MismatchingDocblockReturnType array template string

[Nikolay-Ivanchenko]

<?php

/**
 * @template Values of non-empty-array<lowercase-string, string>
 * @template DefaultKey of key-of<Values>
 */
final class SortableListType
{
	/**
	 * @param Values $values
	 * @param DefaultKey $defaultKey
	 */
	public function __construct(
		private readonly array $values,
		private readonly string $defaultKey
	) {
	}

	/** @return DefaultKey */
	public function getDefaultKey(): string
	{
		return $this->defaultKey;
	}

	/** @return Values[DefaultKey] */
	public function getDefaultValue(): string
	{
		return $this->values[$this->defaultKey];
	}
}

//type tests
$a = new SortableListType(["a"=> "1", "b" => "2"], "not-exist-key");
$b = new SortableListType(["a"=> "1", "b" => "2"], "a");
$c = new SortableListType(["a"=> "1", "b" => "2"], "b");

//return type tests
$bKey = $b->getDefaultKey();
$bValue = $b->getDefaultValue();

$cKey = $c->getDefaultKey();
$cValue = $c->getDefaultValue();

https://psalm.dev/r/9277d2b643
https://psalm.dev/r/9578e396b2

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/9277d2b643

<?php

/**
 * @template Values of non-empty-array<lowercase-string, string>
 * @template DefaultKey of key-of<Values>
 */
final class SortableListType
{
	/**
	 * @param Values $values
	 * @param DefaultKey $defaultKey
	 */
	public function __construct(
		private readonly array $values,
		private readonly string $defaultKey
	) {
	}

	/** @return DefaultKey */
	public function getDefaultKey(): string
	{
		return $this->defaultKey;
	}

	/** @return Values[DefaultKey] */
	public function getDefaultValue(): string
	{
		return $this->values[$this->defaultKey];
	}
}

//type tests
$a = new SortableListType(["a"=> "1", "b" => "2"], "not-exist-key");
$b = new SortableListType(["a"=> "1", "b" => "2"], "a");
$c = new SortableListType(["a"=> "1", "b" => "2"], "b");

//return type tests
$bKey = $b->getDefaultKey();
$bValue = $b->getDefaultValue();

$cKey = $c->getDefaultKey();
$cValue = $c->getDefaultValue();

Psalm output (using commit a75d26a):

ERROR: InvalidArgument - 33:52 - Argument 2 of SortableListType::__construct expects 'a'|'b', but 'not-exist-key' provided

INFO: UnusedVariable - 33:1 - $a is never referenced or the value is not used

INFO: UnusedVariable - 38:1 - $bKey is never referenced or the value is not used

INFO: UnusedVariable - 39:1 - $bValue is never referenced or the value is not used

INFO: UnusedVariable - 41:1 - $cKey is never referenced or the value is not used

INFO: UnusedVariable - 42:1 - $cValue is never referenced or the value is not used

ERROR: MismatchingDocblockReturnType - 25:14 - Docblock has incorrect return type 'Values[DefaultKey]', should be 'string'