4.0 | File::addMessage(): do not ignore Internal errors when scanning selectively

[jrfnl]

Description

Recreation of upstream PR squizlabs/PHP_CodeSniffer#3915 + rebased against the 4.0 branch:

ErrorSuppressionTest: prevent Internal errors

... about a mismatch in line endings when the code "template" is defined using a heredoc with Linux line endings, while the code snippets being inserted into the code "template" were using line endings matching the OS on which the tests were being run.

File::addMessage(): do not ignore Internal errors when scanning selectively

When either the --sniffs=... CLI parameter is used, or the --exclude=... CLI parameter, the File::addMessage() method bows out when an error is passed which is not for one of the selected sniffs/is for one of the excluded sniffs.

Unfortunately, this "bowing out" did not take Internal errors into account, meaning those were now hidden, while those - IMO - should always be thrown as they generally inform the end-user of something wrong with the file which impacts the scan results (mixed line endings/no code found etc).

Fixed now.

Includes updating two test files to allow for seeing internal errors.

👉🏻 This could be considered a breaking change, though I'm not sure whether it should be. Opinions welcome.

Most typically, this change may impact tests for external standards which don't expect Internal errors.

👆🏻 Note: I've decided to err on the side of caution and have moved this PR to the 4.0 branch now.

Suggested changelog entry

Changed:

• Internal errors will no longer be suppressed when the --sniffs CLI argument is used.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
  • This change is only breaking for integrators, not for external standards or end-users.
• Documentation improvement