Announce: "I'm using dev-test-hammerspoon for macOS desktop automation."

<EXTREMELY-IMPORTANT> ## Gate Reminder

Before taking screenshots or running E2E tests, you MUST complete all 6 gates from dev-tdd:

GATE 1: BUILD
GATE 2: LAUNCH (with file-based logging)
GATE 3: WAIT
GATE 4: CHECK PROCESS
GATE 5: READ LOGS ← MANDATORY, CANNOT SKIP
GATE 6: VERIFY LOGS
THEN: E2E tests/screenshots

You loaded dev-tdd earlier. Follow the gates now. </EXTREMELY-IMPORTANT>

Contents

• Tool Availability Gate
• When to Use Hammerspoon
• Hammerspoon Setup
• Input Simulation
• Application Control
• Window Management
• Screenshots
• Complete E2E Example
• Alternative: cliclick

macOS Desktop Automation

<EXTREMELY-IMPORTANT> ## Tool Availability Gate

Verify Hammerspoon is installed before proceeding.

# Check Hammerspoon installation (both CLI and app)
which hs || echo "MISSING: hs CLI"
ls /Applications/Hammerspoon.app 2>/dev/null || echo "MISSING: Hammerspoon.app"

If missing:

STOP: Cannot proceed with macOS automation.

Missing tool: Hammerspoon (required for macOS E2E testing)

Install with:
  brew install --cask hammerspoon

After installing:
  1. Open Hammerspoon.app
  2. Grant Accessibility permissions in System Preferences
  3. In Hammerspoon console, run: hs.ipc.cliInstall()
  4. Add to ~/.hammerspoon/init.lua: require("hs.ipc")

Reply when installed and I'll continue testing.

This gate is non-negotiable. Missing tools = full stop. </EXTREMELY-IMPORTANT>

<EXTREMELY-IMPORTANT> ## When to Use Hammerspoon

Use Hammerspoon for:

• macOS native application automation
• System-wide keyboard shortcuts
• Window management and positioning
• Menu item automation
• Clipboard verification
• Multi-app workflows on macOS

Do not use Hammerspoon for:

• Testing web applications (use Chrome MCP or Playwright)
• Cross-platform testing needed
• Linux desktop automation (use dev-test-linux)

For web testing, use:

• Read("${CLAUDE_PLUGIN_ROOT}/lib/skills/dev-test-chrome/SKILL.md")

  - debugging

• Read("${CLAUDE_PLUGIN_ROOT}/lib/skills/dev-test-playwright/SKILL.md")

  - CI/CD

Rationalization Prevention

Thought	Reality
"I can use AppleScript instead"	Hammerspoon is more reliable for automation
"I'll test the app manually"	AUTOMATE IT with Hammerspoon
"Web testing tools work for desktop apps"	NO. Use Hammerspoon for native apps
"Accessibility permissions are too hard"	One-time setup. Do it.
"The app is too complex to automate"	Break it into testable steps

</EXTREMELY-IMPORTANT>

Hammerspoon Setup

One-time setup in

~/.hammerspoon/init.lua

:

require("hs.ipc")  -- Enables CLI

Reload config after changes:

hs -c 'hs.reload()'  # Reload Hammerspoon configuration

Input Simulation

hs.eventtap - Keyboard/Mouse

-- Type text (simulates keystrokes)
hs.eventtap.keyStrokes("hello world")

-- Key press with modifiers
hs.eventtap.keyStroke({"cmd"}, "c")           -- Cmd+C
hs.eventtap.keyStroke({"cmd", "shift"}, "s")  -- Cmd+Shift+S
hs.eventtap.keyStroke({"ctrl", "alt"}, "t")   -- Ctrl+Alt+T
hs.eventtap.keyStroke({}, "return")           -- Enter key
hs.eventtap.keyStroke({}, "escape")           -- Escape key

-- Function keys
hs.eventtap.keyStroke({}, "f1")
hs.eventtap.keyStroke({"cmd"}, "f5")

-- Mouse clicks
hs.eventtap.leftClick({x=100, y=200})
hs.eventtap.rightClick({x=100, y=200})
hs.eventtap.middleClick({x=100, y=200})
hs.eventtap.doubleClick({x=100, y=200})

-- Mouse movement
hs.mouse.absolutePosition({x=500, y=300})

-- Scroll
hs.eventtap.scrollWheel({0, -5}, {})  -- Scroll down
hs.eventtap.scrollWheel({0, 5}, {})   -- Scroll up

Running from CLI

# Execute Lua code directly
hs -c 'hs.eventtap.keyStroke({"cmd"}, "c")'  # Run inline Lua code via CLI

# Execute a script file
hs /path/to/test_script.lua  # Run Hammerspoon script from file

# Pipe script via stdin
echo 'hs.eventtap.keyStrokes("test")' | hs -s  # Run script piped through stdin

Application Control

hs.application

-- Launch or focus app by name
local app = hs.application.launchOrFocus("Safari")

-- Launch app by bundle ID
hs.application.launchOrFocusByBundleID("com.apple.Safari")

-- Get running app
local app = hs.application.get("Safari")
if app then
    app:activate()       -- Bring to front
    app:hide()           -- Hide
    app:unhide()         -- Unhide
    app:kill()           -- Terminate gracefully
    app:kill9()          -- Force kill
end

-- Get frontmost app
local front = hs.application.frontmostApplication()
print(front:name())
print(front:bundleID())

-- List all running apps
for _, app in ipairs(hs.application.runningApplications()) do
    print(app:name())
end

-- Wait for app to launch
hs.timer.waitUntil(
    function() return hs.application.get("MyApp") ~= nil end,
    function() print("App launched") end,
    0.5  -- Check every 0.5 seconds
)

Menu Items

-- Click menu item
local app = hs.application.get("Safari")
app:selectMenuItem({"File", "New Window"})
app:selectMenuItem({"Edit", "Paste"})

-- Check if menu item exists
local menuItem = app:findMenuItem({"File", "Save"})
if menuItem then
    print("Save is available, enabled:", menuItem.enabled)
end

Window Management

hs.window

-- Get focused window
local win = hs.window.focusedWindow()
print(win:title())
print(win:frame())  -- {x, y, w, h}

-- Get app's windows
local app = hs.application.get("Safari")
local wins = app:allWindows()
for _, win in ipairs(wins) do
    print(win:title())
end

-- Get window by title (partial match)
local win = hs.window.get("My Document")

-- Window actions
win:focus()           -- Focus window
win:maximize()        -- Maximize
win:minimize()        -- Minimize to dock
win:close()           -- Close window

-- Move/resize
win:setFrame({x=100, y=100, w=800, h=600})
win:move({100, 0})    -- Move relative
win:setSize({800, 600})
win:centerOnScreen()

-- Get window position and size
local frame = win:frame()
print("Position:", frame.x, frame.y)
print("Size:", frame.w, frame.h)

Screenshots

<EXTREMELY-IMPORTANT> ### The Iron Law of Visual Verification

Every E2E test MUST include screenshot evidence.

After completing a workflow, capture a screenshot to prove success. </EXTREMELY-IMPORTANT>

screencapture (CLI)

# Full screen (all displays)
screencapture /tmp/screenshot.png  # Capture entire screen to file

# Main screen only
screencapture -m /tmp/main_screen.png  # Capture primary screen only

# Specific window (interactive - click to select)
screencapture -w /tmp/window.png  # Interactively select window to capture

# Specific region
screencapture -R 100,200,800,600 /tmp/region.png  # Capture rectangular region (x,y,w,h)

# Without window shadow
screencapture -o /tmp/no_shadow.png  # Capture without window shadows

# Silent (no camera sound)
screencapture -x /tmp/silent.png  # Capture silently without shutter sound

# To clipboard instead of file
screencapture -c  # Capture to clipboard

# Combined: silent, no shadow, specific region
screencapture -x -o -R 0,0,1920,1080 /tmp/clean.png  # Capture region silently without shadows

hs.screen (Hammerspoon)

-- Capture focused window
local win = hs.window.focusedWindow()
if win then
    local img = win:snapshot()
    img:saveToFile("/tmp/window.png")
end

-- Capture entire screen
local screen = hs.screen.mainScreen()
local img = screen:snapshot()
img:saveToFile("/tmp/screen.png")

-- Capture specific region
local img = hs.screen.mainScreen():snapshot({x=0, y=0, w=800, h=600})
img:saveToFile("/tmp/region.png")

Complete E2E Example

<EXTREMELY-IMPORTANT> ### E2E Test Structure

Every Hammerspoon E2E test MUST:

1. Launch - Start the application
2. Verify launch - Assert app is running
3. Interact - Perform user actions
4. Verify state - Check expected state (clipboard, window, etc.)
5. Screenshot - Capture visual evidence
6. Cleanup - Close app, restore state </EXTREMELY-IMPORTANT>

-- test_workflow.lua
-- Run with: hs /path/to/test_workflow.lua

local function test_app_workflow()
    -- 1. Launch app
    print("Launching app...")
    hs.application.launchOrFocus("TextEdit")
    hs.timer.usleep(1000000)  -- Wait 1 second

    -- 2. Verify app launched
    local app = hs.application.get("TextEdit")
    assert(app, "FAIL: TextEdit did not launch")
    print("App launched: " .. app:name())

    -- 3. Create new document
    hs.eventtap.keyStroke({"cmd"}, "n")
    hs.timer.usleep(500000)

    -- 4. Type content
    hs.eventtap.keyStrokes("Hello, this is an automated test!")
    hs.timer.usleep(300000)

    -- 5. Select all and copy
    hs.eventtap.keyStroke({"cmd"}, "a")
    hs.timer.usleep(100000)
    hs.eventtap.keyStroke({"cmd"}, "c")

    -- 6. Verify clipboard
    local clipboard = hs.pasteboard.getContents()
    assert(clipboard:find("automated test"), "FAIL: Clipboard doesn't match")
    print("Clipboard verified: " .. clipboard)

    -- 7. Take screenshot
    local win = hs.window.focusedWindow()
    local img = win:snapshot()
    img:saveToFile("/tmp/test_result.png")
    print("Screenshot saved to /tmp/test_result.png")

    -- 8. Close without saving
    hs.eventtap.keyStroke({"cmd"}, "w")
    hs.timer.usleep(500000)
    hs.eventtap.keyStroke({}, "d")  -- "Don't Save" button

    print("PASS: Workflow completed successfully")
end

-- Run the test
local status, err = pcall(test_app_workflow)
if not status then
    print("FAIL: " .. tostring(err))
    os.exit(1)
end
os.exit(0)

Run from CLI:

hs /path/to/test_workflow.lua && echo "TEST PASSED" || echo "TEST FAILED"  # Execute test script and report result

Alternative: cliclick

For simpler needs,

cliclick

provides CLI-based mouse/keyboard control:

# Install cliclick tool
brew install cliclick

# Mouse click at coordinates
cliclick c:100,200       # Left-click at coordinates
cliclick rc:100,200      # Right-click at coordinates
cliclick dc:100,200      # Double-click at coordinates

# Move mouse
cliclick m:500,300  # Move mouse to coordinates

# Type text
cliclick t:"Hello world"  # Type text at current cursor position

# Key press
cliclick kp:return  # Press return key
cliclick kp:escape  # Press escape key
cliclick kd:cmd kp:c ku:cmd  # Press Cmd+C (key down, press, key up)

# Wait (milliseconds)
cliclick w:500  # Wait for 500 milliseconds

cliclick is useful for simple scripts but lacks app control - prefer Hammerspoon for complex E2E tests.

Output Requirements

Every test run MUST be documented in LEARNINGS.md:

## macOS E2E Test: [Description]

**Tool:** Hammerspoon

**Script:**
```bash
hs /path/to/test_script.lua

Output:

Launching app...
App launched: TextEdit
Clipboard verified: Hello, this is an automated test!
Screenshot saved to /tmp/test_result.png
PASS: Workflow completed successfully

Result: PASS

Screenshot: /tmp/test_result.png

## Integration

This skill is referenced by `dev-test` for macOS desktop automation.

For TDD protocol, see: `Skill(skill="workflows:dev-tdd")`