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);
});
}
}