Normalize leading backslashes in banned function names

[spawnia]

I stumbled upon this when trying to ban the use of sprintf in our project. Because we are using the amazing https://github.com/thecodingmachine/safe, we also have to ban \Safe\printf.

The configuration looks like this:

  banned_code:
    nodes:
    - type: Expr_FuncCall
      functions:
      - sprintf
      - \Safe\sprintf

What happened is that \Safe\sprintf was not found. Upon further investigation, i found that php-parser strips leading backslashes from function calls, even when they occur in the source code.

To avoid this hard to find error, i applied the same normalization to the banned functions definitions from the configuration file.

[spawnia]

@mremi do you mind taking a look at this PR?

[spawnia]

@mremi I just resolved the merge conflicts. After 3 years, can I get some feedback?

[szepeviktor]

@celcius112 Do you have someone at Ekino to look at this PR?

[mremi]

Hi @spawnia sorry for the delay, thank you for this contribution 👍 , could you please update CHANGELOG.md and squash your commits?

[spawnia]

Added a changelog entry. Can you just use GitHub's Squash & Merge? I am having a hard time getting git to do what I need it to.

[mremi]

Done, thanks again

[kayw-geek]

From the method name to see if it should not have a return value and there is no need to pass parameters.

[spawnia]

Mutating parameters is neither common nor good practice in PHP and requires passing by reference for array. Seems bad.

[kayw-geek]

Wouldn't the following be better practice?

    public function __construct(array $bannedNodes)
    {
        $this->bannedNodes     = array_column($bannedNodes, null, 'type');
        $this->bannedFunctions = self::normalizeFunctionNames();
    }
  protected function normalizeFunctionNames(): void
    {
        $this->bannedFunctions =  array_map(
            static function (string $function): string {
                return ltrim($function, '\\');
            },
            $this->bannedNodes['Expr_FuncCall']['functions'] ?? []
        );
    }

[spawnia]

I think it would be much worse, the signature (): void expresses no intent.