Add SessionManager class

Has the following benefits:
* `ses.protocol.handle` only once per Tab
* Session data is cleared after tab is destroyed
* File requests no longer have to redirect

src/main/SessionManager.ts

@@ -0,0 +1,69 @@
+import { session, Session } from 'electron';
+import { fileURLToPath } from 'url';
+import fs from 'fs/promises';
+import convertText from './convertText';
+import { getFileType } from '../utils/fileTypes';
+
+export default class SessionManager {
+    sessions: Record<string, { file: string, mode: string, text: string, ses: Session }> = {};
+
+    private textResponse(mode: string, text: string) {
+        return new Response(convertText(mode, text), {
+            headers: { 'content-type': 'text/html' }
+        });
+    }
+
+    private configureIntercept(partition: string, ses: Session) {
+        ses.protocol.handle('file', async (req) => {
+            const { file, mode, text } = this.sessions[partition];
+
+            let requestFile: string | undefined;
+
+            try {
+                requestFile = fileURLToPath(req.url);
+            } catch (_) {
+                // Not a valid file
+            }
+
+            // Intercept the file being edited
+            if (req.url === `file://${partition}/` || (requestFile !== undefined && requestFile === file))
+                return this.textResponse(mode, text);
+
+            // Convert supported file types
+            if (requestFile !== undefined && getFileType(requestFile)) {
+                return this.textResponse(mode,  await fs.readFile(requestFile, 'utf8'));
+            }
+
+            // @ts-ignore bypassCustomProtocolHandlers is allowed
+            return ses.fetch(req, { bypassCustomProtocolHandlers: true })
+        });
+    }
+
+    private start(partition: string, file: string, mode: string, text: string) {
+        const ses = session.fromPartition(partition);
+
+        this.sessions[partition] = { file, mode, text, ses };
+        this.configureIntercept(partition, ses);
+    }
+
+    private update(partition: string, file: string, mode: string, text: string) {
+        this.sessions[partition].file = file;
+        this.sessions[partition].mode = mode;
+        this.sessions[partition].text = text;
+    }
+
+    set(partition: string, file: string, mode: string, text: string) {
+        if (!(partition in this.sessions)) {
+            this.start(partition, file, mode, text);
+            return;
+        }
+
+        this.update(partition, file, mode, text);
+    }
+
+    delete(partition: string) {
+        this.sessions[partition]?.ses.clearStorageData();
+
+        delete this.sessions[partition];
+    }
+}

src/main/main.ts

@@ -2,7 +2,7 @@ import { app, BrowserWindow, ipcMain, webContents, dialog, nativeTheme, Menu } f
 import { getOpenFilters, getSaveFilters } from '../utils/fileTypes';
 import { showContextMenu } from './contextMenu';
 import { join } from 'path';
-import interceptFileProtocol from './interceptFileProtocol';
+import SessionManager from './SessionManager';
 import showTopMenu from './showTopMenu';
 import { randomUUID } from 'crypto';
 import handleKeyboardShortcut from './handleKeyboardShortcut';
@@ -27,7 +27,8 @@ const store = new Store(),
 	settings = new SettingStore(emitSettingsUpdate, store),
 	fileHandler = new FileHandler(),
 	windowFactory = new WindowFactory(store, fileHandler),
-	updater = new Updater();
+	updater = new Updater(),
+	sessionManager = new SessionManager();
 
 Menu.setApplicationMenu(Menu.buildFromTemplate([]));
 fileHandler.registerEvents(app);
@@ -125,7 +126,9 @@ settings.callAndListen('theme', (theme: 'system' | 'light' | 'dark') => {
 	nativeTheme.themeSource = theme;
 });
 
-ipcMain.on('intercept-file', interceptFileProtocol);
+ipcMain.on('set-session',(_, ...args: [string, string, string, string]) => sessionManager.set(...args));
+ipcMain.on('delete-session', (_, partition: string) => sessionManager.delete(partition));
+
 ipcMain.on('show-menu', showTopMenu);
 ipcMain.on('keyboard-input', handleKeyboardShortcut);
 

src/window/Tab.ts

@@ -216,7 +216,7 @@ export default class Tab {
 
 		await this.webviewReady;
 
-		ipcRenderer.send('intercept-file', this.partition, this.path, this.mode, value);
+		ipcRenderer.send('set-session', this.partition, this.path, this.mode, value);
 
 		try {
 			await this.webview.loadURL(this.path ? pathToFileURL(this.path).href : `file://${this.partition}/`);
@@ -377,6 +377,7 @@ export default class Tab {
 		this.webviewSubContainer.remove();
 		this.devtools.remove();
 		this.removeCSSUpdateListener?.();
+		ipcRenderer.send('delete-session', this.partition);
 	}
 
 	getTabData(): TabData {