@inheritdoc - check for misspelling

Let's also make sure that #2858021: fix {inheritdoc} typos is integrated in this issue as well, making sure that the @ sign is included.

The problem is that our coding standards explicitly say we should write it with lower case d. There is a coding standards discussion at #3060580: Allow inheritdoc and inheritDoc? to maybe change that.

Until that is settled I think we should allow both variants in Coder.

Nice, thanks a lot! The approach is not perfect because now it would allow {@InHeRiTdOc}, right? That is a bit ugly, so better we check for the exact casing instead?

1. +++ b/coder_sniffer/Drupal/Test/good/good.php
   @@ -1014,6 +1014,15 @@ class Foo implements FooInterface {
   +  /**
   +   * {@inheritDoc}
   +   *
   +   * Allow "inheritDoc".
   +   *
   +   * @link https://www.drupal.org/project/coder/issues/2939783
   +   */
   +  public function test4() {}
   

   I think this is not a good example because it allows aditional text in the comment. I think {@inheritDoc} should only be used standalone, if you need to modify the comment on a function then you should copy the content from the parent class to make it clear. I know we are not forbidding it in Coder yet, but we should not add more examples that do this.

   Can you replace this with just {@inheritDoc} and nothing else?

2. +++ b/coder_sniffer/DrupalPractice/Test/good/good.php
   @@ -175,4 +175,9 @@ class StrictSchemaEnabled {
   +  /**
   +   * {@inheritDoc}
   +   */
   +  protected $allowCaseInsensitiveInheritDoc = TRUE;
   

   we should not modify the DrupalPractice standard with this change, so this example should also go into the Drupal standard good.php

Can you also file this as pull request against https://github.com/pfrenssen/coder ? Then we see the automated tests run.

Updated the patch and committed it, thanks!