Tauri App Dev

Tauri 2.0 App Development

Tauri is a framework for building small, fast, secure desktop apps using web frontends and Rust backends.

Architecture Overview

┌─────────────────────────────────────────┐
│           Frontend (Webview)            │
│     HTML/CSS/JS • React/Vue/Svelte      │
└────────────────┬────────────────────────┘
                 │ IPC (invoke/events)
┌────────────────▼────────────────────────┐
│           Tauri Core (Rust)             │
│  Commands • State • Plugins • Events    │
└────────────────┬────────────────────────┘
                 │ TAO (windows) + WRY (webview)
┌────────────────▼────────────────────────┐
│          Operating System               │
│   macOS • Windows • Linux • Mobile      │
└─────────────────────────────────────────┘

Project Structure

my-app/
├── src/                    # Frontend source
├── src-tauri/
│   ├── Cargo.toml          # Rust dependencies
│   ├── tauri.conf.json     # Tauri configuration
│   ├── capabilities/       # Security permissions (v2)
│   │   └── default.json
│   ├── src/
│   │   ├── main.rs         # Desktop entry point
│   │   └── lib.rs          # Main app logic + mobile entry
│   └── icons/
└── package.json

Commands (Frontend → Rust)

Define commands in Rust with #[tauri::command]:

// src-tauri/src/lib.rs
#[tauri::command]
fn greet(name: String) -> String {
    format!("Hello, {}!", name)
}

#[tauri::command]
async fn read_file(path: String) -> Result<String, String> {
    std::fs::read_to_string(&path).map_err(|e| e.to_string())
}

pub fn run() {
    tauri::Builder::default()
        .invoke_handler(tauri::generate_handler![greet, read_file])
        .run(tauri::generate_context!())
        .expect("error running app");
}

Call from frontend (direct):

import { invoke } from '@tauri-apps/api/core';

const greeting = await invoke<string>('greet', { name: 'World' });
const content = await invoke<string>('read_file', { path: '/tmp/test.txt' });

Project convention: Wrap invoke() with TanStack Query for caching and state management:

import { useQuery, useMutation } from '@tanstack/react-query';
import { invoke } from '@tauri-apps/api/core';

// Query (read operations)
const { data: content } = useQuery({
  queryKey: ['file', path],
  queryFn: () => invoke<string>('read_file', { path }),
});

// Mutation (write operations)
const { mutate: saveFile } = useMutation({
  mutationFn: (content: string) => invoke('write_file', { path, content }),
});

Key rules:

• Arguments must implement serde::Deserialize
• Return types must implement serde::Serialize
• Use Result<T, E> for fallible operations
• Async commands run on thread pool (non-blocking)
• Snake_case in Rust → camelCase in JS arguments

State Management

Share state across commands:

use std::sync::Mutex;
use tauri::State;

struct AppState {
    counter: Mutex<i32>,
    db: Mutex<Option<Database>>,
}

#[tauri::command]
fn increment(state: State<'_, AppState>) -> i32 {
    let mut counter = state.counter.lock().unwrap();
    *counter += 1;
    *counter
}

pub fn run() {
    tauri::Builder::default()
        .manage(AppState {
            counter: Mutex::new(0),
            db: Mutex::new(None),
        })
        .invoke_handler(tauri::generate_handler![increment])
        .run(tauri::generate_context!())
        .expect("error running app");
}

Access via AppHandle (for background threads):

use tauri::Manager;

#[tauri::command]
async fn background_task(app: tauri::AppHandle) {
    let state = app.state::<AppState>();
    // use state...
}

Events (Rust → Frontend)

Emit events from Rust:

use tauri::Emitter;

#[tauri::command]
fn start_process(app: tauri::AppHandle) {
    std::thread::spawn(move || {
        for i in 0..100 {
            app.emit("progress", i).unwrap();
            std::thread::sleep(std::time::Duration::from_millis(50));
        }
        app.emit("complete", "Done!").unwrap();
    });
}

Listen in frontend:

import { listen } from '@tauri-apps/api/event';

const unlisten = await listen<number>('progress', (event) => {
    console.log(`Progress: ${event.payload}%`);
});

// Clean up when done
unlisten();

Essential Plugins

Install plugins: cargo add <plugin> in src-tauri, pnpm add <package> in frontend.

Register in Rust:

pub fn run() {
    tauri::Builder::default()
        .plugin(tauri_plugin_fs::init())
        .plugin(tauri_plugin_dialog::init())
        .plugin(tauri_plugin_clipboard_manager::init())
        .run(tauri::generate_context!())
        .expect("error running app");
}

Security: Capabilities & Permissions

Tauri 2.0 uses capabilities (in src-tauri/capabilities/) to control what APIs each window can access.

src-tauri/capabilities/default.json:

{
  "$schema": "../gen/schemas/desktop-schema.json",
  "identifier": "main-capability",
  "windows": ["main"],
  "permissions": [
    "core:default",
    "fs:default",
    "fs:allow-read-text-file",
    "dialog:default",
    {
      "identifier": "fs:scope",
      "allow": [{ "path": "$APPDATA/**" }, { "path": "$DOCUMENT/**" }]
    }
  ]
}

Scope variables: $APPDATA, $APPCONFIG, $DOCUMENT, $DOWNLOAD, $HOME, $TEMP, etc.

File Operations (Editor Pattern)

import { open, save } from '@tauri-apps/plugin-dialog';
import { readTextFile, writeTextFile } from '@tauri-apps/plugin-fs';

// Open file dialog
const path = await open({
    filters: [{ name: 'Markdown', extensions: ['md'] }],
    multiple: false,
});

if (path) {
    const content = await readTextFile(path);
    // Edit content...
    await writeTextFile(path, modifiedContent);
}

// Save as dialog
const savePath = await save({
    filters: [{ name: 'Markdown', extensions: ['md'] }],
    defaultPath: 'untitled.md',
});

if (savePath) {
    await writeTextFile(savePath, content);
}

Window Management

Create windows at runtime:

use tauri::{WebviewUrl, WebviewWindowBuilder};

#[tauri::command]
async fn open_settings(app: tauri::AppHandle) -> Result<(), String> {
    WebviewWindowBuilder::new(&app, "settings", WebviewUrl::App("settings.html".into()))
        .title("Settings")
        .inner_size(600.0, 400.0)
        .build()
        .map_err(|e| e.to_string())?;
    Ok(())
}

Configure in tauri.conf.json:

{
  "app": {
    "windows": [
      {
        "label": "main",
        "title": "My App",
        "width": 1200,
        "height": 800,
        "decorations": true,
        "resizable": true
      }
    ]
  }
}

Custom Titlebar

Set decorations: false in config, then:

<div data-tauri-drag-region class="titlebar">
    <span>My App</span>
    <button id="minimize">−</button>
    <button id="maximize">□</button>
    <button id="close">×</button>
</div>

import { getCurrentWindow } from '@tauri-apps/api/window';

const appWindow = getCurrentWindow();
document.getElementById('minimize')?.addEventListener('click', () => appWindow.minimize());
document.getElementById('maximize')?.addEventListener('click', () => appWindow.toggleMaximize());
document.getElementById('close')?.addEventListener('click', () => appWindow.close());

Building & Distribution

# Development
pnpm tauri dev

# Production build
pnpm tauri build

# Build specific targets
pnpm tauri build --target universal-apple-darwin  # macOS universal
pnpm tauri build --bundles deb,appimage           # Linux only
pnpm tauri build --bundles nsis                   # Windows NSIS

Output locations:

• macOS: target/release/bundle/macos/*.app, *.dmg
• Windows: target/release/bundle/nsis/*-setup.exe, msi/*.msi
• Linux: target/release/bundle/deb/*.deb, appimage/*.AppImage

Quick Reference

Test-Driven Development (TDD)

CRITICAL: Always follow TDD - write tests BEFORE implementation.

TDD Workflow

1. RED    → Write failing test first
2. GREEN  → Write minimal code to pass
3. REFACTOR → Clean up, keep tests green

Testing Stack

E2E Testing with Tauri MCP

IMPORTANT: Always use tauri_* MCP tools for testing the running app. Do NOT use chrome-devtools MCP - it's for browser pages only.

// Tauri MCP workflow for E2E tests:

// 1. Start session (connect to running Tauri app)
tauri_driver_session({ action: 'start', port: 9223 })

// 2. Take snapshot (get DOM state)
tauri_webview_screenshot()
tauri_webview_find_element({ selector: '.editor-content' })

// 3. Interact with app
tauri_webview_interact({ action: 'click', selector: '#save-button' })
tauri_webview_keyboard({ action: 'type', selector: 'input', text: 'hello' })

// 4. Wait for results
tauri_webview_wait_for({ type: 'selector', value: '.success-toast' })

// 5. Verify IPC calls
tauri_ipc_monitor({ action: 'start' })
tauri_ipc_get_captured({ filter: 'save_file' })

// 6. Check backend state
tauri_ipc_execute_command({ command: 'get_app_state' })

// 7. Read logs for debugging
tauri_read_logs({ source: 'console', lines: 50 })

Rust Unit Tests

// src-tauri/src/lib.rs

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_greet() {
        let result = greet("World".to_string());
        assert_eq!(result, "Hello, World!");
    }

    #[test]
    fn test_parse_markdown() {
        let input = "# Hello";
        let result = parse_markdown(input);
        assert!(result.is_ok());
        assert_eq!(result.unwrap().title, "Hello");
    }

    #[tokio::test]
    async fn test_async_command() {
        let result = read_file("/tmp/test.txt".to_string()).await;
        // Test with temp files or mocks
    }
}

Run: cd src-tauri && cargo test

React Component Tests (Vitest)

// src/components/Editor.test.tsx
import { describe, it, expect, vi } from 'vitest'
import { render, screen } from '@testing-library/react'
import userEvent from '@testing-library/user-event'
import { Editor } from './Editor'

// Mock Tauri invoke
vi.mock('@tauri-apps/api/core', () => ({
  invoke: vi.fn()
}))

describe('Editor', () => {
  it('should render editor content', () => {
    render(<Editor initialValue="# Hello" />)
    expect(screen.getByText('Hello')).toBeInTheDocument()
  })

  it('should call save on Ctrl+S', async () => {
    const { invoke } = await import('@tauri-apps/api/core')
    render(<Editor initialValue="test" />)

    await userEvent.keyboard('{Control>}s{/Control}')

    expect(invoke).toHaveBeenCalledWith('save_file', expect.any(Object))
  })
})

Zustand Store Tests

// src/stores/editorStore.test.ts
import { describe, it, expect, beforeEach } from 'vitest'
import { useEditorStore } from './editorStore'

describe('editorStore', () => {
  beforeEach(() => {
    // Reset store before each test
    useEditorStore.setState({
      content: '',
      isDirty: false,
      filePath: null
    })
  })

  it('should update content and mark dirty', () => {
    const { setContent } = useEditorStore.getState()

    setContent('new content')

    const state = useEditorStore.getState()
    expect(state.content).toBe('new content')
    expect(state.isDirty).toBe(true)
  })

  it('should clear dirty flag after save', () => {
    useEditorStore.setState({ isDirty: true })
    const { markSaved } = useEditorStore.getState()

    markSaved()

    expect(useEditorStore.getState().isDirty).toBe(false)
  })
})

Integration Tests with Mocked IPC

// src/features/file/useFileOperations.test.ts
import { describe, it, expect, vi, beforeEach } from 'vitest'
import { renderHook, waitFor } from '@testing-library/react'
import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
import { useFileOperations } from './useFileOperations'

vi.mock('@tauri-apps/api/core', () => ({
  invoke: vi.fn()
}))

vi.mock('@tauri-apps/plugin-dialog', () => ({
  open: vi.fn(),
  save: vi.fn()
}))

describe('useFileOperations', () => {
  let queryClient: QueryClient

  beforeEach(() => {
    queryClient = new QueryClient({
      defaultOptions: { queries: { retry: false } }
    })
    vi.clearAllMocks()
  })

  it('should open file and load content', async () => {
    const { invoke } = await import('@tauri-apps/api/core')
    const { open } = await import('@tauri-apps/plugin-dialog')

    vi.mocked(open).mockResolvedValue('/path/to/file.md')
    vi.mocked(invoke).mockResolvedValue('# File Content')

    const { result } = renderHook(() => useFileOperations(), {
      wrapper: ({ children }) => (
        <QueryClientProvider client={queryClient}>
          {children}
        </QueryClientProvider>
      )
    })

    await result.current.openFile()

    await waitFor(() => {
      expect(invoke).toHaveBeenCalledWith('read_file', { path: '/path/to/file.md' })
    })
  })
})

TDD Example: Adding a New Feature

// Step 1: RED - Write failing test first
// src/features/wordcount/useWordCount.test.ts
describe('useWordCount', () => {
  it('should count words in content', () => {
    const { result } = renderHook(() => useWordCount('hello world'))
    expect(result.current.words).toBe(2)
  })

  it('should handle empty content', () => {
    const { result } = renderHook(() => useWordCount(''))
    expect(result.current.words).toBe(0)
  })

  it('should count characters', () => {
    const { result } = renderHook(() => useWordCount('hello'))
    expect(result.current.characters).toBe(5)
  })
})

// Step 2: GREEN - Minimal implementation
// src/features/wordcount/useWordCount.ts
export function useWordCount(content: string) {
  return {
    words: content.trim() ? content.trim().split(/\s+/).length : 0,
    characters: content.length
  }
}

// Step 3: REFACTOR - Add memoization, types, etc.
export function useWordCount(content: string): WordCountResult {
  return useMemo(() => ({
    words: content.trim() ? content.trim().split(/\s+/).length : 0,
    characters: content.length,
    charactersNoSpaces: content.replace(/\s/g, '').length
  }), [content])
}

Running Tests

# All tests
pnpm test

# Watch mode
pnpm test:watch

# Coverage
pnpm test:coverage

# Rust tests only
cd src-tauri && cargo test

# Type check + lint + test
pnpm check:all

Debugging Tips

• DevTools: Right-click → Inspect, or Cmd+Option+I (macOS) / Ctrl+Shift+I (Windows/Linux)
• Rust logs: Use log crate + tauri-plugin-log or println! (visible in terminal)
• Check capabilities: "Not allowed" errors mean missing permissions in capabilities
• IPC errors: Ensure argument names match (snake_case Rust → camelCase JS)
• E2E debugging: Use tauri_read_logs({ source: 'console' }) to see webview console

Related Skills

• tauri-v2-integration — VMark-specific Tauri IPC patterns (invoke/emit bridges, menu accelerators)
• tauri-mcp-testing — E2E testing of the running Tauri app via MCP tools
• rust-tauri-backend — VMark Rust backend (commands, menu items, filesystem)