Remove legacy data

src-main/l10n/en.json

@@ -283,6 +283,10 @@
     "string": "Finalizing...",
     "developer_comment": "Status message that appears while finishing an update."
   },
+  "migrate.delete-legacy": {
+    "string": "Deleting old data...",
+    "developer_comment": "Status message that appears while finishing an update. Old data refers to copies of data used by old versions of the app that are no longer needed."
+  },
   "update.window-title": {
     "string": "Update Available",
     "developer_comment": "Title of update available window"

src-main/migrate.js

@@ -4,11 +4,13 @@ const path = require('path');
 const settings = require('./settings');
 const MigrateWindow = require('./windows/migrate');
 
-// This needs to run before the app is ready
-const userData = app.getPath('userData');
+// Avoid running migrate logic on fresh installs when we can. Not required, just helps
+// user experience. This must run before the ready event.
 const isFirstLaunch = (
   settings.dataVersion !== MigrateWindow.LATEST_VERSION &&
-  !fs.existsSync(path.join(userData, 'Cache'))
+  // Electron will always create the Cache directory in userData after the ready event,
+  // so if it doesn't exist yet, this is probably a fresh install.
+  !fs.existsSync(path.join(app.getPath('userData'), 'Cache'))
 );
 
 const migrate = async () => {

src-main/windows/migrate.js

@@ -8,19 +8,22 @@ const {APP_NAME} = require('../brand');
 const EMAIL = '[email protected]';
 
 class MigrateWindow extends BaseWindow {
-  static LATEST_VERSION = 2;
+  static LATEST_VERSION = 3;
 
   constructor () {
     super();
 
+    const oldDataVersion = settings.dataVersion;
+
     this.promise = new Promise((resolve) => {
       this.resolveCallback = resolve;
     });
 
     const ipc = this.window.webContents.ipc;
 
-    ipc.on('get-strings', (event) => {
+    ipc.on('get-info', (event) => {
       event.returnValue = {
+        oldDataVersion,
         locale: getLocale(),
         strings: getStrings()
       };

src-preload/migrate.js

@@ -1,7 +1,7 @@
 const {contextBridge, ipcRenderer} = require('electron');
 
 contextBridge.exposeInMainWorld('MigratePreload', {
-  getStrings: () => ipcRenderer.sendSync('get-strings'),
+  getInfo: () => ipcRenderer.sendSync('get-info'),
   done: () => ipcRenderer.invoke('done'),
   continueAnyways: () => ipcRenderer.invoke('continue-anyways')
 });

src-renderer/migrate/migrate.html

@@ -152,7 +152,7 @@ <h1 class="title"></h1>
       TW_AutoSave -> abandon (likely to be very large)
       */
 
-      const {strings, locale} = MigratePreload.getStrings();
+      const {oldDataVersion, strings, locale} = MigratePreload.getInfo();
       document.documentElement.lang = locale;
 
       document.querySelector('.title').textContent = strings['migrate.title'];
@@ -354,6 +354,38 @@ <h1 class="title"></h1>
         });
       };
 
+      const deleteDatabase = (databaseName) => new Promise((resolve, reject) => {
+        const request = indexedDB.deleteDatabase(databaseName);
+        request.onerror = () => {
+          reject(new Error(`Failed to delete IDB database ${databaseName}: ${request.error}`));
+        };
+        request.onsuccess = () => {
+          resolve();
+        };
+      });
+
+      const deleteLegacyData = async () => {
+        // Give the browser some time to clean up; deleting large databases might be intensive
+        const sleep = () => new Promise((resolve) => setTimeout(resolve, 250));
+
+        // 1 for local storages + 1 for each IDB
+        const totalOperations = 1 + databases.length;
+        setStepProgress(0, totalOperations);
+
+        localStorage.clear();
+        sessionStorage.clear();
+
+        await sleep();
+        setStepProgress(1, totalOperations);
+
+        for (let i = 0; i < databases.length; i++) {
+          await deleteDatabase(databases[i].name);
+          await sleep();
+          // 1 for local storage + 1 for the DB we just deleted (i starts from 0)
+          setStepProgress(2 + i, totalOperations);
+        }
+      };
+
       const finish = async () => {
         await MigratePreload.done();
       };
@@ -417,13 +449,18 @@ <h1 class="title"></h1>
 
         await runStep(strings['migrate.preparing'], gatherMetadata);
 
-        if (!anyError) {
-          // Preparing must succeed for both of these, but each of these can fail
-          // independently.
+        if (!anyError && oldDataVersion < 2) {
+          // V2: Migrate data from file:// to tw-*://
+          // Preparing must succeed for both of these, but each can fail independently.
           await runStep(strings['migrate.transfer-editor'], migrateEditor);
           await runStep(strings['migrate.transfer-packager'], migratePackager);
         }
 
+        if (!anyError && oldDataVersion < 3) {
+          // V3: Removing leftover data on file://
+          await runStep(strings['migrate.delete-legacy'], deleteLegacyData);
+        }
+
         if (!anyError) {
           await runStep(strings['migrate.finalizing'], finish);
         }