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

import { expect } from 'chai';
import { BrowserWindow, ipcMain, IpcMainInvokeEvent } from 'electron';

describe('ipc module', () => {
  describe('invoke', () => {
    let w = (null as unknown as BrowserWindow);

    before(async () => {
      w = new BrowserWindow({ show: false, webPreferences: { nodeIntegration: true } });
      await w.loadURL('about:blank');
    });
    after(async () => {
      w.destroy();
    });

    async function rendererInvoke (...args: any[]) {
      const { ipcRenderer } = require('electron');
      try {
        const result = await ipcRenderer.invoke('test', ...args);
        ipcRenderer.send('result', { result });
      } catch (e) {
        ipcRenderer.send('result', { error: e.message });
      }
    }

    it('receives a response from a synchronous handler', async () => {
      ipcMain.handleOnce('test', (e: IpcMainInvokeEvent, arg: number) => {
        expect(arg).to.equal(123);
        return 3;
      });
      const done = new Promise(resolve => ipcMain.once('result', (e, arg) => {
        expect(arg).to.deep.equal({ result: 3 });
        resolve();
      }));
      await w.webContents.executeJavaScript(`(${rendererInvoke})(123)`);
      await done;
    });

    it('receives a response from an asynchronous handler', async () => {
      ipcMain.handleOnce('test', async (e: IpcMainInvokeEvent, arg: number) => {
        expect(arg).to.equal(123);
        await new Promise(resolve => setImmediate(resolve));
        return 3;
      });
      const done = new Promise(resolve => ipcMain.once('result', (e, arg) => {
        expect(arg).to.deep.equal({ result: 3 });
        resolve();
      }));
      await w.webContents.executeJavaScript(`(${rendererInvoke})(123)`);
      await done;
    });

    it('receives an error from a synchronous handler', async () => {
      ipcMain.handleOnce('test', () => {
        throw new Error('some error');
      });
      const done = new Promise(resolve => ipcMain.once('result', (e, arg) => {
        expect(arg.error).to.match(/some error/);
        resolve();
      }));
      await w.webContents.executeJavaScript(`(${rendererInvoke})()`);
      await done;
    });

    it('receives an error from an asynchronous handler', async () => {
      ipcMain.handleOnce('test', async () => {
        await new Promise(resolve => setImmediate(resolve));
        throw new Error('some error');
      });
      const done = new Promise(resolve => ipcMain.once('result', (e, arg) => {
        expect(arg.error).to.match(/some error/);
        resolve();
      }));
      await w.webContents.executeJavaScript(`(${rendererInvoke})()`);
      await done;
    });

    it('throws an error if no handler is registered', async () => {
      const done = new Promise(resolve => ipcMain.once('result', (e, arg) => {
        expect(arg.error).to.match(/No handler registered/);
        resolve();
      }));
      await w.webContents.executeJavaScript(`(${rendererInvoke})()`);
      await done;
    });

    it('throws an error when invoking a handler that was removed', async () => {
      ipcMain.handle('test', () => {});
      ipcMain.removeHandler('test');
      const done = new Promise(resolve => ipcMain.once('result', (e, arg) => {
        expect(arg.error).to.match(/No handler registered/);
        resolve();
      }));
      await w.webContents.executeJavaScript(`(${rendererInvoke})()`);
      await done;
    });

    it('forbids multiple handlers', async () => {
      ipcMain.handle('test', () => {});
      try {
        expect(() => { ipcMain.handle('test', () => {}); }).to.throw(/second handler/);
      } finally {
        ipcMain.removeHandler('test');
      }
    });
  });

  describe('ordering', () => {
    let w = (null as unknown as BrowserWindow);

    before(async () => {
      w = new BrowserWindow({ show: false, webPreferences: { nodeIntegration: true } });
      await w.loadURL('about:blank');
    });
    after(async () => {
      w.destroy();
    });

    it('between send and sendSync is consistent', async () => {
      const received: number[] = [];
      ipcMain.on('test-async', (e, i) => { received.push(i); });
      ipcMain.on('test-sync', (e, i) => { received.push(i); e.returnValue = null; });
      const done = new Promise(resolve => ipcMain.once('done', () => { resolve(); }));
      function rendererStressTest () {
        const { ipcRenderer } = require('electron');
        for (let i = 0; i < 1000; i++) {
          switch ((Math.random() * 2) | 0) {
            case 0:
              ipcRenderer.send('test-async', i);
              break;
            case 1:
              ipcRenderer.sendSync('test-sync', i);
              break;
          }
        }
        ipcRenderer.send('done');
      }
      try {
        w.webContents.executeJavaScript(`(${rendererStressTest})()`);
        await done;
      } finally {
        ipcMain.removeAllListeners('test-async');
        ipcMain.removeAllListeners('test-sync');
      }
      expect(received).to.have.lengthOf(1000);
      expect(received).to.deep.equal([...received].sort((a, b) => a - b));
    });

    it('between send, sendSync, and invoke is consistent', async () => {
      const received: number[] = [];
      ipcMain.handle('test-invoke', (e, i) => { received.push(i); });
      ipcMain.on('test-async', (e, i) => { received.push(i); });
      ipcMain.on('test-sync', (e, i) => { received.push(i); e.returnValue = null; });
      const done = new Promise(resolve => ipcMain.once('done', () => { resolve(); }));
      function rendererStressTest () {
        const { ipcRenderer } = require('electron');
        for (let i = 0; i < 1000; i++) {
          switch ((Math.random() * 3) | 0) {
            case 0:
              ipcRenderer.send('test-async', i);
              break;
            case 1:
              ipcRenderer.sendSync('test-sync', i);
              break;
            case 2:
              ipcRenderer.invoke('test-invoke', i);
              break;
          }
        }
        ipcRenderer.send('done');
      }
      try {
        w.webContents.executeJavaScript(`(${rendererStressTest})()`);
        await done;
      } finally {
        ipcMain.removeHandler('test-invoke');
        ipcMain.removeAllListeners('test-async');
        ipcMain.removeAllListeners('test-sync');
      }
      expect(received).to.have.lengthOf(1000);
      expect(received).to.deep.equal([...received].sort((a, b) => a - b));
    });
  });
});