New tests for App.events & Sprite.events

scripts/events.lua

@@ -0,0 +1,89 @@
+-- Copyright (C) 2021  Igara Studio S.A.
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+dofile('./test_utils.lua')
+
+if false then
+-- Test app.events
+do
+  local i = 0
+  local listener = app.events:on('sitechange',
+                                 function() i = i + 1 end)
+  assert(i == 0)
+  local a = Sprite(32, 32)
+  expect_eq(a, app.activeSprite)
+  expect_eq(1, i)
+  local b = Sprite(32, 32)
+  expect_eq(b, app.activeSprite)
+  expect_eq(2, i)
+  app.activeSprite = a
+  expect_eq(3, i)
+  app.events:off(listener)
+  app.activeSprite = b
+  expect_eq(3, i)
+end
+
+-- Test Sprite.events
+do
+  local spr = Sprite(32, 64)
+  local changes = 0
+  function incChanges() changes = changes + 1 end
+  spr.events:on('change', incChanges)
+  expect_eq(0, changes)
+  spr.width = 64
+  expect_eq(1, changes)
+  app.undo()
+  expect_eq(2, changes)
+  app.redo()
+  expect_eq(3, changes)
+  spr.events:off(incChanges)
+  app.undo()
+  expect_eq(3, changes)
+end
+
+end
+
+-- Multiple listeners
+do
+  local spr = Sprite(2, 2)
+  local ai, bi = 0, 0
+  function a() ai = ai + 1 end
+  function b() bi = bi + 1 end
+
+  spr.events:on('change', a)
+  spr.events:on('change', b)
+  spr.width = 4
+  expect_eq(1, ai)
+  expect_eq(1, bi)
+
+  spr.events:off(a)
+  spr.width = 8
+  expect_eq(1, ai)
+  expect_eq(2, bi)
+
+  spr.events:off(b)
+  spr.width = 16
+  expect_eq(1, ai)
+  expect_eq(2, bi)
+end
+
+-- Avoid removing invalid listener when we use Events:off(function)
+do
+  local spr = Sprite(2, 2)
+
+  local i = 0
+  function inc() i = i + 1 end
+  spr.events:on('change', inc)
+
+  spr.width = 4
+  expect_eq(1, i)
+
+  app.events:off(inc)
+  spr.width = 8
+
+  -- If this fails is because app.events:off(inc) removed the sprite
+  -- listener instead of doing nothing.
+  expect_eq(2, i)
+end