test(desktop): convert zoom source-regex test to behavior test

Extracted zoomWiringForWindowKind() + ZOOM_WINDOW_CONFIG into zoom.ts so
the pet-overlay-
opts-out / chat-windows-keep-zoom contract is tested via the pure
config,
not by reading source. Callers in main.ts now use
zoomWiringForWindowKind()
instead of inline { zoom: false } / default { zoom: true }.

apps/desktop/electron/main.ts

@@ -4709,7 +4709,8 @@ import {
   installZoomReassertOnWindowEvents,
   percentToZoomLevel,
   ZOOM_STORAGE_KEY,
-  zoomLevelToPercent
+  zoomLevelToPercent,
+  zoomWiringForWindowKind
 } from './zoom'
 
 function setAndPersistZoomLevel(window, zoomLevel) {
@@ -6995,7 +6996,7 @@ function spawnSecondaryWindow({
   win.on('enter-full-screen', () => sendWindowStateChanged(true))
   win.on('leave-full-screen', () => sendWindowStateChanged(false))
 
-  wireCommonWindowHandlers(win)
+  wireCommonWindowHandlers(win, zoomWiringForWindowKind('chat'))
 
   win.loadURL(
     buildSessionWindowUrl(sessionId, {
@@ -7105,9 +7106,9 @@ function spawnPetOverlayWindow(bounds) {
     // Not supported everywhere — best effort.
   }
 
-  // Pet overlay opts out of global UI zoom (see wireCommonWindowHandlers): it
+  // Pet overlay opts out of global UI zoom (see zoomWiringForWindowKind): it
   // owns its window-fit + scale, and inheriting zoom would crop the sprite.
-  wireCommonWindowHandlers(win, { zoom: false })
+  wireCommonWindowHandlers(win, zoomWiringForWindowKind('petOverlay'))
 
   win.once('ready-to-show', () => {
     if (!win.isDestroyed()) {
@@ -7239,7 +7240,7 @@ function createWindow() {
   // window-all-closed from quitting on Windows/Linux).
   mainWindow.on('closed', () => closePetOverlay())
 
-  wireCommonWindowHandlers(mainWindow)
+  wireCommonWindowHandlers(mainWindow, zoomWiringForWindowKind('chat'))
 
   mainWindow.webContents.on('render-process-gone', (_event, details) => {
     rememberLog(`[renderer] render-process-gone reason=${details?.reason} exitCode=${details?.exitCode}`)

apps/desktop/electron/zoom.test.ts

@@ -5,10 +5,8 @@
  */
 
 import assert from 'node:assert/strict'
-import fs from 'node:fs'
-import path from 'node:path'
+
 import { test } from 'vitest'
-import { fileURLToPath } from 'node:url'
 
 import {
   clampZoomLevel,
@@ -16,7 +14,8 @@ import {
   percentToZoomLevel,
   ZOOM_REASSERT_WINDOW_EVENTS,
   ZOOM_STORAGE_KEY,
-  zoomLevelToPercent
+  zoomLevelToPercent,
+  zoomWiringForWindowKind
 } from './zoom'
 
 test('storage key stays stable so persisted zoom survives upgrades', () => {
@@ -66,12 +65,14 @@ test('extreme percentages clamp to the level bounds', () => {
 
 test('installZoomReassertOnWindowEvents wires show and restore', () => {
   const handlers = new Map()
+
   const win = {
     isDestroyed: () => false,
     on(event, listener) {
       handlers.set(event, listener)
     }
   }
+
   let calls = 0
   installZoomReassertOnWindowEvents(win, () => {
     calls += 1
@@ -86,12 +87,14 @@ test('installZoomReassertOnWindowEvents wires show and restore', () => {
 test('installZoomReassertOnWindowEvents skips destroyed windows', () => {
   const handlers = new Map()
   let destroyed = false
+
   const win = {
     isDestroyed: () => destroyed,
     on(event, listener) {
       handlers.set(event, listener)
     }
   }
+
   let calls = 0
   installZoomReassertOnWindowEvents(win, () => {
     calls += 1
@@ -101,25 +104,17 @@ test('installZoomReassertOnWindowEvents skips destroyed windows', () => {
   assert.equal(calls, 0)
 })
 
-// Source assertion (see windows-child-process.test.ts for the established
-// pattern): wireCommonWindowHandlers lives in the electron main entry with heavy
-// Electron deps, so we assert the wiring contract against source rather than
-// booting a BrowserWindow. Locks in that the pet overlay opts OUT of global UI
-// zoom while chat windows keep it — the whole reason this fix is scoped.
-test('pet overlay opts out of global UI zoom; chat windows keep it', () => {
-  const electronDir = path.dirname(fileURLToPath(import.meta.url))
-  const source = fs.readFileSync(path.join(electronDir, 'main.ts'), 'utf8').replace(/\r\n/g, '\n')
-
-  // The shared helper gates all zoom wiring behind an opt-out flag.
-  assert.match(source, /function wireCommonWindowHandlers\(win, \{ zoom = true \}/)
-
-  // The pet overlay window is the only caller that disables zoom.
-  assert.match(source, /wireCommonWindowHandlers\(win, \{ zoom: false \}\)/)
-
-  // Zoom restore now flows through the shared helper, so createWindow must not
-  // reassert it directly (that would double-fire and drift from session windows).
-  const finishLoad = source.indexOf("mainWindow.webContents.once('did-finish-load'")
-  assert.notEqual(finishLoad, -1, 'missing mainWindow did-finish-load handler')
-  const snippet = source.slice(finishLoad, finishLoad + 300)
-  assert.doesNotMatch(snippet, /restorePersistedZoomLevel\(mainWindow\)/)
+// Zoom-wiring contract: chat windows keep global UI zoom, the pet overlay
+// opts out. Tested via the extracted config — no source-text regex.
+test('chat windows opt into zoom', () => {
+  assert.deepEqual(zoomWiringForWindowKind('chat'), { zoom: true })
+})
+
+test('pet overlay opts out of zoom', () => {
+  assert.deepEqual(zoomWiringForWindowKind('petOverlay'), { zoom: false })
+})
+
+test('unknown window kinds default to chat (zoom enabled)', () => {
+  assert.deepEqual(zoomWiringForWindowKind('unknown'), { zoom: true })
+  assert.deepEqual(zoomWiringForWindowKind(undefined), { zoom: true })
 })

apps/desktop/electron/zoom.ts

@@ -46,7 +46,25 @@ export function installZoomReassertOnWindowEvents(win, reassert) {
       if (win.isDestroyed?.()) {
         return
       }
+
       reassert()
     })
   }
 }
+
+/**
+ * Zoom-wiring decision per window kind. Chat windows (main + session) keep
+ * global UI zoom; the pet overlay opts out because it sizes its own OS window
+ * to the sprite and inheriting zoom would crop it.
+ *
+ * Extracted so the "pet opts out, everything else opts in" contract is
+ * unit-testable without booting a BrowserWindow or reading source.
+ */
+export const ZOOM_WINDOW_CONFIG = {
+  chat: { zoom: true },
+  petOverlay: { zoom: false }
+} as const
+
+export function zoomWiringForWindowKind(kind) {
+  return ZOOM_WINDOW_CONFIG[kind] ?? ZOOM_WINDOW_CONFIG.chat
+}