Printer: support lists with gaps in keys

src/Printer/Printer.php

@@ -69,6 +69,7 @@
 use PHPStan\PhpDocParser\Parser\TokenIterator;
 use function array_keys;
 use function array_map;
+use function array_values;
 use function assert;
 use function count;
 use function get_class;
@@ -598,6 +599,10 @@ private function printConstExpr(ConstExprNode $node): string
 	 */
 	private function printArrayFormatPreserving(array $nodes, array $originalNodes, TokenIterator $originalTokens, int &$tokenIndex, string $parentNodeClass, string $subNodeName): ?string
 	{
+		// unset() leaves gaps in the keys, the differ reads the lists by position
+		$nodes = array_values($nodes);
+		$originalNodes = array_values($originalNodes);
+
 		$diff = $this->differ->diffWithReplacements($originalNodes, $nodes);
 		$mapKey = $parentNodeClass . '->' . $subNodeName;
 		$insertStr = $this->listInsertionMap[$mapKey] ?? null;

tests/PHPStan/Printer/PrinterTest.php

@@ -2899,6 +2899,44 @@ public function enterNode(Node $node)
 
 			},
 		];
+
+		$unsetSecond = new class extends AbstractNodeVisitor {
+
+			public function enterNode(Node $node)
+			{
+				if ($node instanceof PhpDocNode) {
+					unset($node->children[1]);
+				}
+
+				if ($node instanceof UnionTypeNode) {
+					unset($node->types[1]);
+				}
+
+				return $node;
+			}
+
+		};
+
+		yield [
+			'/** @var A|B|C */',
+			'/** @var A|C */',
+			$unsetSecond,
+		];
+
+		yield [
+			self::nowdoc('
+			/**
+			 * @param Foo $foo
+			 * @param Bar $bar
+			 * @param Baz $baz
+			 */'),
+			self::nowdoc('
+			/**
+			 * @param Foo $foo
+			 * @param Baz $baz
+			 */'),
+			$unsetSecond,
+		];
 	}
 
 	/**
@@ -2941,6 +2979,15 @@ public function enterNode(Node $node)
 				$node->setAttribute(Attribute::ORIGINAL_NODE, null);
 				$node->setAttribute(Attribute::COMMENTS, null);
 
+				// the printed result is compared with a node that can have gaps in its lists
+				if ($node instanceof PhpDocNode) {
+					$node->children = array_values($node->children);
+				}
+
+				if ($node instanceof UnionTypeNode) {
+					$node->types = array_values($node->types);
+				}
+
 				return $node;
 			}