[SOLID] Add ChangeIfElseValueAssignToEarlyReturnRector

BACKERS.md

@@ -9,13 +9,17 @@ Development of Rector is made possible thanks to these awesome backers! Would yo
 
 Check out all the tiers - higher ones include additional goodies like placing the logo of your company in Rector's README or creating custom set for your needs.
 
-- Jan Votruba
-- Sebastian Schreiber
+- 11com7
+- Alexander Schnitzler
+- Arnaud TIERANT
 - Attila Fulop
 - Jakob Oberhummer
 - Jan Kuchař
+- Jan Votruba
 - Jan Mikes
-- Arnaud TIERANT
+- Ruud Boon
+- thechris
+- Toby
 
 **Thank you for making this happen.**
 
@@ -25,5 +29,6 @@ Check out all the tiers - higher ones include additional goodies like placing th
 
 - Musement S.p.a.
 - Sebastian Schreiber
+- John Linhart
 
 <!-- source: https://www.patreon.com/manageRewardsList -->

packages/SOLID/src/Rector/If_/ChangeIfElseValueAssignToEarlyReturnRector.php

@@ -0,0 +1,127 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\SOLID\Rector\If_;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Stmt\If_;
+use PhpParser\Node\Stmt\Return_;
+use Rector\NodeTypeResolver\Node\AttributeKey;
+use Rector\PhpParser\Node\Manipulator\IfManipulator;
+use Rector\PhpParser\Node\Manipulator\StmtsManipulator;
+use Rector\Rector\AbstractRector;
+use Rector\RectorDefinition\CodeSample;
+use Rector\RectorDefinition\RectorDefinition;
+
+/**
+ * @see https://engineering.helpscout.com/reducing-complexity-with-guard-clauses-in-php-and-javascript-74600fd865c7
+ *
+ * @see \Rector\SOLID\Tests\Rector\If_\ChangeIfElseValueAssignToEarlyReturnRector\ChangeIfElseValueAssignToEarlyReturnRectorTest
+ */
+final class ChangeIfElseValueAssignToEarlyReturnRector extends AbstractRector
+{
+    /**
+     * @var IfManipulator
+     */
+    private $ifManipulator;
+
+    /**
+     * @var StmtsManipulator
+     */
+    private $stmtsManipulator;
+
+    public function __construct(IfManipulator $ifManipulator, StmtsManipulator $stmtsManipulator)
+    {
+        $this->ifManipulator = $ifManipulator;
+        $this->stmtsManipulator = $stmtsManipulator;
+    }
+
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Change if/else value to early return', [
+            new CodeSample(
+                <<<'PHP'
+class SomeClass
+{
+    public function run()
+    {
+        if ($this->hasDocBlock($tokens, $index)) {
+            $docToken = $tokens[$this->getDocBlockIndex($tokens, $index)];
+        } else {
+            $docToken = null;
+        }
+
+        return $docToken;
+    }
+}
+PHP
+,
+                <<<'PHP'
+class SomeClass
+{
+    public function run()
+    {
+        if ($this->hasDocBlock($tokens, $index)) {
+            return $tokens[$this->getDocBlockIndex($tokens, $index)];
+        }
+        return null;
+    }
+}
+PHP
+
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [If_::class];
+    }
+
+    /**
+     * @param If_ $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        $nextNode = $node->getAttribute(AttributeKey::NEXT_NODE);
+        if (! $nextNode instanceof Return_) {
+            return null;
+        }
+
+        if ($nextNode->expr === null) {
+            return null;
+        }
+
+        if (! $this->ifManipulator->isIfAndElseWithSameVariableAssignAsLastStmts($node, $nextNode->expr)) {
+            return null;
+        }
+
+        /** @var Assign $assign */
+        $assign = $this->stmtsManipulator->getUnwrappedLastStmt($node->stmts);
+
+        $lastIfStmtKey = array_key_last($node->stmts);
+        $node->stmts[$lastIfStmtKey] = new Return_($assign->expr);
+
+        /** @var Assign $assign */
+        $assign = $this->stmtsManipulator->getUnwrappedLastStmt($node->else->stmts);
+        $lastElseStmtKey = array_key_last($node->else->stmts);
+
+        $elseStmts = $node->else->stmts;
+        $elseStmts[$lastElseStmtKey] = new Return_($assign->expr);
+
+        $node->else = null;
+
+        foreach ($elseStmts as $elseStmt) {
+            $this->addNodeAfterNode($elseStmt, $node);
+        }
+
+        $this->removeNode($nextNode);
+
+        return $node;
+    }
+}

packages/SOLID/src/Rector/If_/ChangeNestedIfsToEarlyReturnRector.php

@@ -5,10 +5,11 @@ declare(strict_types=1);
 namespace Rector\SOLID\Rector\If_;
 
 use PhpParser\Node;
+use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\BinaryOp;
+use PhpParser\Node\Expr\BooleanNot;
 use PhpParser\Node\Stmt\If_;
 use PhpParser\Node\Stmt\Return_;
-use Rector\Exception\NotImplementedException;
 use Rector\NodeTypeResolver\Node\AttributeKey;
 use Rector\PhpParser\Node\Manipulator\BinaryOpManipulator;
 use Rector\PhpParser\Node\Manipulator\IfManipulator;
@@ -123,20 +124,50 @@ PHP
             if ($nestedIfsWithOnlyReturnCount === $key + 1) {
                 $this->addNodeAfterNode($nestedIfWithOnlyReturn, $if);
             } else {
-                if (! $nestedIfWithOnlyReturn->cond instanceof BinaryOp) {
-                    throw new NotImplementedException(__METHOD__);
-                }
-
-                $inversedCondition = $this->binaryOpManipulator->inverseCondition($nestedIfWithOnlyReturn->cond);
-                if ($inversedCondition === null) {
-                    throw new NotImplementedException(__METHOD__);
-                }
-
-                $nestedIfWithOnlyReturn->cond = $inversedCondition;
-                $nestedIfWithOnlyReturn->stmts = [clone $nextReturn];
-
-                $this->addNodeAfterNode($nestedIfWithOnlyReturn, $if);
+                $this->addStandaloneIfsWithReturn($nestedIfWithOnlyReturn, $if, $nextReturn);
             }
         }
     }
+
+    private function createInvertedCondition(Expr $expr): Expr
+    {
+        // inverse condition
+        if ($expr instanceof BinaryOp) {
+            $inversedCondition = $this->binaryOpManipulator->invertCondition($expr);
+            if ($inversedCondition === null) {
+                return new BooleanNot($expr);
+            }
+
+            return $inversedCondition;
+        }
+
+        return new BooleanNot($expr);
+    }
+
+    private function addStandaloneIfsWithReturn(If_ $nestedIfWithOnlyReturn, If_ $if, Return_ $return): void
+    {
+        $return = clone $return;
+
+        $invertedCondition = $this->createInvertedCondition($nestedIfWithOnlyReturn->cond);
+
+        // special case
+        if ($invertedCondition instanceof BooleanNot) {
+            if ($invertedCondition->expr instanceof BinaryOp\BooleanAnd) {
+                $booleanNotPartIf = new If_(new BooleanNot($invertedCondition->expr->left));
+                $booleanNotPartIf->stmts = [clone $return];
+                $this->addNodeAfterNode($booleanNotPartIf, $if);
+
+                $booleanNotPartIf = new If_(new BooleanNot($invertedCondition->expr->right));
+                $booleanNotPartIf->stmts = [clone $return];
+                $this->addNodeAfterNode($booleanNotPartIf, $if);
+
+                return;
+            }
+        }
+
+        $nestedIfWithOnlyReturn->cond = $invertedCondition;
+        $nestedIfWithOnlyReturn->stmts = [clone $return];
+
+        $this->addNodeAfterNode($nestedIfWithOnlyReturn, $if);
+    }
 }

packages/SOLID/tests/Rector/If_/ChangeIfElseValueAssignToEarlyReturnRector/ChangeIfElseValueAssignToEarlyReturnRectorTest.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\SOLID\Tests\Rector\If_\ChangeIfElseValueAssignToEarlyReturnRector;
+
+use Iterator;
+use Rector\SOLID\Rector\If_\ChangeIfElseValueAssignToEarlyReturnRector;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class ChangeIfElseValueAssignToEarlyReturnRectorTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideDataForTest()
+     */
+    public function test(string $file): void
+    {
+        $this->doTestFile($file);
+    }
+
+    public function provideDataForTest(): Iterator
+    {
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    protected function getRectorClass(): string
+    {
+        return ChangeIfElseValueAssignToEarlyReturnRector::class;
+    }
+}

packages/SOLID/tests/Rector/If_/ChangeIfElseValueAssignToEarlyReturnRector/Fixture/fixture.php.inc

@@ -0,0 +1,37 @@
+<?php
+
+namespace Rector\SOLID\Tests\Rector\If_\ChangeIfElseValueAssignToEarlyReturnRector\Fixture;
+
+class SomeClass
+{
+    public function run()
+    {
+        if ($this->hasDocBlock($tokens, $index)) {
+            $docToken = $tokens[$this->getDocBlockIndex($tokens, $index)];
+        } else {
+            $docToken = null;
+        }
+
+        return $docToken;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\SOLID\Tests\Rector\If_\ChangeIfElseValueAssignToEarlyReturnRector\Fixture;
+
+class SomeClass
+{
+    public function run()
+    {
+        if ($this->hasDocBlock($tokens, $index)) {
+            return $tokens[$this->getDocBlockIndex($tokens, $index)];
+        }
+
+        return null;
+    }
+}
+
+?>

packages/SOLID/tests/Rector/If_/ChangeNestedIfsToEarlyReturnRector/Fixture/boolean_and.php.inc

@@ -0,0 +1,49 @@
+<?php
+
+namespace Rector\SOLID\Tests\Rector\If_\ChangeNestedIfsToEarlyReturnRector\Fixture;
+
+use Rector\NodeTypeResolver\Node\AttributeKey;
+
+class BooleanAnd
+{
+    private function isPreviousExpressionVisuallySimilar(Expression $previousExpression, Node $previousNode): bool
+    {
+        $prePreviousExpression = $previousExpression->getAttribute(AttributeKey::PREVIOUS_STATEMENT);
+        if ($prePreviousExpression instanceof Expression && $prePreviousExpression->expr instanceof AssignOp) {
+            if ($this->areNodesEqual($prePreviousExpression->expr->var, $previousNode->var)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\SOLID\Tests\Rector\If_\ChangeNestedIfsToEarlyReturnRector\Fixture;
+
+use Rector\NodeTypeResolver\Node\AttributeKey;
+
+class BooleanAnd
+{
+    private function isPreviousExpressionVisuallySimilar(Expression $previousExpression, Node $previousNode): bool
+    {
+        $prePreviousExpression = $previousExpression->getAttribute(AttributeKey::PREVIOUS_STATEMENT);
+        if (!$prePreviousExpression instanceof Expression) {
+            return false;
+        }
+        if (!$prePreviousExpression->expr instanceof AssignOp) {
+            return false;
+        }
+        if ($this->areNodesEqual($prePreviousExpression->expr->var, $previousNode->var)) {
+            return true;
+        }
+
+        return false;
+    }
+}
+
+?>

packages/SOLID/tests/Rector/If_/ChangeNestedIfsToEarlyReturnRector/Fixture/having_elseifs.php.inc

@@ -0,0 +1,44 @@
+<?php
+
+namespace Rector\SOLID\Tests\Rector\If_\ChangeNestedIfsToEarlyReturnRector\Fixture;
+
+class HavingElseIfs
+{
+    public function run()
+    {
+        if ($value === 5) {
+            if ($value2 === 10) {
+                return 'yes';
+            } elseif ($value === 555) {
+                return 'maybe';
+            }
+        }
+
+        return 'no';
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\SOLID\Tests\Rector\If_\ChangeNestedIfsToEarlyReturnRector\Fixture;
+
+class HavingElseIfs
+{
+    public function run()
+    {
+        if ($value !== 5) {
+            return 'no';
+        }
+        if ($value2 === 10) {
+            return 'yes';
+        } elseif ($value === 555) {
+            return 'maybe';
+        }
+
+        return 'no';
+    }
+}
+
+?>

packages/SOLID/tests/Rector/If_/ChangeNestedIfsToEarlyReturnRector/Fixture/rector_sample.php.inc

@@ -0,0 +1,86 @@
+<?php
+
+namespace Rector\SOLID\Tests\Rector\If_\ChangeNestedIfsToEarlyReturnRector\Fixture;
+
+use PhpParser\Node\Stmt\If_;
+
+class RectorSample
+{
+    public function run(If_ $node)
+    {
+        // $a < $b
+        if ($node->cond instanceof Smaller) {
+            // $a < $b ? -1
+            if ($this->getValue($node->if) === -1) {
+                // $a < $b ? -1 : ( ?  : )
+                if ($node->else instanceof Ternary) {
+                    // $a < $b ? -1 : ( > ?  : )
+                    if ($node->else->cond instanceof BinaryOp\Greater) {
+                        // $a < $b ? -1 : ($a > $b ?  : )
+                        if ($this->areNodesEqual($node->cond->left, $node->else->cond->left)) {
+                            if ($this->areNodesEqual($node->cond->right, $node->else->cond->right)) {
+                                // $a < $b ? -1 : ($a > $b ? 1 : 0)
+                                if ($this->getValue($node->else->if) === 1) {
+                                    if ($this->getValue($node->else->else) === 0) {
+                                        return new Spaceship($node->cond->left, $node->cond->right);
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        return null;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\SOLID\Tests\Rector\If_\ChangeNestedIfsToEarlyReturnRector\Fixture;
+
+use PhpParser\Node\Stmt\If_;
+
+class RectorSample
+{
+    public function run(If_ $node)
+    {
+        // $a < $b
+        if (!$node->cond instanceof Smaller) {
+            return null;
+        }
+        // $a < $b ? -1
+        if ($this->getValue($node->if) !== -1) {
+            return null;
+        }
+        // $a < $b ? -1 : ( ?  : )
+        if (!$node->else instanceof Ternary) {
+            return null;
+        }
+        // $a < $b ? -1 : ( > ?  : )
+        if (!$node->else->cond instanceof BinaryOp\Greater) {
+            return null;
+        }
+        // $a < $b ? -1 : ($a > $b ?  : )
+        if (!$this->areNodesEqual($node->cond->left, $node->else->cond->left)) {
+            return null;
+        }
+        if (!$this->areNodesEqual($node->cond->right, $node->else->cond->right)) {
+            return null;
+        }
+        // $a < $b ? -1 : ($a > $b ? 1 : 0)
+        if ($this->getValue($node->else->if) !== 1) {
+            return null;
+        }
+        if ($this->getValue($node->else->else) === 0) {
+            return new Spaceship($node->cond->left, $node->cond->right);
+        }
+
+        return null;
+    }
+}
+
+?>

packages/SOLID/tests/Rector/If_/ChangeNestedIfsToEarlyReturnRector/Fixture/skip_single_if.php.inc

@@ -0,0 +1,17 @@
+<?php
+
+namespace Rector\SOLID\Tests\Rector\If_\ChangeNestedIfsToEarlyReturnRector\Fixture;
+
+class SkipSingleIf
+{
+    public function isParameterUsedMethod(Param $param, ClassMethod $classMethod): bool
+    {
+        $compactFuncCalls = $this->betterNodeFinder->find((array) $classMethod->stmts, function (Node $node): bool {
+            if (! $node instanceof FuncCall) {
+                return false;
+            }
+
+            return $this->nameResolver->isName($node, 'compact');
+        });
+    }
+}

rector.yaml

@@ -1,5 +1,6 @@
 services:
-    Rector\DeadCode\Rector\Class_\RemoveUnusedClassesRector: null
+    Rector\SOLID\Rector\If_\ChangeNestedIfsToEarlyReturnRector: null
+#    Rector\SOLID\Rector\If_\ChangeIfElseValueAssignToEarlyReturnRector: null
 
 imports:
     - { resource: "create-rector.yaml", ignore_errors: true }

src/PhpParser/Node/Manipulator/BinaryOpManipulator.php

@@ -77,7 +77,7 @@ final class BinaryOpManipulator
         return new $inversedNodeClass($firstInversedNode, $secondInversedNode);
     }
 
-    public function inverseCondition(BinaryOp $binaryOp): ?BinaryOp
+    public function invertCondition(BinaryOp $binaryOp): ?BinaryOp
     {
         // no nesting
         if ($binaryOp->left instanceof BooleanOr) {

src/PhpParser/Node/Manipulator/IfManipulator.php

@@ -6,8 +6,10 @@ namespace Rector\PhpParser\Node\Manipulator;
 
 use PhpParser\Node;
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\Assign;
 use PhpParser\Node\Expr\BinaryOp\Identical;
 use PhpParser\Node\Expr\BinaryOp\NotIdentical;
+use PhpParser\Node\Expr\Variable;
 use PhpParser\Node\Stmt\Continue_;
 use PhpParser\Node\Stmt\Do_;
 use PhpParser\Node\Stmt\Else_;
@@ -46,14 +48,21 @@ final class IfManipulator
      */
     private $callableNodeTraverser;
 
+    /**
+     * @var StmtsManipulator
+     */
+    private $stmtsManipulator;
+
     public function __construct(
         BetterStandardPrinter $betterStandardPrinter,
         ConstFetchManipulator $constFetchManipulator,
-        CallableNodeTraverser $callableNodeTraverser
+        CallableNodeTraverser $callableNodeTraverser,
+        StmtsManipulator $stmtsManipulator
     ) {
         $this->betterStandardPrinter = $betterStandardPrinter;
         $this->constFetchManipulator = $constFetchManipulator;
         $this->callableNodeTraverser = $callableNodeTraverser;
+        $this->stmtsManipulator = $stmtsManipulator;
     }
 
     /**
@@ -170,6 +179,10 @@ final class IfManipulator
             $currentIf = $currentIf->stmts[0];
         }
 
+        if ($ifs === []) {
+            return [];
+        }
+
         if (! $this->hasOnlyStmtOfType($currentIf, Return_::class)) {
             return [];
         }
@@ -180,6 +193,46 @@ final class IfManipulator
         return $ifs;
     }
 
+    public function isIfWithElse(If_ $if): bool
+    {
+        if ($if->else === null) {
+            return false;
+        }
+
+        return ! (bool) $if->elseifs;
+    }
+
+    public function isIfAndElseWithSameVariableAssignAsLastStmts(If_ $if, Expr $desiredExpr): bool
+    {
+        if (! $this->isIfWithElse($if)) {
+            return false;
+        }
+
+        $lastIfStmt = $this->stmtsManipulator->getUnwrappedLastStmt($if->stmts);
+        if (! $lastIfStmt instanceof Assign) {
+            return false;
+        }
+
+        $lastElseStmt = $this->stmtsManipulator->getUnwrappedLastStmt($if->else->stmts);
+        if (! $lastElseStmt instanceof Assign) {
+            return false;
+        }
+
+        if (! $lastIfStmt->var instanceof Variable) {
+            return false;
+        }
+
+        if (! $this->betterStandardPrinter->areNodesEqual($lastIfStmt->var, $lastElseStmt->var)) {
+            return false;
+        }
+
+        if (! $this->betterStandardPrinter->areNodesEqual($desiredExpr, $lastElseStmt->var)) {
+            return false;
+        }
+
+        return true;
+    }
+
     private function matchComparedAndReturnedNode(NotIdentical $notIdentical, Return_ $returnNode): ?Expr
     {
         if ($this->betterStandardPrinter->areNodesEqual($notIdentical->left, $returnNode->expr)) {
@@ -188,10 +241,11 @@ final class IfManipulator
             }
         }
 
-        if ($this->betterStandardPrinter->areNodesEqual($notIdentical->right, $returnNode->expr)) {
-            if ($this->constFetchManipulator->isNull($notIdentical->left)) {
-                return $notIdentical->right;
-            }
+        if (! $this->betterStandardPrinter->areNodesEqual($notIdentical->right, $returnNode->expr)) {
+            return null;
+        }
+        if ($this->constFetchManipulator->isNull($notIdentical->left)) {
+            return $notIdentical->right;
         }
 
         return null;

src/PhpParser/Node/Manipulator/StmtsManipulator.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\PhpParser\Node\Manipulator;
+
+use PhpParser\Node;
+use PhpParser\Node\Stmt\Expression;
+
+final class StmtsManipulator
+{
+    public function getUnwrappedLastStmt(array $stmts): ?Node
+    {
+        $lastStmtKey = array_key_last($stmts);
+        $lastStmt = $stmts[$lastStmtKey];
+
+        if ($lastStmt instanceof Expression) {
+            return $lastStmt->expr;
+        }
+
+        return $lastStmt;
+    }
+}

utils/RectorGenerator/src/Command/CreateRectorCommand.php

@@ -235,7 +235,7 @@ final class CreateRectorCommand extends Command
         }
 
         $setConfigContent = trim($setConfigContent) . sprintf(
-            '%s%s: ~%s',
+            '%s%s: null%s',
             PHP_EOL,
             $this->indentFourSpaces($rectorFqnName),
             PHP_EOL