DuplicateKeysInLiteralArraysRule: Fixed union type handling

Author: staabm

src/Rules/Arrays/DuplicateKeysInLiteralArraysRule.php

@@ -9,6 +9,7 @@
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
 use PHPStan\Type\Constant\ConstantIntegerType;
+use PHPStan\Type\TypeCombinator;
 use function array_keys;
 use function count;
 use function implode;
@@ -49,6 +50,7 @@ public function processNode(Node $node, Scope $scope): array
 		 * - False means a non-scalar value was encountered and we cannot be sure of the next keys.
 		 */
 		$autoGeneratedIndex = null;
+		$overallKeyType = null;
 		foreach ($node->getItemNodes() as $itemNode) {
 			$item = $itemNode->getArrayItem();
 			if ($item === null) {
@@ -75,6 +77,8 @@ public function processNode(Node $node, Scope $scope): array
 					$autoGeneratedIndex = $autoGeneratedIndex === null
 						? $arrayKeyValues[0]
 						: max($autoGeneratedIndex, $arrayKeyValues[0]);
+				} elseif (count($arrayKeyValues) > 1) {
+					$autoGeneratedIndex = false;
 				}
 			}
 
@@ -84,6 +88,14 @@ public function processNode(Node $node, Scope $scope): array
 				continue;
 			}
 
+			if ($overallKeyType === null) {
+				$duplicate = false;
+				$overallKeyType = $keyType;
+			} else {
+				$duplicate = $overallKeyType->isSuperTypeOf($keyType)->yes();
+				$overallKeyType = TypeCombinator::union($overallKeyType, $keyType);
+			}
+
 			foreach ($keyValues as $value) {
 				$printedValue = $key !== null
 					? $this->exprPrinter->printExpr($key)
@@ -94,9 +106,7 @@ public function processNode(Node $node, Scope $scope): array
 					$valueLines[$value] = $item->getStartLine();
 				}
 
-				$previousCount = count($values);
-				$values[$value] = $printedValue;
-				if ($previousCount !== count($values)) {
+				if (!$duplicate) {
 					continue;
 				}
 

tests/PHPStan/Rules/Arrays/DuplicateKeysInLiteralArraysRuleTest.php

@@ -73,6 +73,10 @@ public function testDuplicateKeys(): void
 				'Array has 2 duplicate keys with value \'key\' (\'key\', $key2).',
 				105,
 			],
+			[
+				"Array has 2 duplicate keys with value 'bar' (\$key, 'bar').",
+				128,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Arrays/data/duplicate-keys.php

@@ -107,4 +107,27 @@ public function doUnionKeys(string $key): void
 		];
 	}
 
+	/**
+	 * @param 'foo'|'bar' $key
+	 */
+	public function maybeDuplicate(string $key): void
+	{
+		$a = [
+			'foo' => 'foo',
+			$key => 'foo|bar',
+		];
+	}
+
+	/**
+	 * @param 'foo'|'bar' $key
+	 */
+	public function sureDuplicate(string $key): void
+	{
+		$a = [
+			'foo' => 'foo',
+			$key => 'foo|bar',
+			'bar' => 'bar',
+		];
+	}
+
 }