Per-file batch fixing for --fix option

src/Analyser/Error.php

@@ -261,6 +261,27 @@ public function getFixedErrorDiff(): ?FixedErrorDiff
 		return $this->fixedErrorDiff;
 	}
 
+	/**
+	 * @internal Experimental
+	 */
+	public function withFixedErrorDiff(FixedErrorDiff $fixedErrorDiff): self
+	{
+		return new self(
+			$this->message,
+			$this->file,
+			$this->line,
+			$this->canBeIgnored,
+			$this->filePath,
+			$this->traitFilePath,
+			$this->tip,
+			$this->nodeLine,
+			$this->nodeType,
+			$this->identifier,
+			$this->metadata,
+			$fixedErrorDiff,
+		);
+	}
+
 	/**
 	 * @return mixed
 	 */

src/Analyser/FileAnalyserCallback.php

@@ -17,6 +17,7 @@
 use PHPStan\Rules\Registry as RuleRegistry;
 use function array_keys;
 use function get_class;
+use function spl_object_id;
 use function sprintf;
 
 /**
@@ -45,6 +46,9 @@ final class FileAnalyserCallback
 	/** @var list<Error> */
 	private array $temporaryFileErrors = [];
 
+	/** @var array<string, list<PendingFix>> */
+	private array $pendingFixesByFile = [];
+
 	/** @var LinesToIgnore */
 	private array $linesToIgnore;
 
@@ -77,8 +81,6 @@ public function __construct(
 
 	public function __invoke(Node $node, Scope $scope): void
 	{
-		$parserNodes = $this->parserNodes;
-
 		/** @var Scope&NodeCallbackInvoker $scope */
 		if ($node instanceof Node\Stmt\Trait_) {
 			foreach (array_keys($this->linesToIgnore[$this->file] ?? []) as $lineToIgnore) {
@@ -101,14 +103,6 @@ public function __invoke(Node $node, Scope $scope): void
 			}
 		}
 
-		if ($scope->isInTrait()) {
-			$traitReflection = $scope->getTraitReflection();
-			if ($traitReflection->getFileName() !== null) {
-				$traitFilePath = $traitReflection->getFileName();
-				$parserNodes = $this->parser->parseFile($traitFilePath);
-			}
-		}
-
 		if ($this->outerNodeCallback !== null) {
 			($this->outerNodeCallback)($node, $scope);
 		}
@@ -149,7 +143,7 @@ public function __invoke(Node $node, Scope $scope): void
 			}
 
 			foreach ($ruleErrors as $ruleError) {
-				$error = $this->ruleErrorTransformer->transform($ruleError, $scope, $parserNodes, $node);
+				[$error, $pendingFix] = $this->ruleErrorTransformer->transformPreserveFixable($ruleError, $scope, $node);
 
 				if ($error->canBeIgnored()) {
 					foreach ($this->ignoreErrorExtensions as $ignoreErrorExtension) {
@@ -160,6 +154,11 @@ public function __invoke(Node $node, Scope $scope): void
 				}
 
 				$this->temporaryFileErrors[] = $error;
+				if ($pendingFix === null) {
+					continue;
+				}
+
+				$this->pendingFixesByFile[$pendingFix->fixingFilePath][] = $pendingFix;
 			}
 		}
 
@@ -305,7 +304,34 @@ public function getUnmatchedLineIgnores(): array
 	 */
 	public function getTemporaryFileErrors(): array
 	{
-		return $this->temporaryFileErrors;
+		if ($this->pendingFixesByFile === []) {
+			return $this->temporaryFileErrors;
+		}
+
+		$parserNodesByFile = [$this->file => $this->parserNodes];
+		foreach (array_keys($this->pendingFixesByFile) as $fixingFilePath) {
+			if (isset($parserNodesByFile[$fixingFilePath])) {
+				continue;
+			}
+			$parserNodesByFile[$fixingFilePath] = $this->parser->parseFile($fixingFilePath);
+		}
+
+		$diffsByErrorId = $this->ruleErrorTransformer->finalizePendingFixes(
+			$this->pendingFixesByFile,
+			$parserNodesByFile,
+		);
+
+		if ($diffsByErrorId === []) {
+			return $this->temporaryFileErrors;
+		}
+
+		$finalErrors = [];
+		foreach ($this->temporaryFileErrors as $error) {
+			$diff = $diffsByErrorId[spl_object_id($error)] ?? null;
+			$finalErrors[] = $diff !== null ? $error->withFixedErrorDiff($diff) : $error;
+		}
+
+		return $finalErrors;
 	}
 
 	/**

src/Analyser/PendingFix.php

@@ -0,0 +1,26 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Analyser;
+
+use Closure;
+use PhpParser\Node;
+
+/**
+ * @internal
+ */
+final class PendingFix
+{
+
+	/**
+	 * @param Closure(Node): Node $newNodeCallable
+	 */
+	public function __construct(
+		public readonly Error $error,
+		public readonly Node $originalNode,
+		public readonly Closure $newNodeCallable,
+		public readonly string $fixingFilePath,
+	)
+	{
+	}
+
+}