Fix conditional types

Author: rvanvelzen

src/Type/ConditionalType.php

@@ -113,19 +113,17 @@ protected function getResult(): Type
 	{
 		$isSuperType = $this->target->isSuperTypeOf($this->subject);
 
-		$yesType = fn () => TypeTraverser::map(!$this->negated ? $this->if : $this->else, function (Type $type, callable $traverse) {
-			if ($type->equals($this->subject)) {
-				return !$this->negated ? TypeCombinator::intersect($type, $this->target) : TypeCombinator::remove($type, $this->target);
-			}
-			return $traverse($type);
-		});
-
-		$noType = fn () => TypeTraverser::map(!$this->negated ? $this->else : $this->if, function (Type $type, callable $traverse) {
-			if ($type->equals($this->subject)) {
-				return !$this->negated ? TypeCombinator::remove($type, $this->target) : TypeCombinator::intersect($type, $this->target);
-			}
-			return $traverse($type);
-		});
+		$intersectedType = TypeCombinator::intersect($this->subject, $this->target);
+		$removedType = TypeCombinator::remove($this->subject, $this->target);
+
+		$yesType = fn () => TypeTraverser::map(
+			!$this->negated ? $this->if : $this->else,
+			fn (Type $type, callable $traverse) => $type === $this->subject ? (!$this->negated ? $intersectedType : $removedType) : $traverse($type),
+		);
+		$noType = fn () => TypeTraverser::map(
+			!$this->negated ? $this->else : $this->if,
+			fn (Type $type, callable $traverse) => $type === $this->subject ? (!$this->negated ? $removedType : $intersectedType) : $traverse($type),
+		);
 
 		if ($isSuperType->yes()) {
 			return $yesType();

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1351,6 +1351,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8517.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Functions/data/bug-9803.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/impure-connection-fns.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-9963.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/bug-9963.php

@@ -0,0 +1,23 @@
+<?php declare(strict_types = 1);
+
+namespace Bug9963;
+
+use function PHPStan\Testing\assertType;
+
+class HelloWorld
+{
+    /**
+     * @param int|int[]       $id
+     *
+     * @return ($id is array ? static[] : static|false)
+     */
+    final public function find($id)
+    {
+		return [];
+	}
+}
+
+function ($something) {
+	$h = new HelloWorld();
+	assertType('array<Bug9963\HelloWorld>|Bug9963\HelloWorld|false', $h->find($something));
+};

tests/PHPStan/Rules/Methods/CallMethodsRuleTest.php

@@ -3048,4 +3048,22 @@ public function testObjectShapes(): void
 		]);
 	}
 
+	public function testBug9951(): void
+	{
+		$this->checkThisOnly = false;
+		$this->checkNullables = true;
+		$this->checkUnionTypes = true;
+		$this->checkExplicitMixed = true;
+		$this->analyse([__DIR__ . '/data/bug-9951.php'], [
+			[
+				'Parameter #1 $field of method Bug9951\Cl::addCondition() expects array<int, Bug9951\AbstractScope|Bug9951\Expressionable>|Bug9951\AbstractScope|Bug9951\Expressionable|string, mixed given.',
+				26,
+			],
+			[
+				'Parameter #1 $field of method Bug9951\Cl::addCondition() expects array<int, Bug9951\AbstractScope|Bug9951\Expressionable>|Bug9951\AbstractScope|Bug9951\Expressionable|string, object|string|null given.',
+				31,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Methods/data/bug-9951.php

@@ -0,0 +1,33 @@
+<?php declare(strict_types = 1);
+
+namespace Bug9951;
+
+class AbstractScope {}
+class Expressionable {}
+
+class Cl
+{
+    /**
+     * @param AbstractScope|array<int, AbstractScope|Expressionable>|string|Expressionable $field
+     * @param ($field is string|Expressionable ? ($value is null ? mixed : string) : never) $operator
+     * @param ($operator is string ? mixed : never) $value
+     */
+    public function addCondition($field, $operator = null, $value = null): void
+    {
+	}
+
+	public function testStr(string $field, bool $value): void
+	{
+		$this->addCondition($field, $value);
+	}
+
+	public function testMixed(mixed $field, bool $value): void
+	{
+		$this->addCondition($field, $value);
+	}
+
+	public function testMixedAsUnion(string|object|null $field, bool $value): void
+	{
+		$this->addCondition($field, $value);
+	}
+}