Preserve constant array when assigning a union of scalars

ondrejmirtes · ondrejmirtes · commit 2f66c45222c4 · 2026-04-23T19:48:55.000+02:00
diff --git a/src/Type/Constant/ConstantArrayTypeBuilder.php b/src/Type/Constant/ConstantArrayTypeBuilder.php
@@ -286,7 +286,7 @@ public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $opt
 					return;
 				}
 
-				if (!$hasMatch && count($this->keyTypes) > 0) {
+				if (!$hasMatch) {
 					foreach ($scalarTypes as $scalarType) {
 						$this->keyTypes[] = $scalarType;
 						$this->valueTypes[] = $valueType;
diff --git a/tests/PHPStan/Analyser/nsrt/array-change-key-case.php b/tests/PHPStan/Analyser/nsrt/array-change-key-case.php
@@ -78,7 +78,7 @@ public function sayHello(
 		assertType('array{foo: 1, bar?: 2}', array_change_key_case($arr9));
 		assertType('array{foo: 1, bar?: 2}', array_change_key_case($arr9, CASE_LOWER));
 		assertType('array{FOO: 1, BAR?: 2}', array_change_key_case($arr9, CASE_UPPER));
-		assertType("non-empty-array<'BAR'|'bar'|'FOO'|'foo', 1|2>", array_change_key_case($arr9, $case));
+		assertType("non-empty-array{foo?: 1, FOO?: 1, bar?: 2, BAR?: 2}", array_change_key_case($arr9, $case));
 
 		assertType("array<'bar'|'foo', string>", array_change_key_case($arr10));
 		assertType("array<'bar'|'foo', string>", array_change_key_case($arr10, CASE_LOWER));
diff --git a/tests/PHPStan/Analyser/nsrt/bug-13786.php b/tests/PHPStan/Analyser/nsrt/bug-13786.php
@@ -14,10 +14,10 @@
     foreach ($cols as $col) {
         $total[$id][$col] = '0';
     }
-    assertType("non-empty-array<'a'|'b'|'c'|'d', '0'>", $total[$id]);
+    assertType("non-empty-array{a?: '0', b?: '0', c?: '0', d?: '0'}", $total[$id]);
     $total[$id]['d'] = '0';
-    assertType("non-empty-array<'a'|'b'|'c'|'d', '0'>&hasOffsetValue('d', '0')", $total[$id]);
+    assertType("array{a?: '0', b?: '0', c?: '0', d: '0'}", $total[$id]);
 }
 
 $total[$id]['e'] = '1';
-assertType("non-empty-array<'a'|'b'|'c'|'d'|'e', '0'|'1'>&hasOffsetValue('e', '1')", $total[$id]);
+assertType("array{a?: '0', b?: '0', c?: '0', d?: '0', e: '1'}", $total[$id]);
diff --git a/tests/PHPStan/Analyser/nsrt/bug-14333.php b/tests/PHPStan/Analyser/nsrt/bug-14333.php
@@ -83,7 +83,7 @@ function testMultipleScalarKeyValues(bool $key): void
 
 	// $key could be 1 (true) so $b[1] = 3 might also update $a
 	$b[1] = 3;
-	assertType('1|2|3', $a);
+	assertType('2|3', $a);
 }
 
 /** @param 'a'|'b' $key */
diff --git a/tests/PHPStan/Analyser/nsrt/bug-14489.php b/tests/PHPStan/Analyser/nsrt/bug-14489.php
@@ -23,7 +23,7 @@ function () {
 	}
 
 	$values = array_values($cData);
-	assertType('non-empty-list<non-empty-array<0|1, 1|4>>', $values);
+	assertType('list{0?: non-empty-array<0|1, 1|4>, 1?: non-empty-array<0|1, 1|4>}', $values);
 };
 
 function () {
@@ -35,12 +35,12 @@ function () {
 	$cData = [];
 	while (rand(0, 1)) {
 		if (array_key_exists($c, $cData)) {
-			assertType('non-empty-array<\'c1\'|\'c2\', array{1}|array{4}>', $cData);
+			assertType('non-empty-array{c1?: array{1}|array{4}, c2?: array{1}|array{4}}', $cData);
 			assertType('array{1}|array{4}', $cData[$c]);
 			$cData[$c] = $cData[$c];
 		} else {
 			$cData[$c] = $ids;
 		}
 	}
-	assertType('array<\'c1\'|\'c2\', array{1}|array{4}>', $cData);
+	assertType('array{}|array{c1?: array{1}|array{4}, c2?: array{1}|array{4}}', $cData);
 };
diff --git a/tests/PHPStan/Analyser/nsrt/set-union-offset-preserve-constant-array.php b/tests/PHPStan/Analyser/nsrt/set-union-offset-preserve-constant-array.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace SetUnionOffsetPreserveConstantArray;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+
+	public function doFoo(): void
+	{
+		$a = [];
+
+		$k = rand(0, 1) ? 1 : 2;
+		$a[$k] = true;
+		assertType('array{1?: true, 2?: true}', $a);
+	}
+
+}

Original file line number	Diff line number	Diff line change
`@@ -286,7 +286,7 @@ public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $opt`
`286`	`286`	`return;`
`287`	`287`	`}`
`288`	`288`
`289`		`- if (!$hasMatch && count($this->keyTypes) > 0) {`
	`289`	`+ if (!$hasMatch) {`
`290`	`290`	`foreach ($scalarTypes as $scalarType) {`
`291`	`291`	`$this->keyTypes[] = $scalarType;`
`292`	`292`	`$this->valueTypes[] = $valueType;`
Original file line number	Diff line number	Diff line change
`@@ -14,10 +14,10 @@`
`14`	`14`	`foreach ($cols as $col) {`
`15`	`15`	`$total[$id][$col] = '0';`
`16`	`16`	`}`
`17`		`- assertType("non-empty-array<'a'\|'b'\|'c'\|'d', '0'>", $total[$id]);`
	`17`	`+ assertType("non-empty-array{a?: '0', b?: '0', c?: '0', d?: '0'}", $total[$id]);`
`18`	`18`	`$total[$id]['d'] = '0';`
`19`		`- assertType("non-empty-array<'a'\|'b'\|'c'\|'d', '0'>&hasOffsetValue('d', '0')", $total[$id]);`
	`19`	`+ assertType("array{a?: '0', b?: '0', c?: '0', d: '0'}", $total[$id]);`
`20`	`20`	`}`
`21`	`21`
`22`	`22`	`$total[$id]['e'] = '1';`
`23`		`-assertType("non-empty-array<'a'\|'b'\|'c'\|'d'\|'e', '0'\|'1'>&hasOffsetValue('e', '1')", $total[$id]);`
	`23`	`+assertType("array{a?: '0', b?: '0', c?: '0', d?: '0', e: '1'}", $total[$id]);`
Original file line number	Diff line number	Diff line change
`@@ -83,7 +83,7 @@ function testMultipleScalarKeyValues(bool $key): void`
`83`	`83`
`84`	`84`	`// $key could be 1 (true) so $b[1] = 3 might also update $a`
`85`	`85`	`$b[1] = 3;`
`86`		`- assertType('1\|2\|3', $a);`
	`86`	`+ assertType('2\|3', $a);`
`87`	`87`	`}`
`88`	`88`
`89`	`89`	`/** @param 'a'\|'b' $key */`