Heredoc containing \n cannot be parsed for indenting

Playground link

Input:

<?php
function foo() {
    $message .= <<<EOT
    Please read this message.\n  We apologize for the inconvenience.
    EOT;
}

Output:

Invalid body indentation level (expecting an indentation at least 4) on line 5

  3 |     $message .= <<<EOT
  4 |     Please read this message.\n  We apologize for the inconvenience.
> 5 |     EOT;
    |    ^
  6 | }
  7 |

Expected:

<?php
function foo() {
    $message .= <<<EOT
    Please read this message.\n  We apologize for the inconvenience.
    EOT;
}

Basically, the \n in the middle of the heredoc appears to confuse either the parser or prettier.

从链接的 Prettier PHP Playground 开始，复现包含字面量 \n 的 heredoc 用例。跟踪解析或缩进验证是否错误地处理了该内容，然后为此示例添加回归测试。完成标准是输入能够在没有缩进错误的情况下成功格式化，并保留预期的 heredoc 输出。