fix!: use promise:new instead of promise.new

In Lua convention, create an object always carry `self`, so we must
break change for further development.

Create an promise object:
```lua
local p = promise:new(function(resolve, reject) end)
-- or
local p = promise(function(resolve, reject) end)
```

README.md

@@ -101,7 +101,7 @@ Summary up the API different from JavaScript.
 
 | JavaScript                                          | Lua                                             |
 | --------------------------------------------------- | ----------------------------------------------- |
-| `new Promise`                                       | `Promise.new`/`Promise`                         |
+| `new Promise`                                       | `Promise:new`/`Promise`                         |
 | `Promise.then`                                      | `Promise:thenCall`, `then` is language keyword  |
 | `Promise.catch`                                     | `Promise:catch`                                 |
 | `Promise.finally`                                   | `Promise:finally`                               |

examples/demo.lua

@@ -15,7 +15,7 @@ local function setTimeout(callback, ms)
 end
 
 local function defuse(ms)
-    return promise.new(function(resolve, reject)
+    return promise:new(function(resolve, reject)
         setTimeout(function()
             resolve(ms)
         end, ms)

lua/async.lua

@@ -55,7 +55,7 @@ function Async.sync(executor)
     local isCallable, fn = utils.getCallable(executor, typ)
     assert(isCallable, 'a callable table or function expected, got ' .. typ)
     injectENV(fn)
-    return promise.new(function(resolve, reject)
+    return promise:new(function(resolve, reject)
         local co = coroutine.create(typ == 'function' and executor or function()
             return executor()
         end)

lua/promise.lua

@@ -22,7 +22,7 @@ local REJECTED = 3
 ---@field err? PromiseAsyncError
 local Promise = setmetatable({_id = promiseId}, {
     __call = function(self, executor)
-        return self.new(executor)
+        return self:new(executor)
     end
 })
 Promise.__index = Promise
@@ -241,11 +241,9 @@ resolvePromise = function(promise, value)
     end
 end
 
-function Promise.new(executor)
+function Promise:new(executor)
     utils.assertType(executor, 'function')
-    ---@type Promise
-    local o = setmetatable({}, Promise)
-
+    local o = self == Promise and setmetatable({}, self) or self
     o.state = PENDING
     o.result = nil
     o.queue = {}
@@ -258,7 +256,7 @@ function Promise.new(executor)
 end
 
 function Promise:thenCall(onFulfilled, onRejected)
-    local o = Promise.new(noop)
+    local o = self.new(Promise, noop)
     table.insert(self.queue, {o, onFulfilled, onRejected})
     if self.state ~= PENDING then
         handleQueue(self)
@@ -292,7 +290,7 @@ function Promise.resolve(value)
     if Promise.isInstance(value, typ) then
         return value
     else
-        local o = Promise.new(noop)
+        local o = Promise:new(noop)
         local thenCall = getThenable(value, typ)
         if thenCall then
             wrapExecutor(o, thenCall, value)
@@ -305,7 +303,7 @@ function Promise.resolve(value)
 end
 
 function Promise.reject(reason)
-    local o = Promise.new(noop)
+    local o = Promise:new(noop)
     o.state = REJECTED
     o.result = reason
     handleRejection(o)
@@ -314,7 +312,7 @@ end
 
 function Promise.all(values)
     utils.assertType(values, 'table')
-    return Promise.new(function(resolve, reject)
+    return Promise:new(function(resolve, reject)
         local res = {}
         local cnt = 0
         for k, v in pairs(values) do
@@ -337,7 +335,7 @@ end
 
 function Promise.allSettled(values)
     utils.assertType(values, 'table')
-    return Promise.new(function(resolve, reject)
+    return Promise:new(function(resolve, reject)
         local res = {}
         local cnt = 0
         local _ = reject
@@ -362,7 +360,7 @@ end
 
 function Promise.any(values)
     utils.assertType(values, 'table')
-    return Promise.new(function(resolve, reject)
+    return Promise:new(function(resolve, reject)
         local cnt = 0
         local function rejectAggregateError()
             if cnt == 0 then
@@ -386,7 +384,7 @@ end
 
 function Promise.race(values)
     utils.assertType(values, 'table')
-    return Promise.new(function(resolve, reject)
+    return Promise:new(function(resolve, reject)
         for _, p in pairs(values) do
             Promise.resolve(p):thenCall(function(value)
                 resolve(value)

typings/promise.lua

@@ -12,7 +12,7 @@ local Promise = {}
 ---a resolve callback used to resolve the promise with a value or the result of another promise,
 ---and a reject callback used to reject the promise with a provided reason or error.
 ---@return Promise promise A new Promise.
-function Promise.new(executor) end
+function Promise:new(executor) end
 
 ---Attaches callbacks for the resolution and/or rejection of the Promise.
 ---@param onFulfilled? fun(value: any): any The callback to execute when the Promise is resolved.