1

是否有我没有看到的逻辑错误/案例？

我正在使用 PHP 语言级别 7.1 和 CLI Interpreter PHP 7.1.8 的 PhpStorm 2017.1

我尝试了以下情况：

  1. User有和有carrinho(DB)和没有carrinho_idrequest
  2. User没有和有carrinho(DB)和没有carrinho_idrequest
  3. carrinho_idrequest没有_user
  4. carrinho_id有错user(not logged)
$user = Auth::guard('api')->user();
if(!(isset($user) && ($carrinho = $user->getCarrinho()) != null)){
    if(!isset($data['carrinho_id']) || (($carrinho = Carrinho::find($data['carrinho_id'])) == null) || ($carrinho->usuario_id != null))
        $carrinho = Carrinho::salvar([]);
    if(isset($user))
        $carrinho->setUsuario($user->id);
}

if($carrinho->addProduto($data)) //"$carrinho" Variable might have not been defined
    return response()->json([
        'carrinho_id' => $carrinho->id
    ]);
return response()->json(['msg' => "O produto já está no seu carrinho"],422);

两种可能的情况

$user存在

if(!(true && ($carrinho = $user->getCarrinho()) != null))

2 两种可能的路径

1 - 有$carrinho

if(!(true && true)) -> !(true && true) -> !(true) -> false -> skip if and load the $carrinho from the user

2 - 没有$carrinho

if(!(true && false)) -> !(true && false) -> !(false) -> true -> Go inside the if and define the $carrinho

第一个里面的代码if总是有一个$carrinho

问题出在第一个if。我怎么知道？因为如果我这样做，警告就会消失。

if(!(isset($user) && ($carrinho = $user->getCarrinho()) != null)){
    if(!isset($data['carrinho_id']) || (($carrinho = Carrinho::find($data['carrinho_id'])) == null) || ($carrinho->usuario_id != null))
        $carrinho = Carrinho::salvar([]);
    if(isset($user))
        $carrinho->setUsuario($user->id);
}else{
    $carrinho = Carrinho::salvar([]);
}
4

3 回答 3

1

您的代码在执行过程中可能有问题，PHPStorm 对此进行了说明。在某些情况下你不会有$carrinho对象，例如，如果$user变量存在

if(!(isset($user) && ($carrinho = $user->getCarrinho()) != null)){
    if(!isset($data['carrinho_id']) || (($carrinho = Carrinho::find($data['carrinho_id'])) == null) || ($carrinho->usuario_id != null))
        $carrinho = Carrinho::salvar([]);
    if(isset($user))
        $carrinho->setUsuario($user->id);
}

并且代码$carrinho->addProduto($data)将失败。

你需要修复它。例如，您可以将代码移动到条件块中

if(!(isset($user) && ($carrinho = $user->getCarrinho()) != null)){
    if(!isset($data['carrinho_id']) || (($carrinho = Carrinho::find($data['carrinho_id'])) == null) || ($carrinho->usuario_id != null)) {
        $carrinho = Carrinho::salvar([]);
    }
    if(isset($user)) {
        carrinho->setUsuario($user->id);
    }
    if($carrinho->addProduto($data)) {
        return response()->json([
            'carrinho_id' => $carrinho->id
        ]);
   }

}

return response()->json(['msg' => "O produto já está no seu carrinho"],422);
于 2020-01-23T14:41:29.190 回答
1

这段代码非常难以阅读，因为您将副作用（赋值）与涉及多个布尔运算符的复杂条件结合在一起。让我们试着把它写成一组离散的操作：

// First condition to be evaluated is isset($user)
$haveUser = isset($user);
// If that condition is false, the && will lazily skip the next part
if ( $haveUser ) {
    // Now we conditionally assign $carrinho ...
    $carrinho = $user->getCarrinho();
    // ... and test its value
    $haveCarrinho = ($carrinho != null);
}
// Having done all that, we combine the two conditions
$haveBoth = $haveUser && $haveCarrinho;
// Now we invert that condition for our if statement
if ( ! $haveBoth ) {
    // We know here that $carrinho has either never been set (because $haveUser was false) ...
    //   ... or it was null (setting $haveCarrinho to false)

    // Line 3 - another if statement to unpack
    $haveIdInData = isset($data['carrinho_id']);
    // If that condition is false, the || will shortcut
    if ( ! $haveIdInData ) {
        $carrinho = Carrinho::salvar([]);
    }
    // If we don't short-cut, the rest of line 3 runs
    else {
        // Try finding it by the ID in $data
        $carrinho = Carrinho::find($data['carrinho_id']);
        // If it's null, we short-cut at the next ||
        if ($carrinho == null) {
            $carrinho = Carrinho::salvar([]);
        }
        else {
            // Else we make the next check
            if ($carrinho->usuario_id != null) {
                $carrinho = Carrinho::salvar([]);
            }
        }
    }

    // On to line 4! Reusing our condition from above, since the state of $user won't have changed
    if ( $haveUser ) {
        // This will give a horrible error if $carrinho is null
        $carrinho->setUsuario($user->id);
    }
}

// We've reached line 5, and expect $carrinho to be set, but we have no guarantee of that at all!

4 行代码就包含了很多逻辑！

稍微整理一下，没有让它像原来的那样神秘，我认为这是等价的：

$carrinho = null;
if ( isset($user) ) {
    // Now we conditionally assign $carrinho ...
    $carrinho = $user->getCarrinho();
}
if ( $carrinho == null ) {
    if ( isset($data['carrinho_id']) ) {
        $carrinho = Carrinho::find($data['carrinho_id']);

        if ($carrinho == null || $carrinho->usuario_id != null) {
            $carrinho = Carrinho::salvar([]);
        }
    }
    if(isset($user)) {
        $carrinho->setUsuario($user->id);
    }
}

现在我们可以看到可能的意图：该Carrinho::salvar行应该是任何其他未定义状态的后备，而不是嵌套在其他条件中。

稍加努力，我们就可以完全消除嵌套条件，从而提供更具可读性的内容，如下所示：

// Initialise variables to a known state
$carrinho = null;
$loadedFromUser = false;
// Try on user object
if ( isset($user) ) {
    $carrinho = $user->getCarrinho();
    $loadedFromUser = ($carrinho != null);
}
// Not found? Try looking up by input data
if ( $carrinho == null && isset($data['carrinho_id']) ) {
    $carrinho = Carrinho::find($data['carrinho_id']);
}
// Discard if it already has a user ID, but wasn't loaded from user
if (!$loadedFromUser && $carrinho != null && $carrinho->usuario_id != null) {
    $carrinho = null;
}
// Still not found? Create an empty one
if ($carrinho == null) {
    $carrinho = Carrinho::salvar([]);
}

// Now we know we have an object some way or another, and can assign a user ID to it
if(isset($user) && !$loadedFromUser) {
    $carrinho->setUsuario($user->id);
}

其中一些条件可能并不完全符合预期，但通过将它们分开，我们现在可以更轻松地遵循逻辑并进行适当的更改。

于 2020-01-23T18:29:38.553 回答
0

经过一些质疑和研究，我得出的结论是，硬代码对任何人都没有帮助，在团队合作和项目发展方面。我决定通过以下方式实现代码：

$user = Auth::guard('api')->user();
$hasUser = isset($user);
if($hasUser)
    $carrinho = $user->getCarrinho();
if(!isset($carrinho)){
    if(isset($data['carrinho_id']))
        $carrinho = Carrinho::find($data['carrinho_id']);
    if(!isset($carrinho) || $carrinho->usuario_id != null)
        $carrinho = Carrinho::salvar([]);
    if($hasUser)
        $carrinho->setUsuario($user->id);
}
if($carrinho->addProduto($data))
    return response()->json([
        'carrinho_id' => $carrinho->id
    ]);
return response()->json(['msg' => "O produto já está no seu carrinho"],422);

我不会接受这个答案，因为我仍然不相信代码有错误，因为没有人能找到任何错误。但我将把它留在这里以表明硬代码没有帮助。

于 2020-01-24T19:26:19.197 回答