Merge pull request 'feature/task' (#29) from feature/task into main

Reviewed-on: #29

lib/animation_node.lua

@@ -1,6 +1,5 @@
 local easing = require "lib.utils.easing"
 
---- @alias voidCallback fun(): nil
 --- @alias animationRunner fun(node: AnimationNode)
 
 --- Узел дерева анимаций.
@@ -23,6 +22,7 @@ local easing = require "lib.utils.easing"
 ---         }
 ---     }:run()
 --- ```
+--- @deprecated
 --- @class AnimationNode
 --- @field count integer
 --- @field run animationRunner
@@ -73,6 +73,7 @@ function animation:update(dt)
     end
 end
 
+--- @deprecated
 --- @param data {[1]: animationRunner?, onEnd?: voidCallback, duration: number?, easing: ease?, children?: AnimationNode[]}
 --- @return AnimationNode
 local function new(data)

lib/annotations.lua

@@ -8,3 +8,6 @@ Tree.behaviors.light           = require "character.behaviors.light"
 Tree.behaviors.positioned      = require "character.behaviors.positioned"
 Tree.behaviors.tiled           = require "character.behaviors.tiled"
 Tree.behaviors.cursor          = require "character.behaviors.cursor"
+Tree.behaviors.ai              = require "lib.character.behaviors.ai"
+
+--- @alias voidCallback fun(): nil

lib/character/behaviors/ai.lua

@@ -0,0 +1,59 @@
+local AnimationNode = require "lib.animation_node"
+local easing        = require "lib.utils.easing"
+
+local function closestCharacter(char)
+    local caster = Vec3 {}
+    char:try(Tree.behaviors.positioned, function(b)
+        caster = b.position
+    end)
+    local charTarget
+    local minDist = 88005553535 -- spooky magic number
+    for k, v in pairs(Tree.level.characters) do
+        v:try(Tree.behaviors.positioned, function(b)
+            local dist = ((caster.x - b.position.x) ^ 2 + (caster.y - b.position.y) ^ 2) ^ 0.5
+            if dist < minDist and dist ~= 0 then
+                minDist = dist
+                charTarget = v
+            end
+            -- print(k, b.position)
+        end)
+    end
+    return charTarget
+end
+
+--- @class AIBehavior : Behavior
+--- @field animationNode AnimationNode?
+--- @field target Vec3?
+local behavior = {}
+behavior.__index = behavior
+behavior.id = "ai"
+
+function behavior.new()
+    return setmetatable({}, behavior)
+end
+
+--- @return Task<nil>
+function behavior:makeTurn()
+    return function(callback) -- почему так, описано в Task
+        self.owner:try(Tree.behaviors.spellcaster, function(spellB)
+            local charTarget = closestCharacter(self.owner)
+            charTarget:try(Tree.behaviors.positioned, function(b)
+                self.target = Vec3 { b.position.x, b.position.y + 1 } --- @todo тут захардкожено + 1, но мы должны как-то хитро определять с какой стороны обойти
+            end)
+
+            spellB.spellbook[1]:cast(self.owner, self.target)(function()
+                -- здесь мы оказываемся после того, как сходили в первый раз
+                print("[AI]: finished move 1")
+                local newTarget = Vec3 { 1, 1 }
+                -- поэтому позиция персонажа для нового каста пересчитается динамически
+                spellB.spellbook[1]:cast(self.owner, newTarget)(function()
+                    print("[AI]: finished move 2")
+                    -- дергаем функцию после завершения хода
+                    callback()
+                end)
+            end)
+        end)
+    end
+end
+
+return behavior

lib/character/behaviors/light.lua

@@ -1,13 +1,17 @@
+local AnimationNode = require "lib.animation_node"
+local easing        = require "lib.utils.easing"
+
 --- @class LightBehavior : Behavior
 --- @field intensity number
 --- @field color Vec3
 --- @field seed integer
 --- @field colorAnimationNode? AnimationNode
+--- @field private animateColorCallback? fun(): nil
 --- @field targetColor? Vec3
 --- @field sourceColor? Vec3
-local behavior = {}
+local behavior      = {}
-behavior.__index = behavior
+behavior.__index    = behavior
-behavior.id = "light"
+behavior.id         = "light"
 
 ---@param values {intensity: number?, color: Vec3?, seed: integer?}
 ---@return LightBehavior
@@ -26,11 +30,24 @@ function behavior:update(dt)
     self.colorAnimationNode:update(dt)
 end
 
-function behavior:animateColor(targetColor, animationNode)
+--- @TODO: refactor
+function behavior:animateColor(targetColor)
     if self.colorAnimationNode then self.colorAnimationNode:finish() end
-    self.colorAnimationNode = animationNode
+    self.colorAnimationNode = AnimationNode {
+        function(_) end,
+        easing = easing.easeInQuad,
+        duration = 800,
+        onEnd = function()
+            if self.animateColorCallback then self.animateColorCallback() end
+        end
+    }
+    self.colorAnimationNode:run()
     self.sourceColor = self.color
     self.targetColor = targetColor
+
+    return function(callback)
+        self.animateColorCallback = callback
+    end
 end
 
 function behavior:draw()

lib/character/behaviors/residentsleeper.lua

@@ -1,21 +1,37 @@
 --- Умеет асинхронно ждать какое-то время (для анимаций)
 --- @class ResidentSleeperBehavior : Behavior
---- @field animationNode? AnimationNode
+--- @field private t0 number?
+--- @field private sleepTime number?
+--- @field private callback voidCallback?
+--- @field private state 'running' | 'finished'
 local behavior = {}
 behavior.__index = behavior
 behavior.id = "residentsleeper"
 
 function behavior.new() return setmetatable({}, behavior) end
 
-function behavior:update(dt)
+function behavior:update(_)
-    if not self.animationNode then return end
+    if self.state ~= 'running' then return end
-    self.animationNode:update(dt)
+
+    local t = love.timer.getTime()
+    if t >= self.t0 + self.sleepTime then
+        self.state = 'finished'
+        self.callback()
+    end
 end
 
---- @param node AnimationNode
+--- @return Task<nil>
-function behavior:sleep(node)
+function behavior:sleep(ms)
-    if self.animationNode then self.animationNode:finish() end
+    self.sleepTime = ms / 1000
-    self.animationNode = node
+    return function(callback)
+        if self.state == 'running' then
+            self.callback()
+        end
+
+        self.t0 = love.timer.getTime()
+        self.callback = callback
+        self.state = 'running'
+    end
 end
 
 return behavior

lib/character/behaviors/sprite.lua

@@ -69,17 +69,20 @@ function sprite:draw()
     )
 end
 
---- @param node AnimationNode
+--- @return Task<nil>
-function sprite:animate(state, node)
+function sprite:animate(state)
-    if not self.animationGrid[state] then
+    return function(callback)
-        return print("[SpriteBehavior]: no animation for '" .. state .. "'")
+        if not self.animationGrid[state] then
+            print("[SpriteBehavior]: no animation for '" .. state .. "'")
+            callback()
+        end
+        self.animationTable[state] = anim8.newAnimation(self.animationGrid[state], self.ANIMATION_SPEED,
+            function()
+                self:loop("idle")
+                callback()
+            end)
+        self.state = state
     end
-    self.animationTable[state] = anim8.newAnimation(self.animationGrid[state], self.ANIMATION_SPEED,
-        function()
-            self:loop("idle")
-            node:finish()
-        end)
-    self.state = state
 end
 
 function sprite:loop(state)

lib/character/behaviors/tiled.lua

@@ -5,7 +5,7 @@ local utils = require "lib.utils.utils"
 --- @field private runSource? Vec3 точка, из которой бежит персонаж
 --- @field private runTarget? Vec3 точка, в которую в данный момент бежит персонаж
 --- @field private path? Deque путь, по которому сейчас бежит персонаж
---- @field private animationNode? AnimationNode AnimationNode, с которым связана анимация перемещения
+--- @field private followPathCallback? fun()
 --- @field private t0 number время начала движения
 --- @field size Vec3
 local behavior = {}
@@ -20,10 +20,8 @@ function behavior.new(size)
 end
 
 --- @param path Deque
---- @param animationNode AnimationNode
+--- @return Task<nil>
-function behavior:followPath(path, animationNode)
+function behavior:followPath(path)
-    if path:is_empty() then return animationNode:finish() end
-    self.animationNode = animationNode
     self.owner:try(Tree.behaviors.sprite, function(sprite)
         sprite:loop("run")
     end)
@@ -32,6 +30,10 @@ function behavior:followPath(path, animationNode)
     local nextCell = path:peek_front()
     self:runTo(nextCell)
     path:pop_front()
+
+    return function(callback)
+        self.followPathCallback = callback
+    end
 end
 
 --- @param target Vec3
@@ -72,7 +74,10 @@ function behavior:update(dt)
                     sprite:loop("idle")
                 end)
                 self.runTarget = nil
-                if self.animationNode then self.animationNode:finish() end
+
+                if self.followPathCallback then
+                    self.followPathCallback()
+                end
             end
         else                                                                           -- анимация перемещения не завершена
             positioned.position = utils.lerp(self.runSource, self.runTarget, fraction) -- линейный интерполятор

lib/level/grid/base.lua

@@ -8,7 +8,7 @@ grid.__index = grid
 --- adds a value to the grid
 --- @param value any
 function grid:add(value)
-    grid[tostring(value.position)] = value
+    self.__grid[tostring(value.position)] = value
 end
 
 --- @param position Vec3

lib/level/selector.lua

@@ -37,9 +37,16 @@ function selector:update(dt)
                 if not selectedId then self:select(nil) end
                 return
             end
-            if b.cast:cast(char, mousePosition) then
+            local task = b.cast:cast(char, mousePosition) -- в task функция, которая запускает анимацию спелла
+            if task then
                 self:lock()
                 b.state = "running"
+
+                task(
+                    function(_) -- это коллбэк, который сработает по окончании анимации спелла
+                        b:endCast()
+                    end
+                )
             end
         end)
     end

lib/level/turn_order.lua

@@ -34,6 +34,15 @@ function turnOrder:next()
     local next = self.pendingQueue:peek()
     if not next then return self:endRound() end
     self.current = self.pendingQueue:pop()
+
+    local char = Tree.level.characters[self.current]
+    char:try(Tree.behaviors.ai, function(ai)
+        Tree.level.selector:lock()
+        ai:makeTurn()(function()
+            Tree.level.selector:unlock()
+            self:next()
+        end)
+    end)
 end
 
 --- Меняем местами очередь сходивших и не сходивших (пустую)

lib/simple_ui/level/end_turn.lua

@@ -57,7 +57,7 @@ function endTurnButton:onClick()
         end,
         duration = 1500,
         easing = easing.easeInOutCubic,
-        onEnd = function() Tree.level.selector:select(cid) end
+        onEnd = function() if not playing:has(Tree.behaviors.ai) then Tree.level.selector:select(cid) end end
     }:run()
 end
 

lib/spellbook.lua

@@ -7,23 +7,22 @@
 --- --TODO: каждый каст должен возвращать объект, который позволит отследить момент завершения анимации спелла
 --- Да, это Future/Promise/await/async
 
-local AnimationNode = require "lib.animation_node"
+local task    = require 'lib.utils.task'
-local easing        = require "lib.utils.easing"
 
 --- @class Spell Здесь будет много бойлерплейта, поэтому тоже понадобится спеллмейкерский фреймворк, который просто вернет готовый Spell
 --- @field tag string
 --- @field update fun(self: Spell, caster: Character, dt: number): nil Изменяет состояние спелла
 --- @field draw fun(self: Spell): nil Рисует превью каста, ничего не должна изменять в идеальном мире
---- @field cast fun(self: Spell, caster: Character, target: Vec3): boolean Вызывается в момент каста, изменяет мир. Возвращает bool в зависимости от того, получилось ли скастовать
+--- @field cast fun(self: Spell, caster: Character, target: Vec3): Task<nil> | nil Вызывается в момент каста, изменяет мир.
-local spell         = {}
+local spell   = {}
-spell.__index       = spell
+spell.__index = spell
-spell.tag           = "base"
+spell.tag     = "base"
 
 function spell:update(caster, dt) end
 
 function spell:draw() end
 
-function spell:cast(caster, target) return true end
+function spell:cast(caster, target) return end
 
 local walk = setmetatable({
     --- @type Deque
@@ -35,30 +34,28 @@ function walk:cast(caster, target)
     if not caster:try(Tree.behaviors.stats, function(stats)
             return stats.mana >= 2
         end) then
-        return false
+        return
     end
 
-    local path = require "lib.pathfinder" (caster:has(Tree.behaviors.positioned).position:floor(), target)
+    local initialPos = caster:has(Tree.behaviors.positioned).position:floor()
+    local path = require "lib.pathfinder" (initialPos, target)
     path:pop_front()
-    if path:is_empty() then return false end
+    if path:is_empty() then
-
+        print("[Walk]: the path is empty", initialPos, target)
-    for p in path:values() do print(p) end
+        return
+    end
 
     caster:try(Tree.behaviors.stats, function(stats)
         stats.mana = stats.mana - 2
-        print(stats.mana)
     end)
 
     local sprite = caster:has(Tree.behaviors.sprite)
-    if not sprite then return true end
+    assert(sprite, "[Walk]", "WTF DUDE WHERE'S YOUR SPRITE")
-    AnimationNode {
+    if not sprite then
-        function(node)
+        return
-            caster:has(Tree.behaviors.tiled):followPath(path, node)
+    end
-        end,
-        onEnd = function() caster:has(Tree.behaviors.spellcaster):endCast() end,
-    }:run()
 
-    return true
+    return caster:has(Tree.behaviors.tiled):followPath(path)
 end
 
 function walk:update(caster, dt)
@@ -90,9 +87,10 @@ function regenerateMana:cast(caster, target)
         stats.mana = 10
         stats.initiative = stats.initiative + 10
     end)
-    print(caster.id, "has regenerated mana and gained initiative")
+
     local sprite = caster:has(Tree.behaviors.sprite)
-    if not sprite then return true end
+    if not sprite then return nil end
+    print(caster.id, "has regenerated mana and gained initiative")
 
     local light = require "lib/character/character".spawn("Light Effect")
     light:addBehavior {
@@ -100,26 +98,11 @@ function regenerateMana:cast(caster, target)
         Tree.behaviors.residentsleeper.new(),
         Tree.behaviors.positioned.new(caster:has(Tree.behaviors.positioned).position + Vec3 { 0.5, 0.5 }),
     }
-    AnimationNode {
-        function(node)
-            local audioPath = Tree.assets.files.audio
-            sprite:animate("hurt", node)
-            Tree.audio:crossfade(audioPath.music.level1.battle,
-                audioPath.music.level1.choral, 5000)
-        end,
-        onEnd = function() caster:has(Tree.behaviors.spellcaster):endCast() end
-    }:run()
 
-    AnimationNode {
+    return task.wait {
-        function(node)
+        light:has(Tree.behaviors.light):animateColor(Vec3 {}),
-            light:has(Tree.behaviors.light):animateColor(Vec3 {}, node)
+        sprite:animate("hurt")
-        end,
+    }
-        easing = easing.easeInQuad,
-        duration = 800,
-        onEnd = function() light:die() end
-    }:run()
-
-    return true
 end
 
 local attack = setmetatable({}, spell)
@@ -131,7 +114,7 @@ function attack:cast(caster, target)
             print("dist:", dist)
             return dist > 2
         end) then
-        return false
+        return
     end
 
     caster:try(Tree.behaviors.stats, function(stats)
@@ -140,7 +123,7 @@ function attack:cast(caster, target)
 
     --- @type Character
     local targetCharacterId = Tree.level.characterGrid:get(target)
-    if not targetCharacterId or targetCharacterId == caster.id then return false end
+    if not targetCharacterId or targetCharacterId == caster.id then return end
     local targetCharacter = Tree.level.characters[targetCharacterId]
     targetCharacter:try(Tree.behaviors.stats, function(stats)
         stats.hp = stats.hp - 4
@@ -148,43 +131,20 @@ function attack:cast(caster, target)
 
     local sprite = caster:has(Tree.behaviors.sprite)
     local targetSprite = targetCharacter:has(Tree.behaviors.sprite)
-    if not sprite or not targetSprite then return true end
+    if not sprite or not targetSprite then return end
 
     caster:try(Tree.behaviors.positioned, function(b) b:lookAt(target) end)
 
-    AnimationNode {
+    return
-        onEnd = function() caster:has(Tree.behaviors.spellcaster):endCast() end,
+        task.wait {
-        children = {
+            sprite:animate("attack"),
-            AnimationNode {
+            task.wait {
-                function(node)
+                task.chain(targetCharacter:has(Tree.behaviors.residentsleeper):sleep(200),
-                    sprite:animate("attack", node)
+                    function() return targetSprite:animate("hurt") end
-                end
+                ),
-            },
+                Tree.audio:play(Tree.assets.files.audio.sounds.hurt)
-            AnimationNode {
-                function(node)
-                    targetCharacter:has(Tree.behaviors.residentsleeper):sleep(node)
-                end,
-                duration = 200,
-                children = {
-                    AnimationNode {
-                        function(node)
-                            local audioPath = Tree.assets.files.audio
-                            targetSprite:animate("hurt", node)
-                            --- @type SourceFilter
-                            local settings = {
-                                type = "highpass",
-                                volume = 1,
-                                lowgain = 0.1
-                            }
-                            Tree.audio:play(audioPath.sounds.hurt, settings)
-                        end
-                    }
-                }
             }
         }
-    }:run()
-
-    return true
 end
 
 ----------------------------------------
@@ -199,6 +159,7 @@ local spellbook = {
 function spellbook.of(list)
     local spb = {}
     for i, sp in ipairs(list) do
+        print(i)
         spb[i] = setmetatable({}, { __index = sp })
     end
     return spb

lib/utils/counter.lua

@@ -0,0 +1,40 @@
+--- @class Counter
+--- @field private count integer
+--- @field private onFinish fun(): nil
+--- @field private isAlive boolean
+--- @field push fun():nil добавить 1 к счетчику
+--- @field pop fun():nil убавить 1 у счетчика
+--- @field set fun(count: integer): nil установить значение на счетчике
+local counter = {}
+counter.__index = counter
+
+
+--- @private
+function counter:_push()
+    self.count = self.count + 1
+end
+
+--- @private
+function counter:_pop()
+    self.count = self.count - 1
+    if self.count == 0 and self.isAlive then
+        self.isAlive = false
+        self.onFinish()
+    end
+end
+
+--- @param onFinish fun(): nil
+local function new(onFinish)
+    local t = {
+        count = 0,
+        onFinish = onFinish,
+        isAlive = true,
+    }
+    t.push = function() counter._push(t) end
+    t.pop = function() counter._pop(t) end
+    t.set = function(count) t.count = count end
+
+    return setmetatable(t, counter)
+end
+
+return new

lib/utils/task.lua

@@ -0,0 +1,83 @@
+--- Обобщенная асинхронная функция
+---
+--- Использование в общих чертах выглядит так:
+--- ```lua
+--- local multiplyByTwoCallback = nil
+--- local n = nil
+--- local function multiplyByTwoAsync(number)
+---     -- императивно сохраняем/обрабатываем параметр
+---     n = number
+---     return function(callback) -- это функция, которая запускает задачу
+---         multiplyByTwoCallback = callback
+---     end
+--- end
+---
+--- local function update(dt)
+---     --- ждем нужного момента времени...
+---
+---     if multiplyByTwoCallback then -- завершаем вычисление
+---         local result = n * 2
+---         multiplyByTwoCallback(result) -- результат асинхронного вычисления идет в параметр коллбека!
+---         multiplyByTwoCallback = nil
+---     end
+--- end
+---
+---
+--- --- потом это можно вызывать так:
+--- local task = multiplyByTwoAsync(21)
+--- -- это ленивое вычисление, так что в этот момент ничего не произойдет
+--- -- запускаем
+--- task(
+---     function(result) print(result) end -- выведет 42 после завершения вычисления, т.е. аналогично `task.then((res) => print(res))` на JS
+--- )
+---
+--- ```
+--- @generic T
+--- @alias Task<T> fun(callback: fun(value: T): nil): nil
+
+--- Возвращает новый Task, который завершится после завершения всех переданных `tasks`.
+---
+--- Значение созданного Task будет содержать список значений `tasks` в том же порядке.
+---
+--- См. также https://api.dart.dev/dart-async/Future/wait.html
+--- @generic T
+--- @param tasks Task[]
+--- @return Task<T[]>
+local function wait(tasks)
+    local count = #tasks
+    local results = {}
+
+    return function(callback)
+        for i, task in ipairs(tasks) do
+            task(
+                function(result)
+                    results[i] = result
+
+                    count = count - 1
+                    if count == 0 then callback(results) end
+                end
+            )
+        end
+    end
+end
+
+
+--- Последовательно объединяет два `Task` в один.
+--- @generic T
+--- @generic R
+--- @param task Task<T> `Task`, который выполнится первым
+--- @param onCompleted fun(value: T): Task<R> Конструктор второго `Task`. Принимает результат выполнения первого `Task`
+--- @return Task<R>
+local function chain(task, onCompleted)
+    return function(callback)
+        task(function(value)
+            local task2 = onCompleted(value)
+            task2(callback)
+        end)
+    end
+end
+
+return {
+    wait = wait,
+    chain = chain
+}

main.lua

@@ -2,6 +2,8 @@
 
 local character = require "lib/character/character"
 local testLayout
+local TestRunner = require "test.runner"
+TestRunner:register(require "test.task")
 
 function love.conf(t)
     t.console = true
@@ -23,16 +25,37 @@ function love.load()
                 Tree.behaviors.shadowcaster.new(),
                 Tree.behaviors.spellcaster.new()
             },
-        character.spawn("Baris")
+        character.spawn("Foodor")
             :addBehavior {
                 Tree.behaviors.residentsleeper.new(),
                 Tree.behaviors.stats.new(nil, nil, 1),
-                Tree.behaviors.positioned.new(Vec3 { 5, 5 }),
+                Tree.behaviors.positioned.new(Vec3 { 4, 3 }),
                 Tree.behaviors.tiled.new(),
                 Tree.behaviors.sprite.new(Tree.assets.files.sprites.character),
                 Tree.behaviors.shadowcaster.new(),
                 Tree.behaviors.spellcaster.new()
             },
+        character.spawn("Foodor")
+            :addBehavior {
+                Tree.behaviors.residentsleeper.new(),
+                Tree.behaviors.stats.new(nil, nil, 3),
+                Tree.behaviors.positioned.new(Vec3 { 5, 3 }),
+                Tree.behaviors.tiled.new(),
+                Tree.behaviors.sprite.new(Tree.assets.files.sprites.character),
+                Tree.behaviors.shadowcaster.new(),
+                Tree.behaviors.spellcaster.new()
+            },
+        character.spawn("Baris")
+            :addBehavior {
+                Tree.behaviors.residentsleeper.new(),
+                Tree.behaviors.stats.new(nil, nil, 2),
+                Tree.behaviors.positioned.new(Vec3 { 5, 5 }),
+                Tree.behaviors.tiled.new(),
+                Tree.behaviors.sprite.new(Tree.assets.files.sprites.character),
+                Tree.behaviors.shadowcaster.new(),
+                Tree.behaviors.spellcaster.new(),
+                Tree.behaviors.ai.new()
+            },
     }
 
     for id, _ in pairs(chars) do
@@ -46,6 +69,8 @@ end
 
 local lt = "0"
 function love.update(dt)
+    TestRunner:update(dt) -- закомментировать для отключения тестов
+
     local t1 = love.timer.getTime()
     Tree.controls:poll()
     Tree.level.camera:update(dt) -- сначала логика камеры, потому что на нее завязан UI

test/runner.lua

@@ -0,0 +1,46 @@
+--- @class Test
+local test = {}
+function test:run(complete) end
+
+function test:update(dt) end
+
+--- @class TestRunner
+--- @field private tests Test[]
+--- @field private state "loading" | "running" | "completed"
+--- @field private completedCount integer
+local runner = {}
+runner.tests = {}
+runner.state = "loading"
+runner.completedCount = 0
+
+--- глобальный update для тестов, нужен для тестирования фич, зависимых от времени
+function runner:update(dt)
+    if self.state == "loading" then
+        print("[TestRunner]: running " .. #self.tests .. " tests")
+
+        for _, t in ipairs(self.tests) do
+            t:run(
+                function()
+                    self.completedCount = self.completedCount + 1
+                    if self.completedCount == #self.tests then
+                        self.state = "completed"
+                        print("[TestRunner]: tests completed")
+                    end
+                end
+            )
+        end
+        self.state = "running"
+    end
+
+    for _, t in ipairs(self.tests) do
+        if t.update then t:update(dt) end
+    end
+end
+
+--- добавляет тест для прохождения
+--- @param t Test
+function runner:register(t)
+    table.insert(self.tests, t)
+end
+
+return runner

test/task.lua

@@ -0,0 +1,75 @@
+local task = require "lib.utils.task"
+
+local test = {}
+
+local t0
+local task1Start, task2Start
+local task1Callback, task2Callback
+
+--- @return Task<number>
+local function task1()
+    return function(callback)
+        task1Start = love.timer.getTime()
+        task1Callback = callback
+    end
+end
+
+--- @return Task<number>
+local function task2()
+    return function(callback)
+        task2Start = love.timer.getTime()
+        task2Callback = callback
+    end
+end
+
+function test:run(complete)
+    t0 = love.timer.getTime()
+
+    task.wait {
+        task1(),
+        task2()
+    } (function(values)
+            local tWait = love.timer.getTime()
+            local dt = tWait - t0
+
+            local t1 = values[1]
+            local t2 = values[2]
+
+            assert(type(t1) == "number" and type(t2) == "number")
+            assert(t2 > t1)
+            assert(dt >= 2, "dt = " .. dt)
+
+            print("task.wait completed in " .. dt .. " sec", "t1 = " .. t1 - t0, "t2 = " .. t2 - t0)
+
+
+            t0 = love.timer.getTime()
+            task.chain(task1(), function(value)
+                t1 = value
+                assert(t1 - t0 >= 1)
+                return task2()
+            end)(
+                    function(value)
+                        t2 = value
+                        assert(t2 - t0 >= 2)
+                        print("task.chain completed in " .. t2 - t0 .. " sec")
+
+                        complete()
+                    end
+                )
+        end)
+end
+
+function test:update(dt)
+    local t = love.timer.getTime()
+    if task1Start and t - task1Start >= 1 then
+        task1Callback(t)
+        task1Start = nil
+    end
+
+    if task2Start and t - task2Start >= 2 then
+        task2Callback(t)
+        task2Start = nil
+    end
+end
+
+return test