Psalm flags this condition as redundant:
```
ERROR: RedundantCondition - src/DocBlock/Tags/Return_.php:62:48 - "" can never contain non-empty-lowercase-string (see https://psalm.dev/122)
return $type . ($description !== '' ? ($type !== '' ? ' ' : '') . $description : '');
```
Based on the statement in the line above - `$type = $this->type ? '' . $this->type : 'mixed';` -, Psalm is correct and the `$type` variable can never be an empty string.
Psalm flags these type casts as redundant:
```
ERROR: RedundantCastGivenDocblockType - src/DocBlock/Tags/Author.php:80:23 - Redundant cast to string given docblock-provided type (see https://psalm.dev/263)
$authorName = (string) $this->authorName;
ERROR: RedundantCastGivenDocblockType - src/DocBlock/Tags/Example.php:150:21 - Redundant cast to string given docblock-provided type (see https://psalm.dev/263)
$filePath = (string) $this->filePath;
ERROR: RedundantCastGivenDocblockType - src/DocBlock/Tags/Link.php:74:17 - Redundant cast to string given docblock-provided type (see https://psalm.dev/263)
$link = (string) $this->link;
ERROR: RedundantCastGivenDocblockType - src/DocBlock/Tags/Method.php:228:23 - Redundant cast to string given docblock-provided type (see https://psalm.dev/263)
$methodName = (string) $this->methodName;
```
I have verified each and can confirm that these are redundant. They are probably a left-over from the time when the `__construct()` method in these classes did not yet have type declarations.
Correctly flagged by Psalm:
```
ERROR: PossiblyNullArgument - src\Utils.php:50:53 - Argument 3 of preg_split cannot be null, possibly null value provided (see https://psalm.dev/078)
$parts = php_preg_split($pattern, $subject, $limit, $flags);
```
The `$limit` argument of the PHP native `preg_split()` function is not nullable.
Ref: https://www.php.net/manual/en/function.preg-split
PHPStan flags the code within the `Source::__toString()` method:
```
------ -------------------------------------------------------------------------------------------
Line DocBlock\Tags\Source.php
------ -------------------------------------------------------------------------------------------
111 Result of || is always true.
114 Result of || is always true.
114 Result of || is always true.
------ -------------------------------------------------------------------------------------------
```
I have investigated this and can confirm that these flags are correct.
1. `$this->startingLine` is cast to an integer in the `__construct()` method (line 45) and subsequently cast to a string in `__toString()` (line 105).
This means that it can only ever be a non-empty ("truthy") string or the string '0', so the `$startingLine || $startingLine === '0'` condition used in two places is redundant.
2. `$this->lineCount` is either an integer or `null` after the `__construct()` method (line 46).
In the `__toString()` method, if the `lineCount` is an integer, it is effectively cast to a string by the concatenation with an empty string on line 107, while if the `lineCount` was `null`, it is turned into an empty string.
By changing the concatenation from concatenating with an empty string to concatenating with a one-space string, we can remove the ternary in the `return` statement checking for `$lineCount` being empty.
The existing unit tests already cover this code and still pass after this change.
The See, Covers and Use tags can reference also methods, properties and
constants. Which means that the FqsenResolver cannot handle those properly.
This patch fixes that issue.