From 258cbcc3f368e9f827100bc95e1fef773e9d93ed Mon Sep 17 00:00:00 2001
From: xiangnan <280145668@qq.com>
Date: Wed, 9 Oct 2024 22:05:46 +0800
Subject: [PATCH] feat:special handle multiple return functions. close 5

---
 README.md                             | 34 ++++++++++++++++++++++++++
 package.json                          |  2 +-
 src/App.vue                           |  2 +-
 src/js2lua.mjs                        | 35 +++++++++++++++++++++++++++
 src/jsInit.js                         |  2 ++
 test/multipleReturnForLuaFunction.mjs |  6 +++++
 6 files changed, 79 insertions(+), 2 deletions(-)
 create mode 100644 test/multipleReturnForLuaFunction.mjs

diff --git a/README.md b/README.md
index e0cc0b9..359cacb 100644
--- a/README.md
+++ b/README.md
@@ -88,6 +88,7 @@ js2lua(`let a = 1`, { importStatementHoisting: true });
 * [index0To1](#index0To1)
 * [keywords](#keywords)
 * [loop](#loop)
+* [multipleReturnForLuaFunction](#multipleReturnForLuaFunction)
 * [object](#object)
 * [operator](#operator)
 * [optionalNullish](#optionalNullish)
@@ -662,6 +663,39 @@ do
     end
 end
 
+```
+## multipleReturnForLuaFunction
+### js
+```js
+let [ok, res] = pcall(foo)
+let [ok2, res2] = xpcall(foo)
+let [e1, e2] = unpack(bar)
+// comparision
+let [ok3, res3] = pcall2(foo)
+let [ok4, ...res4] = xpcall(foo)
+
+```
+### lua
+```lua
+local ok, res = pcall(foo)
+local ok2, res2 = xpcall(foo)
+local e1, e2 = unpack(bar)
+local ok3, res3
+do
+    local __tmp = pcall2(foo)
+    ok3 = __tmp[1]
+    res3 = __tmp[2]
+end
+local ok4, res4
+do
+    local __tmp = xpcall(foo)
+    ok4 = __tmp[1]
+    res4 = {}
+    for __i = 2, #__tmp do
+        res4[#res4 + 1] = __tmp[__i]
+    end
+end
+
 ```
 ## object
 ### js
diff --git a/package.json b/package.json
index 59e5d20..b10b240 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@xiangnanscu/js2lua",
-  "version": "0.42.0",
+  "version": "0.43.0",
   "type": "module",
   "description": "Writing LuaJIT with the expressiveness of JavaScript.",
   "main": "src/js2lua.mjs",
diff --git a/src/App.vue b/src/App.vue
index 9e6479d..5790f55 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -50,7 +50,7 @@ const luacode = computed(() => {
   return js2lua(jscode.value, selectOptions.value);
 });
 
-const jsast = computed(() => js2ast(jscode.value, selectOptions.value));
+const jsast = computed(() => js2ast(jscode.value, selectOptions.value)?.program.body);
 function copylua() {
   CopyToClipboard("luacode");
 }
diff --git a/src/js2lua.mjs b/src/js2lua.mjs
index 7e6eef2..f91a4fc 100644
--- a/src/js2lua.mjs
+++ b/src/js2lua.mjs
@@ -127,6 +127,37 @@ function hasIdentifier(ast, name, depth) {
   );
   return find;
 }
+const multiReturnFunctions = ['pcall', 'xpcall', 'unpack'];
+function isMultiReturnAssignment(ast) {
+  // 检查是否为赋值语句
+  if (ast.type !== 'VariableDeclaration' || ast.declarations.length !== 1) {
+    return false;
+  }
+
+  const declaration = ast.declarations[0];
+
+  // 检查左边是否为数组解构形式
+  if (declaration.id.type !== 'ArrayPattern') {
+    return false;
+  }
+
+  // 检查数组解构的元素是否全部为标识符
+  if (!declaration.id.elements.every(element => element && element.type === 'Identifier')) {
+    return false;
+  }
+
+  // 检查右边是否为函数调用
+  if (declaration.init?.type !== 'CallExpression') {
+    return false;
+  }
+
+  // 检查函数名是否为Lua的多返回值内置函数
+
+  const calleeName = declaration.init.callee.name;
+
+  return multiReturnFunctions.includes(calleeName);
+}
+
 function renameThisToCls(ast) {
   walkAst(ast, (node) => {
     if (node.type == "ThisExpression") {
@@ -441,6 +472,10 @@ function ast2lua(ast, opts = {}) {
       case "File":
         return joinAst(ast.program.body, ";\n");
       case "VariableDeclaration": {
+        if (isMultiReturnAssignment(ast)) {
+          const declare = ast.declarations[0]
+          return `local ${declare.id.elements.map(_ast2lua).join(", ")} = ${_ast2lua(declare.init)}`;
+        }
         const declarePrefix = ast.noPrefix ? "" : "local ";
         return ast.declarations
           .map(_ast2lua)
diff --git a/src/jsInit.js b/src/jsInit.js
index 0a06ab8..eec2841 100644
--- a/src/jsInit.js
+++ b/src/jsInit.js
@@ -1,3 +1,5 @@
+const { a, b: bAlias, ...rest } = { a: 1, b: 2, c: 3, d: 4 }
+const [x, y, ...others] = [1, 2, 3, 4]
 for (i = 0; i < 10; i = i + 2) {
   if (i % 2) {
     continue;
diff --git a/test/multipleReturnForLuaFunction.mjs b/test/multipleReturnForLuaFunction.mjs
new file mode 100644
index 0000000..d109399
--- /dev/null
+++ b/test/multipleReturnForLuaFunction.mjs
@@ -0,0 +1,6 @@
+let [ok, res] = pcall(foo)
+let [ok2, res2] = xpcall(foo)
+let [e1, e2] = unpack(bar)
+// comparision
+let [ok3, res3] = pcall2(foo)
+let [ok4, ...res4] = xpcall(foo)