#/services/Backend'
 
+import * as array from '#/utilities/array'
+
 // ================
 // === Settings ===
 // ================
 
 /** Settings screen. */
 export default function Settings() {
-  const [settingsTab, setSettingsTab] = React.useState(SettingsTab.account)
+  const [settingsTab, setSettingsTab] = searchParamsState.useSearchParamsState(
+    'SettingsTab',
+    SettingsTab.account,
+    (value): value is SettingsTab => array.includes(Object.values(SettingsTab), value)
+  )
   const { type: sessionType, user } = authProvider.useNonPartialUserSession()
   const { backend } = backendProvider.useBackend()
   const [organization, setOrganization] = React.useState<backendModule.OrganizationInfo>(() => ({

app/ide-desktop/lib/dashboard/src/pages/dashboard/Dashboard.tsx

@@ -2,7 +2,10 @@
  * interactive components. */
 import * as React from 'react'
 
+import * as detect from 'enso-common/src/detect'
+
 import * as eventHooks from '#/hooks/eventHooks'
+import * as searchParamsState from '#/hooks/searchParamsStateHooks'
 
 import * as authProvider from '#/providers/AuthProvider'
 import * as backendProvider from '#/providers/BackendProvider'
@@ -122,7 +125,14 @@ export default function Dashboard(props: DashboardProps) {
   const inputBindings = inputBindingsProvider.useInputBindings()
   const [initialized, setInitialized] = React.useState(false)
   const [isHelpChatOpen, setIsHelpChatOpen] = React.useState(false)
-  const [page, setPage] = React.useState(() => localStorage.get('page') ?? pageSwitcher.Page.drive)
+
+  // These pages MUST be ROUTER PAGES.
+  const [page, setPage] = searchParamsState.useSearchParamsState(
+    'page',
+    () => localStorage.get('page') ?? pageSwitcher.Page.drive,
+    (value: unknown): value is pageSwitcher.Page =>
+      array.includes(Object.values(pageSwitcher.Page), value)
+  )
   const [queuedAssetEvents, setQueuedAssetEvents] = React.useState<assetEvent.AssetEvent[]>([])
   const [query, setQuery] = React.useState(() => AssetQuery.fromString(''))
   const [labels, setLabels] = React.useState<backendModule.Label[]>([])
@@ -163,7 +173,7 @@ export default function Dashboard(props: DashboardProps) {
     if (query.query !== '') {
       setPage(pageSwitcher.Page.drive)
     }
-  }, [query])
+  }, [query, setPage])
 
   React.useEffect(() => {
     let currentBackend = backend
@@ -327,14 +337,24 @@ export default function Dashboard(props: DashboardProps) {
           }
         },
       }),
-    [
+    [inputBindings, modalRef, localStorage, updateModal, setPage]
-      inputBindings,
-      /* should never change */ modalRef,
-      /* should never change */ localStorage,
-      /* should never change */ updateModal,
-    ]
   )
 
+  React.useEffect(() => {
+    if (detect.isOnElectron()) {
+      // We want to handle the back and forward buttons in electron the same way as in the browser.
+      // eslint-disable-next-line no-restricted-syntax
+      return inputBindings.attach(sanitizedEventTargets.document.body, 'keydown', {
+        goBack: () => {
+          window.navigationApi.goBack()
+        },
+        goForward: () => {
+          window.navigationApi.goForward()
+        },
+      })
+    }
+  }, [inputBindings])
+
   const setBackendType = React.useCallback(
     (newBackendType: backendModule.BackendType) => {
       if (newBackendType !== backend.type) {
@@ -398,7 +418,7 @@ export default function Dashboard(props: DashboardProps) {
         })
       }
     },
-    [backend, projectStartupInfo?.project.projectId, session.accessToken]
+    [backend, projectStartupInfo?.project.projectId, session.accessToken, setPage]
   )
 
   const doCloseEditor = React.useCallback((closingProject: backendModule.ProjectAsset) => {
@@ -420,7 +440,7 @@ export default function Dashboard(props: DashboardProps) {
       setPage(pageSwitcher.Page.drive)
     }
     setProjectStartupInfo(null)
-  }, [page])
+  }, [page, setPage])
 
   return (
     <>

app/ide-desktop/lib/dashboard/src/providers/LocalStorageProvider.tsx

@@ -27,7 +27,7 @@ export interface LocalStorageProviderProps extends Readonly<React.PropsWithChild
 /** A React Provider that lets components get the shortcut registry. */
 export default function LocalStorageProvider(props: LocalStorageProviderProps) {
   const { children } = props
-  const [localStorage] = React.useState(() => new LocalStorage())
+  const localStorage = React.useMemo(() => new LocalStorage(), [])
 
   return (
     <LocalStorageContext.Provider value={{ localStorage }}>{children}</LocalStorageContext.Provider>

app/ide-desktop/lib/dashboard/src/utilities/safeJsonParse.ts

@@ -0,0 +1,25 @@
+/**
+ * @file
+ *
+ * A utility function to safely parse a JSON string.
+ * returns the default value if the JSON string is invalid.
+ * Also provides a type for the parsed JSON.
+ */
+
+/**
+ * Safely parse a JSON string.
+ * Parse the JSON string and return the default value if the JSON string is invalid.
+ * Or if the parsed JSON does not match the type assertion.
+ */
+export function safeJsonParse<T = unknown>(
+  value: string,
+  defaultValue: T,
+  predicate: (parsed: unknown) => parsed is T
+): T {
+  try {
+    const parsed: unknown = JSON.parse(value)
+    return predicate(parsed) ? parsed : defaultValue
+  } catch {
+    return defaultValue
+  }
+}

app/ide-desktop/lib/types/globals.d.ts

@@ -55,6 +55,19 @@ interface AuthenticationApi {
     readonly saveAccessToken: (accessToken: SaveAccessTokenPayload | null) => void
 }
 
+// ======================
+// === Navigation API ===
+// ======================
+
+/** `window.navigationApi` is a context bridge to the main process, when we're running in an
+ * Electron context. It contains navigation-related functionality. */
+interface NavigationApi {
+    /** Go back in the navigation history. */
+    readonly goBack: () => void
+    /** Go forward in the navigation history. */
+    readonly goForward: () => void
+}
+
 // =====================================
 // === Global namespace augmentation ===
 // =====================================
@@ -67,6 +80,7 @@ declare global {
         readonly enso?: AppRunner & Enso
         readonly backendApi?: BackendApi
         readonly authenticationApi: AuthenticationApi
+        readonly navigationApi: NavigationApi
     }
 
     namespace NodeJS {