@tauri-apps/api/mocks

Test helpers that stand in for the Tauri backend.

Importing any other module of this package in a plain Node/browser test environment fails, because there is no window.__TAURI_INTERNALS__ to talk to. The functions here install a fake one: mockIPC intercepts invoke calls, mockWindows makes the window/webview APIs believe a set of windows exists, and mockConvertFileSrc makes convertFileSrc return the URL shape of a given platform.

Call clearMocks after each test when your runner reuses the same window object between tests.

Example

import { beforeEach, afterEach, expect, test } from 'vitest';
import { mockIPC, clearMocks } from '@tauri-apps/api/mocks';
import { invoke } from '@tauri-apps/api/core';

afterEach(() => {
  clearMocks();
});

test('greet', async () => {
  mockIPC((cmd, args) => {
    if (cmd === 'greet') {
      return `Hello, ${(args as { name: string }).name}!`;
    }
  });

  await expect(invoke('greet', { name: 'tauri' })).resolves.toBe('Hello, tauri!');
});

This package is also accessible with window.__TAURI__.mocks when app.withGlobalTauri in tauri.conf.json is set to true.

Functions

clearMocks()

function clearMocks(): void;

Defined in: packages/api/src/mocks.ts:355

Clears mocked functions/data injected by the other functions in this module. When using a test runner that doesn’t provide a fresh window object for each test, calling this function will reset tauri specific properties.

Example

import { mockWindows, clearMocks } from "@tauri-apps/api/mocks"

afterEach(() => {
   clearMocks()
})

test("mocked windows", () => {
   mockWindows("main", "second", "third");

   expect(window.__TAURI_INTERNALS__).toHaveProperty("metadata")
})

test("no mocked windows", () => {
   expect(window.__TAURI_INTERNALS__).not.toHaveProperty("metadata")
})

Returns

void

Since

1.0.0

---

mockConvertFileSrc()

function mockConvertFileSrc(osName: string): void;

Defined in: packages/api/src/mocks.ts:316

Mock convertFileSrc function

Example

import { mockConvertFileSrc } from "@tauri-apps/api/mocks";
import { convertFileSrc } from "@tauri-apps/api/core";

mockConvertFileSrc("windows")

const url = convertFileSrc("C:\\Users\\user\\file.txt")

Parameters

Parameter	Type	Description
osName	string	The operating system to mock, can be one of linux, macos, or windows

Returns

void

Since

1.6.0

---

mockIPC()

function mockIPC(cb: (cmd: string, payload?: InvokeArgs) => unknown, options?: MockIPCOptions): void;

Defined in: packages/api/src/mocks.ts:143

Intercepts all IPC requests with the given mock handler.

This function can be used when testing tauri frontend applications or when running the frontend in a Node.js context during static site generation.

Examples

Testing setup using Vitest:

import { mockIPC, clearMocks } from "@tauri-apps/api/mocks"
import { invoke } from "@tauri-apps/api/core"

afterEach(() => {
   clearMocks()
})

test("mocked command", () => {
 mockIPC((cmd, payload) => {
  switch (cmd) {
    case "add":
      return (payload.a as number) + (payload.b as number);
    default:
      break;
    }
 });

 expect(invoke('add', { a: 12, b: 15 })).resolves.toBe(27);
})

The callback function can also return a Promise:

import { mockIPC, clearMocks } from "@tauri-apps/api/mocks"
import { invoke } from "@tauri-apps/api/core"

afterEach(() => {
   clearMocks()
})

test("mocked command", () => {
 mockIPC((cmd, payload) => {
  if(cmd === "get_data") {
   return fetch("https://example.com/data.json")
     .then((response) => response.json())
  }
 });

 expect(invoke('get_data')).resolves.toBe({ foo: 'bar' });
})

listen can also be mocked with direct calls to the emit function. This functionality is opt-in via the shouldMockEvents option:

import { mockIPC, clearMocks } from "@tauri-apps/api/mocks"
import { emit, listen } from "@tauri-apps/api/event"

afterEach(() => {
   clearMocks()
})

test("mocked event", () => {
 mockIPC(() => {}, { shouldMockEvents: true }); // enable event mocking

 const eventHandler = vi.fn();
 listen('test-event', eventHandler); // typically in component setup or similar

 emit('test-event', { foo: 'bar' });
 expect(eventHandler).toHaveBeenCalledWith({
   event: 'test-event',
   payload: { foo: 'bar' }
 });
})

emitTo is currently not supported by this mock implementation.

Parameters

Parameter	Type
cb	(cmd: string, payload?: InvokeArgs) => unknown
options?	MockIPCOptions

Returns

void

Since

1.0.0

---

mockWindows()

function mockWindows(current: string, ..._additionalWindows: string[]): void;

Defined in: packages/api/src/mocks.ts:287

Mocks one or many window labels. In non-tauri context it is required to call this function before using the @tauri-apps/api/window module.

This function only mocks the presence of windows, window properties (e.g. width and height) can be mocked like regular IPC calls using the mockIPC function.

Examples

import { mockWindows } from "@tauri-apps/api/mocks";
import { getCurrentWindow } from "@tauri-apps/api/window";

mockWindows("main", "second", "third");

const win = getCurrentWindow();

win.label // "main"

import { mockWindows } from "@tauri-apps/api/mocks";

mockWindows("main", "second", "third");

mockIPC((cmd, args) => {
 if (cmd === "plugin:event|emit") {
   console.log('emit event', args?.event, args?.payload);
 }
});

const { emit } = await import("@tauri-apps/api/event");
await emit('loaded'); // this will cause the mocked IPC handler to log to the console.

Parameters

Parameter	Type	Description
current	string	Label of window this JavaScript context is running in.
…_additionalWindows	string[]	-

Returns

void

Since

1.0.0

Interfaces

MockIPCOptions

Defined in: packages/api/src/mocks.ts:62

Options for mockIPC.

Options shouldMockEvents: If true, the listen and emit functions will be mocked, allowing you to test event handling without a real backend. This will consume any events emitted with the plugin:event prefix.

Since

2.7.0

Properties

Property	Type	Defined in
shouldMockEvents?	boolean	packages/api/src/mocks.ts:63