[code-quality] Add AddReturnTypeToDependedRector (#528)

Author: TomasVotruba

config/sets/phpunit-code-quality.php

@@ -4,6 +4,7 @@
 
 use Rector\Config\RectorConfig;
 use Rector\PHPUnit\CodeQuality\Rector\Class_\AddParamTypeFromDependsRector;
+use Rector\PHPUnit\CodeQuality\Rector\Class_\AddReturnTypeToDependedRector;
 use Rector\PHPUnit\CodeQuality\Rector\Class_\ConstructClassMethodToSetUpTestCaseRector;
 use Rector\PHPUnit\CodeQuality\Rector\Class_\NarrowUnusedSetUpDefinedPropertyRector;
 use Rector\PHPUnit\CodeQuality\Rector\Class_\PreferPHPUnitThisCallRector;
@@ -72,6 +73,7 @@
         TypeWillReturnCallableArrowFunctionRector::class,
         StringCastAssertStringContainsStringRector::class,
         AddParamTypeFromDependsRector::class,
+        AddReturnTypeToDependedRector::class,
 
         NarrowUnusedSetUpDefinedPropertyRector::class,
 

rules-tests/CodeQuality/Rector/Class_/AddReturnTypeToDependedRector/AddReturnTypeToDependedRectorTest.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\AddReturnTypeToDependedRector;
+
+use Iterator;
+use PHPUnit\Framework\Attributes\DataProvider;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class AddReturnTypeToDependedRectorTest extends AbstractRectorTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): Iterator
+    {
+        return self::yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}

rules-tests/CodeQuality/Rector/Class_/AddReturnTypeToDependedRector/Fixture/skip_non_test_methods.php.inc

@@ -0,0 +1,18 @@
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\AddReturnTypeToDependedRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+
+final class SkipNonTestMethods extends TestCase
+{
+    public function nonTestMethod()
+    {
+        return new \stdClass();
+    }
+
+    private function testNotMethod()
+    {
+        return new \stdClass();
+    }
+}

rules-tests/CodeQuality/Rector/Class_/AddReturnTypeToDependedRector/Fixture/skip_silent_void.php.inc

@@ -0,0 +1,17 @@
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\AddReturnTypeToDependedRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+
+final class SkipSilentVoid extends TestCase
+{
+    public function test()
+    {
+        if (rand(0, 1)) {
+            return;
+        }
+
+        return new \stdClass();
+    }
+}

rules-tests/CodeQuality/Rector/Class_/AddReturnTypeToDependedRector/Fixture/some_test.php.inc

@@ -0,0 +1,31 @@
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\AddReturnTypeToDependedRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+
+final class SomeFileTest extends TestCase
+{
+    public function test()
+    {
+        return new \stdClass();
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\AddReturnTypeToDependedRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+
+final class SomeFileTest extends TestCase
+{
+    public function test(): \stdClass
+    {
+        return new \stdClass();
+    }
+}
+
+?>

rules-tests/CodeQuality/Rector/Class_/AddReturnTypeToDependedRector/Fixture/variable_assigned.php.inc

@@ -0,0 +1,35 @@
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\AddReturnTypeToDependedRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+
+final class VaribleAssigned extends TestCase
+{
+    public function test()
+    {
+        $someValue = rand(0, 1);
+
+        return $someValue;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\AddReturnTypeToDependedRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+
+final class VaribleAssigned extends TestCase
+{
+    public function test(): int
+    {
+        $someValue = rand(0, 1);
+
+        return $someValue;
+    }
+}
+
+?>

rules-tests/CodeQuality/Rector/Class_/AddReturnTypeToDependedRector/config/configured_rule.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\PHPUnit\CodeQuality\Rector\Class_\AddReturnTypeToDependedRector;
+
+return RectorConfig::configure()
+    ->withRules([AddReturnTypeToDependedRector::class]);

rules/CodeQuality/Rector/Class_/AddReturnTypeToDependedRector.php

@@ -0,0 +1,150 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\PHPUnit\CodeQuality\Rector\Class_;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Stmt\Class_;
+use PhpParser\Node\Stmt\ClassMethod;
+use Rector\PhpParser\Node\BetterNodeFinder;
+use Rector\PHPStanStaticTypeMapper\Enum\TypeKind;
+use Rector\PHPUnit\NodeAnalyzer\TestsNodeAnalyzer;
+use Rector\Rector\AbstractRector;
+use Rector\StaticTypeMapper\StaticTypeMapper;
+use Rector\TypeDeclaration\NodeAnalyzer\ReturnAnalyzer;
+use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
+use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
+
+/**
+ * @see \Rector\PHPUnit\Tests\CodeQuality\Rector\Class_\AddReturnTypeToDependedRector\AddReturnTypeToDependedRectorTest
+ */
+final class AddReturnTypeToDependedRector extends AbstractRector
+{
+    public function __construct(
+        private readonly TestsNodeAnalyzer $testsNodeAnalyzer,
+        private readonly ReturnAnalyzer $returnAnalyzer,
+        private readonly StaticTypeMapper $staticTypeMapper,
+        private readonly BetterNodeFinder $betterNodeFinder
+    ) {
+    }
+
+    public function getRuleDefinition(): RuleDefinition
+    {
+        return new RuleDefinition(
+            'Add return type declaration to a test method that returns type',
+            [
+                new CodeSample(
+                    <<<'CODE_SAMPLE'
+use PHPUnit\Framework\TestCase;
+
+final class SomeTest extends TestCase
+{
+    public function test()
+    {
+        $value = new \stdClass();
+
+        return $value;
+    }
+}
+CODE_SAMPLE
+
+                    ,
+                    <<<'CODE_SAMPLE'
+use PHPUnit\Framework\TestCase;
+
+final class SomeTest extends TestCase
+{
+    public function test(): \stdClass
+    {
+        $value = new \stdClass();
+
+        return $value;
+    }
+}
+CODE_SAMPLE
+                ),
+            ]
+        );
+    }
+
+    /**
+     * @return array<class-string<Node>>
+     */
+    public function getNodeTypes(): array
+    {
+        return [Class_::class];
+    }
+
+    /**
+     * @param Class_ $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if (! $this->testsNodeAnalyzer->isInTestClass($node)) {
+            return null;
+        }
+
+        $hasChanged = false;
+
+        foreach ($node->getMethods() as $classMethod) {
+            if (! $classMethod->isPublic()) {
+                continue;
+            }
+
+            if (! $this->testsNodeAnalyzer->isTestClassMethod($classMethod)) {
+                continue;
+            }
+
+            if (! $this->haveAllReturnsExpr($classMethod)) {
+                continue;
+            }
+
+            // already known return type
+            if ($classMethod->returnType instanceof Node) {
+                continue;
+            }
+
+            $returns = $this->betterNodeFinder->findReturnsScoped($classMethod);
+            if (! $this->returnAnalyzer->hasOnlyReturnWithExpr($classMethod, $returns)) {
+                return null;
+            }
+
+            if (count($returns) !== 1) {
+                continue;
+            }
+
+            $soleReturnExpr = $returns[0]->expr;
+
+            // does return a type?
+            $returnedExprType = $this->getType($soleReturnExpr);
+            $returnType = $this->staticTypeMapper->mapPHPStanTypeToPhpParserNode($returnedExprType, TypeKind::RETURN);
+
+            if (! $returnType instanceof Node) {
+                continue;
+            }
+
+            $classMethod->returnType = $returnType;
+            $hasChanged = true;
+        }
+
+        if ($hasChanged === false) {
+            return null;
+        }
+
+        return $node;
+    }
+
+    private function haveAllReturnsExpr(ClassMethod $classMethod): bool
+    {
+        $returns = $this->betterNodeFinder->findReturnsScoped($classMethod);
+        foreach ($returns as $return) {
+            if (! $return->expr instanceof Expr) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}