feat: add ipcRenderer.invoke() (#18449)

spec-main/api-ipc-spec.ts

@@ -0,0 +1,109 @@
+import * as chai from 'chai'
+import * as chaiAsPromised from 'chai-as-promised'
+import { BrowserWindow, ipcMain, IpcMainInvokeEvent } from 'electron'
+
+const { expect } = chai
+
+chai.use(chaiAsPromised)
+
+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', () => {})
+      expect(() => { ipcMain.handle('test', () => {}) }).to.throw(/second handler/)
+      ipcMain.removeHandler('test')
+    })
+  })
+})