sideEffectNodeDetector = $sideEffectNodeDetector; $this->betterNodeFinder = $betterNodeFinder; } public function getRuleDefinition() : RuleDefinition { return new RuleDefinition('Simplify useless double assigns', [new CodeSample(<<<'CODE_SAMPLE' $value = 1; $value = 1; CODE_SAMPLE , '$value = 1;')]); } /** * @return array> */ public function getNodeTypes() : array { return [Foreach_::class, FileWithoutNamespace::class, ClassMethod::class, Function_::class, Closure::class, If_::class, Namespace_::class]; } /** * @param Foreach_|FileWithoutNamespace|If_|Namespace_|ClassMethod|Function_|Closure $node */ public function refactorWithScope(Node $node, Scope $scope) : ?Node { $stmts = $node->stmts; if ($stmts === null) { return null; } $hasChanged = \false; foreach ($stmts as $key => $stmt) { if (!isset($stmts[$key + 1])) { continue; } if (!$stmt instanceof Expression) { continue; } $nextStmt = $stmts[$key + 1]; if (!$nextStmt instanceof Expression) { continue; } if (!$stmt->expr instanceof Assign) { continue; } if (!$nextStmt->expr instanceof Assign) { continue; } $nextAssign = $nextStmt->expr; if (!$this->nodeComparator->areNodesEqual($nextAssign->var, $stmt->expr->var)) { continue; } // early check self referencing, ensure that variable not re-used if ($this->isSelfReferencing($nextAssign)) { continue; } // detect call expression has side effect // no calls on right, could hide e.g. array_pop()|array_shift() if ($this->sideEffectNodeDetector->detectCallExpr($stmt->expr->expr, $scope)) { continue; } if (!$stmt->expr->var instanceof Variable && !$stmt->expr->var instanceof PropertyFetch && !$stmt->expr->var instanceof StaticPropertyFetch) { continue; } // remove current Stmt if will be overriden in next stmt unset($node->stmts[$key]); $hasChanged = \true; } if (!$hasChanged) { return null; } return $node; } private function isSelfReferencing(Assign $assign) : bool { return (bool) $this->betterNodeFinder->findFirst($assign->expr, function (Node $subNode) use($assign) : bool { return $this->nodeComparator->areNodesEqual($assign->var, $subNode); }); } }