remove artificial case of passing literal null to isNull

Author: staabm

src/Rules/PHPUnit/AssertEmptyIsDiscouragedRule.php

@@ -92,9 +92,6 @@ private function getReplacement(Type $type, bool $negated): ?array
 		if ($type->isInteger()->yes()) {
 			return [$negated ? 'assertNotSame' : 'assertSame', new Int_(0)];
 		}
-		if ($type->isNull()->yes()) {
-			return [$negated ? 'assertNotNull' : 'assertNull', null];
-		}
 		if ($type->isNonFalsyString()->yes()) {
 			return [$negated ? 'assertNotSame' : 'assertSame', new String_('')];
 		}

tests/Rules/PHPUnit/data/assert-empty-is-discouraged-fixable.php

@@ -34,8 +34,6 @@ public function test(
 		$this->assertNotEmpty($integer);
 		Assert::assertEmpty($float);
 		Assert::assertNotEmpty($float);
-		static::assertEmpty(null);
-		static::assertNotEmpty(null);
 		$this->assertEmpty($nonFalsyString);
 		$this->assertNotEmpty($otherNonFalsyString);
 		$this->assertEmpty($string);

tests/Rules/PHPUnit/data/assert-empty-is-discouraged-fixable.php.fixed

@@ -34,8 +34,6 @@ final class AssertEmptyTest extends TestCase
 		$this->assertNotSame(0, $integer);
 		Assert::assertEmpty($float);
 		Assert::assertNotEmpty($float);
-		static::assertNull(null);
-		static::assertNotNull(null);
 		$this->assertSame('', $nonFalsyString);
 		$this->assertNotSame('', $otherNonFalsyString);
 		$this->assertEmpty($string);