Printer: remove the separator after a removed first list item

Removing the first type from A|B|C printed |B|C.
Removing the first type from (A & B) printed ( & B).

Amp-Thread-ID: https://ampcode.com/threads/T-01a17930-0285-73c5-a957-4325c77aa1b2

Author: ondrejmirtes

src/Printer/Printer.php

@@ -603,6 +603,7 @@ private function printArrayFormatPreserving(array $nodes, array $originalNodes,
 		$insertStr = $this->listInsertionMap[$mapKey] ?? null;
 		$result = '';
 		$beforeFirstKeepOrReplace = true;
+		$skipRemovedNode = false;
 		$delayedAdd = [];
 
 		$insertNewline = false;
@@ -643,7 +644,12 @@ private function printArrayFormatPreserving(array $nodes, array $originalNodes,
 				$commentStartPos = count($origComments) > 0 ? $origComments[0]->startIndex : $itemStartPos;
 				assert($commentStartPos >= 0);
 
-				$result .= $originalTokens->getContentBetween($tokenIndex, $itemStartPos);
+				if ($skipRemovedNode) {
+					// the separator after the removed first item belongs to it
+					$skipRemovedNode = false;
+				} else {
+					$result .= $originalTokens->getContentBetween($tokenIndex, $itemStartPos);
+				}
 
 				if (count($delayedAdd) > 0) {
 					foreach ($delayedAdd as $delayedAddNode) {
@@ -760,12 +766,18 @@ private function printArrayFormatPreserving(array $nodes, array $originalNodes,
 				if ($i === 0) {
 					// If we're removing from the start, keep the tokens before the node and drop those after it,
 					// instead of the other way around.
-					$originalTokensArray = $originalTokens->getTokens();
-					for ($j = $tokenIndex; $j < $itemStartPos; $j++) {
-						if ($originalTokensArray[$j][Lexer::TYPE_OFFSET] === Lexer::TOKEN_PHPDOC_EOL) {
-							break;
+					if ($mapKey === PhpDocNode::class . '->children') {
+						// the line of the removed child is dropped, the next child keeps its own line
+						$originalTokensArray = $originalTokens->getTokens();
+						for ($j = $tokenIndex; $j < $itemStartPos; $j++) {
+							if ($originalTokensArray[$j][Lexer::TYPE_OFFSET] === Lexer::TOKEN_PHPDOC_EOL) {
+								break;
+							}
+							$result .= $originalTokensArray[$j][Lexer::VALUE_OFFSET];
 						}
-						$result .= $originalTokensArray[$j][Lexer::VALUE_OFFSET];
+					} else {
+						$result .= $originalTokens->getContentBetween($tokenIndex, $itemStartPos);
+						$skipRemovedNode = true;
 					}
 				}
 

tests/PHPStan/Printer/PrinterTest.php

@@ -58,6 +58,7 @@
 use PHPUnit\Framework\TestCase;
 use function array_map;
 use function array_pop;
+use function array_shift;
 use function array_slice;
 use function array_splice;
 use function array_unshift;
@@ -2850,6 +2851,54 @@ public function enterNode(Node $node)
 				 */'),
 			$addCommentToObjectShapeItemMiddle,
 		];
+
+		$removeFirstType = new class extends AbstractNodeVisitor {
+
+			public function enterNode(Node $node)
+			{
+				if ($node instanceof UnionTypeNode || $node instanceof IntersectionTypeNode) {
+					array_shift($node->types);
+				}
+
+				return $node;
+			}
+
+		};
+
+		yield [
+			'/** @var A|B|C */',
+			'/** @var B|C */',
+			$removeFirstType,
+		];
+
+		yield [
+			'/** @var A | B | C */',
+			'/** @var B | C */',
+			$removeFirstType,
+		];
+
+		yield [
+			'/** @var (A & B & C) */',
+			'/** @var (B & C) */',
+			$removeFirstType,
+		];
+
+		yield [
+			'/** @var A|B|C|D */',
+			'/** @var C|D */',
+			new class extends AbstractNodeVisitor {
+
+				public function enterNode(Node $node)
+				{
+					if ($node instanceof UnionTypeNode) {
+						$node->types = [$node->types[2], $node->types[3]];
+					}
+
+					return $node;
+				}
+
+			},
+		];
 	}
 
 	/**