fix: allow Tray with title only (without icon) on Mac (#13851)

spec/api-tray-spec.js

@@ -2,18 +2,18 @@ const {remote} = require('electron')
 const {Menu, Tray, nativeImage} = remote
 
 describe('tray module', () => {
+  let tray
+
+  beforeEach(() => {
+    tray = new Tray(nativeImage.createEmpty())
+  })
+
+  afterEach(() => {
+    tray.destroy()
+    tray = null
+  })
+
   describe('tray.setContextMenu', () => {
-    let tray
-
-    beforeEach(() => {
-      tray = new Tray(nativeImage.createEmpty())
-    })
-
-    afterEach(() => {
-      tray.destroy()
-      tray = null
-    })
-
     it('accepts menu instance', () => {
       tray.setContextMenu(new Menu())
     })
@@ -22,4 +22,26 @@ describe('tray module', () => {
       tray.setContextMenu(null)
     })
   })
+
+  describe('tray.setImage', () => {
+    it('accepts empty image', () => {
+      tray.setImage(nativeImage.createEmpty())
+    })
+  })
+
+  describe('tray.setPressedImage', () => {
+    it('accepts empty image', () => {
+      tray.setPressedImage(nativeImage.createEmpty())
+    })
+  })
+
+  describe('tray.setTitle', () => {
+    it('accepts non-empty string', () => {
+      tray.setTitle('Hello World!')
+    })
+
+    it('accepts empty string', () => {
+      tray.setTitle('')
+    })
+  })
 })