Tagged unions

src/Type/Constant/ConstantArrayType.php

@@ -1096,12 +1096,18 @@ public function isKeysSupersetOf(self $otherArray): bool
 		}
 
 		$otherKeys = $otherArray->keyTypes;
-		foreach ($this->keyTypes as $keyType) {
+		foreach ($this->keyTypes as $i => $keyType) {
 			foreach ($otherArray->keyTypes as $j => $otherKeyType) {
 				if (!$keyType->equals($otherKeyType)) {
 					continue;
 				}
 
+				$valueType = $this->valueTypes[$i];
+				$otherValueType = $otherArray->valueTypes[$j];
+				if ($valueType->isSuperTypeOf($otherValueType)->no()) {
+					continue;
+				}
+
 				unset($otherKeys[$j]);
 				continue 2;
 			}

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -950,6 +950,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7621-1.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7621-2.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7621-3.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/tagged-unions.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/tagged-unions.php

@@ -0,0 +1,181 @@
+<?php
+
+namespace TaggedUnions;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+
+	/** @param array{A: int}|array{A: string} $foo */
+	public function doFoo(array $foo)
+	{
+		assertType('array{A: int}|array{A: string}', $foo);
+		if (is_int($foo['A'])) {
+			assertType("array{A: int}", $foo);
+			$foo['B'] = 'yo';
+			assertType("array{A: int, B: 'yo'}", $foo);
+		} else {
+			assertType('array{A: string}', $foo);
+		}
+
+		assertType("array{A: int, B: 'yo'}|array{A: string}", $foo);
+	}
+
+	/** @param array{A: int, B: 1}|array{A: string, B: 2} $foo */
+	public function doFoo2(array $foo)
+	{
+		assertType('array{A: int, B: 1}|array{A: string, B: 2}', $foo);
+		if (is_int($foo['A'])) {
+			assertType("array{A: int, B: 1}", $foo);
+		} else {
+			assertType("array{A: string, B: 2}", $foo);
+		}
+
+		assertType('array{A: int, B: 1}|array{A: string, B: 2}', $foo);
+	}
+
+	/** @param array{A: int, B: 1}|array{A: string, C: 1} $foo */
+	public function doFoo3(array $foo)
+	{
+		assertType('array{A: int, B: 1}|array{A: string, C: 1}', $foo);
+		if (is_int($foo['A'])) {
+			assertType("array{A: int, B: 1}", $foo);
+		} else {
+			assertType("array{A: string, C: 1}", $foo);
+		}
+
+		assertType('array{A: int, B: 1}|array{A: string, C: 1}', $foo);
+	}
+
+	/** @param array{A: int, B: 1}|array{A: string, C: 1} $foo */
+	public function doFoo4(array $foo)
+	{
+		assertType('array{A: int, B: 1}|array{A: string, C: 1}', $foo);
+		if (isset($foo['C'])) {
+			assertType("array{A: string, C: 1}", $foo);
+		} else {
+			assertType("array{A: int, B: 1}|array{A: string, C: 1}", $foo); // could be array{A: int, B: 1}
+		}
+
+		assertType('array{A: int, B: 1}|array{A: string, C: 1}', $foo);
+	}
+
+	/**
+	 * @param array{A: int}|array{A: int|string} $foo
+	 * @return void
+	 */
+	public function doBar(array $foo)
+	{
+		assertType('array{A: int|string}', $foo);
+	}
+
+}
+
+/**
+ * @phpstan-type Topping string
+ * @phpstan-type Salsa   string
+ *
+ * @phpstan-type Pizza   array{type: 'pizza', toppings: Topping[]}
+ * @phpstan-type Pasta   array{type: 'pasta', salsa: Salsa}
+ * @phpstan-type Meal    Pizza|Pasta
+ */
+class Test
+{
+	/**
+	 * @param Meal $meal
+	 */
+	function test($meal): void {
+		assertType("array{type: 'pasta', salsa: string}|array{type: 'pizza', toppings: array<string>}", $meal);
+		if ($meal['type'] === 'pizza') {
+			assertType("array{type: 'pizza', toppings: array<string>}", $meal);
+		} else {
+			assertType("array{type: 'pasta', salsa: string}", $meal);
+		}
+		assertType("array{type: 'pasta', salsa: string}|array{type: 'pizza', toppings: array<string>}", $meal);
+	}
+}
+
+class HelloWorld
+{
+	/**
+	 * @return array{updated: true, id: int}|array{updated: false, id: null}
+	 */
+	public function sayHello(): array
+	{
+		return ['updated' => false, 'id' => 5];
+	}
+
+	public function doFoo()
+	{
+		$x = $this->sayHello();
+		assertType("array{updated: false, id: null}|array{updated: true, id: int}", $x);
+		if ($x['updated']) {
+			assertType('array{updated: true, id: int}', $x);
+		}
+	}
+}
+
+/**
+ * @psalm-type A array{tag: 'A', foo: bool}
+ * @psalm-type B array{tag: 'B'}
+ */
+class X {
+	/** @psalm-param A|B $arr */
+	public function ooo(array $arr): void {
+		assertType("array{tag: 'A', foo: bool}|array{tag: 'B'}", $arr);
+		if ($arr['tag'] === 'A') {
+			assertType("array{tag: 'A', foo: bool}", $arr);
+		} else {
+			assertType("array{tag: 'B'}", $arr);
+		}
+		assertType("array{tag: 'A', foo: bool}|array{tag: 'B'}", $arr);
+	}
+}
+
+class TipsFromArnaud
+{
+
+	// https://github.com/phpstan/phpstan/issues/7666#issuecomment-1191563801
+
+	/**
+	 * @param array{a: int}|array{a: int} $a
+	 */
+	public function doFoo(array $a): void
+	{
+		assertType('array{a: int}', $a);
+	}
+
+	/**
+	 * @param array{a: int}|array{a: string} $a
+	 */
+	public function doFoo2(array $a): void
+	{
+		assertType('array{a: int|string}', $a);
+	}
+
+	/**
+	 * @param array{a: int, b: int}|array{a: string, b: string} $a
+	 */
+	public function doFoo3(array $a): void
+	{
+		assertType('array{a: int, b: int}|array{a: string, b: string}', $a);
+	}
+
+	/**
+	 * @param array{a: int, b: string}|array{a: string, b:string} $a
+	 */
+	public function doFoo4(array $a): void
+	{
+		assertType('array{a: int|string, b: string}', $a);
+	}
+
+	/**
+	 * @param array{a: int, b: string, c: string}|array{a: string, b: string, c: string} $a
+	 */
+	public function doFoo5(array $a): void
+	{
+		assertType('array{a: int|string, b: string, c: string}', $a);
+	}
+
+}

tests/PHPStan/Rules/Methods/ReturnTypeRuleTest.php

@@ -712,4 +712,15 @@ public function testBug4117(): void
 		$this->analyse([__DIR__ . '/data/bug-4117.php'], []);
 	}
 
+	public function testTaggedUnions(): void
+	{
+		$this->checkExplicitMixed = true;
+		$this->analyse([__DIR__ . '/data/tagged-unions.php'], [
+			[
+				'Method TaggedUnionReturnCheck\HelloWorld::sayHello() should return array{updated: false, id: null}|array{updated: true, id: int} but returns array{updated: false, id: 5}.',
+				12,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Methods/data/tagged-unions.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace TaggedUnionReturnCheck;
+
+class HelloWorld
+{
+	/**
+	 * @return array{updated: true, id: int}|array{updated: false, id: null}
+	 */
+	public function sayHello(): array
+	{
+		return ['updated' => false, 'id' => 5];
+	}
+}