electron/spec/api-ipc-renderer-spec.ts

import { expect } from 'chai';
import * as path from 'node:path';
import { ipcMain, BrowserWindow, WebContents, WebPreferences, webContents } from 'electron/main';
import { closeWindow } from './lib/window-helpers';
import { once } from 'node:events';

describe('ipcRenderer module', () => {
  const fixtures = path.join(__dirname, 'fixtures');

  let w: BrowserWindow;
  before(async () => {
    w = new BrowserWindow({ show: false, webPreferences: { nodeIntegration: true, contextIsolation: false } });
    await w.loadURL('about:blank');
  });
  after(async () => {
    await closeWindow(w);
    w = null as unknown as BrowserWindow;
  });

  describe('send()', () => {
    it('should work when sending an object containing id property', async () => {
      const obj = {
        id: 1,
        name: 'ly'
      };
      w.webContents.executeJavaScript(`{
        const { ipcRenderer } = require('electron')
        ipcRenderer.send('message', ${JSON.stringify(obj)})
      }`);
      const [, received] = await once(ipcMain, 'message');
      expect(received).to.deep.equal(obj);
    });

    it('can send instances of Date as Dates', async () => {
      const isoDate = new Date().toISOString();
      w.webContents.executeJavaScript(`{
        const { ipcRenderer } = require('electron')
        ipcRenderer.send('message', new Date(${JSON.stringify(isoDate)}))
      }`);
      const [, received] = await once(ipcMain, 'message');
      expect(received.toISOString()).to.equal(isoDate);
    });

    it('can send instances of Buffer', async () => {
      const data = 'hello';
      w.webContents.executeJavaScript(`{
        const { ipcRenderer } = require('electron')
        ipcRenderer.send('message', Buffer.from(${JSON.stringify(data)}))
      }`);
      const [, received] = await once(ipcMain, 'message');
      expect(received).to.be.an.instanceOf(Uint8Array);
      expect(Buffer.from(data).equals(received)).to.be.true();
    });

    it('throws when sending objects with DOM class prototypes', async () => {
      await expect(w.webContents.executeJavaScript(`{
        const { ipcRenderer } = require('electron')
        ipcRenderer.send('message', document.location)
      }`)).to.eventually.be.rejected();
    });

    it('does not crash when sending external objects', async () => {
      await expect(w.webContents.executeJavaScript(`{
        const { ipcRenderer } = require('electron')
        const http = require('node:http')

        const request = http.request({ port: 5000, hostname: '127.0.0.1', method: 'GET', path: '/' })
        const stream = request.agent.sockets['127.0.0.1:5000:'][0]._handle._externalStream

        ipcRenderer.send('message', stream)
      }`)).to.eventually.be.rejected();
    });

    it('can send objects that both reference the same object', async () => {
      w.webContents.executeJavaScript(`{
        const { ipcRenderer } = require('electron')

        const child = { hello: 'world' }
        const foo = { name: 'foo', child: child }
        const bar = { name: 'bar', child: child }
        const array = [foo, bar]

        ipcRenderer.send('message', array, foo, bar, child)
      }`);

      const child = { hello: 'world' };
      const foo = { name: 'foo', child: child };
      const bar = { name: 'bar', child: child };
      const array = [foo, bar];

      const [, arrayValue, fooValue, barValue, childValue] = await once(ipcMain, 'message');
      expect(arrayValue).to.deep.equal(array);
      expect(fooValue).to.deep.equal(foo);
      expect(barValue).to.deep.equal(bar);
      expect(childValue).to.deep.equal(child);
    });

    it('can handle cyclic references', async () => {
      w.webContents.executeJavaScript(`{
        const { ipcRenderer } = require('electron')
        const array = [5]
        array.push(array)

        const child = { hello: 'world' }
        child.child = child
        ipcRenderer.send('message', array, child)
      }`);

      const [, arrayValue, childValue] = await once(ipcMain, 'message');
      expect(arrayValue[0]).to.equal(5);
      expect(arrayValue[1]).to.equal(arrayValue);

      expect(childValue.hello).to.equal('world');
      expect(childValue.child).to.equal(childValue);
    });
  });

  describe('sendSync()', () => {
    it('can be replied to by setting event.returnValue', async () => {
      ipcMain.once('echo', (event, msg) => {
        event.returnValue = msg;
      });
      const msg = await w.webContents.executeJavaScript(`new Promise(resolve => {
        const { ipcRenderer } = require('electron')
        resolve(ipcRenderer.sendSync('echo', 'test'))
      })`);
      expect(msg).to.equal('test');
    });
  });

  describe('sendTo()', () => {
    const generateSpecs = (description: string, webPreferences: WebPreferences) => {
      describe(description, () => {
        let contents: WebContents;
        const payload = 'Hello World!';

        before(async () => {
          contents = (webContents as typeof ElectronInternal.WebContents).create({
            preload: path.join(fixtures, 'module', 'preload-ipc-ping-pong.js'),
            ...webPreferences
          });

          await contents.loadURL('about:blank');
        });

        after(() => {
          contents.destroy();
          contents = null as unknown as WebContents;
        });

        it('sends message to WebContents', async () => {
          const data = await w.webContents.executeJavaScript(`new Promise(resolve => {
            const { ipcRenderer } = require('electron')
            ipcRenderer.sendTo(${contents.id}, 'ping', ${JSON.stringify(payload)})
            ipcRenderer.once('pong', (event, data) => resolve(data))
          })`);
          expect(data).to.equal(payload);
        });

        it('sends message on channel with non-ASCII characters to WebContents', async () => {
          const data = await w.webContents.executeJavaScript(`new Promise(resolve => {
            const { ipcRenderer } = require('electron')
            ipcRenderer.sendTo(${contents.id}, 'ping-æøåü', ${JSON.stringify(payload)})
            ipcRenderer.once('pong-æøåü', (event, data) => resolve(data))
          })`);
          expect(data).to.equal(payload);
        });
      });
    };

    generateSpecs('without sandbox', {});
    generateSpecs('with sandbox', { sandbox: true });
    generateSpecs('with contextIsolation', { contextIsolation: true });
    generateSpecs('with contextIsolation + sandbox', { contextIsolation: true, sandbox: true });
  });

  describe('ipcRenderer.on', () => {
    it('is not used for internals', async () => {
      const result = await w.webContents.executeJavaScript(`
        require('electron').ipcRenderer.eventNames()
      `);
      expect(result).to.deep.equal([]);
    });
  });

  describe('after context is released', () => {
    it('throws an exception', async () => {
      const error = await w.webContents.executeJavaScript(`(${() => {
        const child = window.open('', 'child', 'show=no,nodeIntegration=yes')! as any;
        const childIpc = child.require('electron').ipcRenderer;
        child.close();
        return new Promise(resolve => {
          setInterval(() => {
            try {
              childIpc.send('hello');
            } catch (e) {
              resolve(e);
            }
          }, 16);
        });
      }})()`);
      expect(error).to.have.property('message', 'IPC method called after context was released');
    });
  });
});