Infer default-result type when sql queries cannot be inferred (#373)

Co-authored-by: Markus Staab <[email protected]>

Author: staabm

.phpstan-dba-mysqli.cache

@@ -16,6 +16,7 @@
 use PHPStan\Type\MixedType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeCombinator;
+use staabm\PHPStanDba\PdoReflection\PdoStatementObjectType;
 use staabm\PHPStanDba\PdoReflection\PdoStatementReflection;
 use staabm\PHPStanDba\QueryReflection\QueryReflection;
 use staabm\PHPStanDba\QueryReflection\QueryReflector;
@@ -103,7 +104,24 @@ private function inferType(MethodCall $methodCall, Expr $queryExpr, Scope $scope
         $queryStrings = $queryReflection->resolveQueryStrings($queryExpr, $scope);
 
         $pdoStatementReflection = new PdoStatementReflection();
+        $genericStatement = $pdoStatementReflection->createGenericStatement($queryStrings, $reflectionFetchType);
 
-        return $pdoStatementReflection->createGenericStatement($queryStrings, $reflectionFetchType);
+        if (null !== $genericStatement) {
+            return $genericStatement;
+        }
+
+        $queryStrings = $queryReflection->resolveQueryStrings($queryExpr, $scope);
+        foreach ($queryStrings as $queryString) {
+            if ('SELECT' !== QueryReflection::getQueryType($queryString)) {
+                return null;
+            }
+
+            // return unknown type if query contains syntax errors
+            if (null !== $queryReflection->validateQueryString($queryString)) {
+                return null;
+            }
+        }
+
+        return PdoStatementObjectType::createDefaultType($reflectionFetchType);
     }
 }

.phpstan-dba-pdo-mysql.cache

@@ -6,14 +6,20 @@
 
 use PDOStatement;
 use PHPStan\Type\ArrayType;
+use PHPStan\Type\BenevolentUnionType;
 use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Constant\ConstantArrayTypeBuilder;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\FloatType;
 use PHPStan\Type\Generic\GenericObjectType;
+use PHPStan\Type\IntegerRangeType;
 use PHPStan\Type\IntegerType;
+use PHPStan\Type\MixedType;
 use PHPStan\Type\ObjectType;
+use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
+use PHPStan\Type\UnionType;
 use staabm\PHPStanDba\QueryReflection\QueryReflector;
 
 class PdoStatementObjectType extends GenericObjectType
@@ -94,4 +100,35 @@ private function reduceBothType(Type $bothType, int $fetchType): Type
         // not yet supported fetch type - or $fetchType == BOTH
         return $bothType;
     }
+
+    /**
+     * @param QueryReflector::FETCH_TYPE* $fetchType
+     */
+    public static function createDefaultType(int $fetchType): Type
+    {
+        // we assume native PDO is not able to return bool.
+        $pdoScalar = new UnionType([new IntegerType(), new FloatType(), new StringType()]);
+        $arrayKey = new BenevolentUnionType([new IntegerType(), new StringType()]);
+
+        switch ($fetchType) {
+            case QueryReflector::FETCH_TYPE_CLASS:
+                return new GenericObjectType(PDOStatement::class, [new ObjectType('stdClass')]);
+            case QueryReflector::FETCH_TYPE_KEY_VALUE:
+                $arrayBuilder = ConstantArrayTypeBuilder::createEmpty();
+                $arrayBuilder->setOffsetValueType(new ConstantIntegerType(0), new MixedType());
+                $arrayBuilder->setOffsetValueType(new ConstantIntegerType(1), new MixedType());
+
+                return new GenericObjectType(PDOStatement::class, [$arrayBuilder->getArray()]);
+            case QueryReflector::FETCH_TYPE_NUMERIC:
+                return new GenericObjectType(PDOStatement::class, [new ArrayType(IntegerRangeType::fromInterval(0, null), $pdoScalar)]);
+            case QueryReflector::FETCH_TYPE_ASSOC:
+                return new GenericObjectType(PDOStatement::class, [new ArrayType(new StringType(), $pdoScalar)]);
+            case QueryReflector::FETCH_TYPE_BOTH:
+                return new GenericObjectType(PDOStatement::class, [new ArrayType($arrayKey, $pdoScalar)]);
+            case QueryReflector::FETCH_TYPE_COLUMN:
+                return new GenericObjectType(PDOStatement::class, [$pdoScalar]);
+        }
+
+        return new GenericObjectType(PDOStatement::class, [new MixedType()]);
+    }
 }

src/Extensions/PdoQueryDynamicReturnTypeExtension.php

@@ -62,6 +62,7 @@ public function dataFileAsserts(): iterable
 
         yield from $this->gatherAssertTypes(__DIR__.'/data/pdo-union-result.php');
         yield from $this->gatherAssertTypes(__DIR__.'/data/mysqli-union-result.php');
+        yield from $this->gatherAssertTypes(__DIR__.'/data/pdo-default-fetch-types.php');
         yield from $this->gatherAssertTypes(__DIR__.'/data/bug372.php');
     }