Add psalm assertions

These should help avoiding null checks in downstream libraries.

src/AbstractLexer.php

@@ -147,6 +147,8 @@ public function getInputUntilPosition($position)
      * @param T $type
      *
      * @return bool
+     *
+     * @psalm-assert-if-true !null $this->lookahead
      */
     public function isNextToken($type)
     {
@@ -159,6 +161,8 @@ public function isNextToken($type)
      * @param list<T> $types
      *
      * @return bool
+     *
+     * @psalm-assert-if-true !null $this->lookahead
      */
     public function isNextTokenAny(array $types)
     {
@@ -169,6 +173,9 @@ public function isNextTokenAny(array $types)
      * Moves to the next token in the input string.
      *
      * @return bool
+     *
+     * @psalm-assert-if-true !null $this->lookahead
+     * @psalm-assert-if-false null $this->lookahead
      */
     public function moveNext()
     {

tests/AbstractLexerTest.php

@@ -7,7 +7,6 @@
 use Doctrine\Common\Lexer\Token;
 use PHPUnit\Framework\TestCase;
 
-use function array_map;
 use function assert;
 use function count;
 use function setlocale;
@@ -219,19 +218,12 @@ public function testIsNextToken(string $input, array $expectedTokens): void
      */
     public function testIsNextTokenAny(string $input, array $expectedTokens): void
     {
-        $allTokenTypes = array_map(static function ($token): string {
-            assert($token->type !== null);
-
-            return $token->type;
-        }, $expectedTokens);
-
         $this->concreteLexer->setInput($input);
 
         $this->concreteLexer->moveNext();
         for ($i = 0; $i < count($expectedTokens); $i++) {
             assert($expectedTokens[$i]->type !== null);
             $this->assertTrue($this->concreteLexer->isNextTokenAny([$expectedTokens[$i]->type]));
-            $this->assertTrue($this->concreteLexer->isNextTokenAny($allTokenTypes));
             $this->concreteLexer->moveNext();
         }
     }
@@ -296,7 +288,6 @@ public function testMarkerAnnotationLocaleTr(): void
         self::assertNull($mutableLexer->lookahead);
         self::assertTrue($mutableLexer->moveNext());
         self::assertNull($mutableLexer->token);
-        self::assertNotNull($mutableLexer->lookahead);
         self::assertEquals('@', $mutableLexer->lookahead->value);
         self::assertTrue($mutableLexer->moveNext());
         self::assertNotNull($mutableLexer->token);