create-app-e2e-test

Installation
SKILL.md

Create App E2E Test

You are an AI agent that creates app e2e tests for the Goose desktop app using the Tauri app test driver.

Goal

Given a test scenario in natural language, you will:

  1. Explore the app using the test driver CLI to discover what's on screen
  2. Write a Vitest test file that verifies the scenario using stable selectors

Do NOT read source code to understand the UI. Do not read .tsx, .ts, or .css files to find elements. Use snapshot to discover what is on the page — that is your only method. The one exception: read source code only when you need to add a data-testid attribute.

Prerequisites

The Tauri app must already be running in dev mode with the app test driver enabled.

Test Driver CLI

All exploration commands use the test driver client CLI:

pnpm test-driver <action> [selector] [value]

Available commands:

Command Description Example
snapshot Get a text DOM of visible elements pnpm test-driver snapshot
getText <selector> Get inner text of an element pnpm test-driver getText "h1"
count <selector> Count matching elements pnpm test-driver count "button"
click <selector> Click an element pnpm test-driver click "button"
fill <selector> <value> Fill an input/textarea pnpm test-driver fill "textarea" "hello"
keypress <selector> <key> Dispatch a keyboard event pnpm test-driver keypress "textarea" Enter
waitForText <text> Wait for text to appear in body (30s default) pnpm test-driver waitForText "Success"
scroll <direction> Scroll the page (up/down/top/bottom) pnpm test-driver scroll down
screenshot [path] Take a screenshot pnpm test-driver screenshot test.png

Snapshot Format

The snapshot command returns a simplified text DOM:

[e1] input type="text" placeholder="Ask anything..."
  [t1] label "Name:"
[e2] button "Send"
  [t2] span "Click me"
[t3] h1 "Good afternoon"
  • [eN] — interactive elements (input, button, select, textarea, a) with auto-assigned data-tid
  • [tN] — visible text nodes
  • Hidden elements are excluded
  • Indentation shows DOM hierarchy

data-tid attributes (e.g., [data-tid='e3']) are assigned dynamically during each snapshot and must not be used in test files — they change between runs.

Workflow

Phase 1: Explore

  1. Navigate to home first, then snapshot to see the current page state.

    pnpm test-driver click '[data-testid="nav-home"]'
    pnpm test-driver snapshot
    

    Tests always start from the home screen (useTestDriver() navigates home in beforeEach), so exploration should too.

  2. For each element you need to interact with or verify:

    • Identify it from the snapshot (e.g., [e3] button "Send")
    • Pick a stable selector using the Element Locating Strategy below — never use data-tid
    • Use count with that stable selector to verify it matches exactly one element
    • Use getText to verify text content
    • Use click/fill to perform actions during exploration
  3. After each action, run snapshot again — the DOM may have changed.

Example exploration session:

# 1. See what's on the page
pnpm test-driver snapshot

# 2. Pick a selector for the element you need, verify it matches exactly 1
pnpm test-driver count 'textarea[placeholder="Ask anything..."]'

# 3. Interact
pnpm test-driver fill 'textarea[placeholder="Ask anything..."]' "hello world"

# 4. Snapshot again to see the result
pnpm test-driver snapshot

Phase 2: Write the Test

Create a Vitest test file at tests/app-e2e/<name>.test.ts.

Use useTestDriver() from tests/app-e2e/lib/setup.ts to get a shared test driver connection with automatic teardown and screenshot-on-failure. See tests/app-e2e/chat.test.ts as a reference:

import { describe, it, expect } from "vitest";
import { useTestDriver } from "./lib/setup";

describe("<Feature>", () => {
  const testDriver = useTestDriver();

  it("does something", async () => {
    const text = await testDriver.getText('[data-testid="greeting"]');
    expect(text).toContain("Good");
  });
});

Test driver API methods available in tests:

  • testDriver.snapshot() → text DOM string
  • testDriver.getText(selector, { timeout? }) → inner text string
  • testDriver.count(selector) → number of matching elements
  • testDriver.click(selector, { timeout? }) → clicks element
  • testDriver.fill(selector, value, { timeout? }) → fills input/textarea
  • testDriver.keypress(selector, key, { timeout? }) → dispatches keyboard event
  • testDriver.waitForText(text, { selector?, timeout? }) → waits for text to appear (default: body, 30s)
  • testDriver.scroll(direction) → scrolls page ("up", "down", "top", "bottom")
  • testDriver.screenshot(path) → saves screenshot

All timeout options default to 5 seconds. waitForText defaults to 30 seconds.

Phase 3: Verify the Test

Run the test to make sure it passes:

pnpm test:app-e2e

If it fails, use the test driver CLI to re-explore. The issue could be a wrong selector, an incorrect assertion, or a bug in the app implementation.

Element Locating Strategy

Always verify uniqueness with count before using any selector in a test. If count > 1, the test will be flaky.

For each element, find a stable selector using this priority:

  1. data-testid (preferred): if the element already has a data-testid, use '[data-testid="my-element"]'.

    • Verify with count that it's unique
  2. Semantic selector: combine attributes, hierarchy, or roles to target a specific element.

    • 'input[placeholder="Ask anything..."]' — narrow by attribute value
    • '.sidebar [role="navigation"] a' — narrow by parent context
    • Always verify with count that the selector matches exactly 1 element
  3. Add a data-testid (last resort): if no stable selector exists, add a data-testid to the source code.

    • Names must be descriptive and include context (e.g., home-greeting not greeting, sidebar-new-chat-button not button)
    • Only add the data-testid attribute — do not change any other source code
    • Note the code change so it can be committed alongside the test

Never use data-tid attributes ([data-tid='e3']) in test files — they are assigned dynamically by snapshot and change between runs.

Rules

  • One test file per feature area (e.g., home.test.ts, sidebar.test.ts, settings.test.ts)
  • Keep test descriptions specific: "shows time-based greeting on home screen", not "home works"
  • Always check count === 1 for selectors before using them in assertions
  • Do not use snapshot in test assertions — it's for exploration only
  • The test driver automatically waits up to 5 seconds (configurable via { timeout }) for elements to appear before click, fill, getText, and keypress
  • Use waitForText to wait for specific text content to appear (e.g., after submitting a form or waiting for an LLM response)
  • If the DOM updates after an action, run snapshot again to see the new state before writing assertions
  • Do not add comments in test files — the test descriptions and code should be self-explanatory
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