added MysqliEscapeStringDynamicReturnTypeExtension (#28)

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

Author: staabm

README.md

@@ -5,6 +5,7 @@ This extension provides following features:
 * `PDO->query` knows the array shape of the returned results and therefore can return a generic `PDOStatement`
 * `mysqli->query` knows the array shape of the returned results and therefore can return a generic `mysqli_result`
 * `SyntaxErrorInQueryMethodRule` can inspect sql queries and detect syntax errors - `SyntaxErrorInQueryFunctionRule` can do the same for functions
+* `mysqli_real_escape_string` and `mysqli->real_escape_string` dynamic return type extensions
 
 [see the unit-testsuite](https://github.com/staabm/phpstan-dba/tree/main/tests/data) to get a feeling about the current featureset.
 

config/extensions.neon

@@ -14,3 +14,9 @@ services:
         tags:
         	- phpstan.broker.dynamicMethodReturnTypeExtension
         	- phpstan.broker.dynamicFunctionReturnTypeExtension
+
+    -
+        class: staabm\PHPStanDba\Extensions\MysqliEscapeStringDynamicReturnTypeExtension
+        tags:
+        	- phpstan.broker.dynamicMethodReturnTypeExtension
+        	- phpstan.broker.dynamicFunctionReturnTypeExtension

src/Extensions/MysqliEscapeStringDynamicReturnTypeExtension.php

@@ -0,0 +1,80 @@
+<?php
+
+declare(strict_types=1);
+
+namespace staabm\PHPStanDba\Extensions;
+
+use mysqli;
+use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Expr\MethodCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\FunctionReflection;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\Reflection\ParametersAcceptorSelector;
+use PHPStan\Type\Accessory\AccessoryNonEmptyStringType;
+use PHPStan\Type\Accessory\AccessoryNumericStringType;
+use PHPStan\Type\DynamicFunctionReturnTypeExtension;
+use PHPStan\Type\DynamicMethodReturnTypeExtension;
+use PHPStan\Type\IntersectionType;
+use PHPStan\Type\StringType;
+use PHPStan\Type\Type;
+
+final class MysqliEscapeStringDynamicReturnTypeExtension implements DynamicMethodReturnTypeExtension, DynamicFunctionReturnTypeExtension
+{
+    public function getClass(): string
+    {
+        return mysqli::class;
+    }
+
+    public function isMethodSupported(MethodReflection $methodReflection): bool
+    {
+        return 'real_escape_string' === $methodReflection->getName();
+    }
+
+    public function isFunctionSupported(FunctionReflection $functionReflection): bool
+    {
+        return 'mysqli_real_escape_string' === $functionReflection->getName();
+    }
+
+    public function getTypeFromFunctionCall(FunctionReflection $functionReflection, FuncCall $functionCall, Scope $scope): Type
+    {
+        $args = $functionCall->getArgs();
+        if (\count($args) < 2) {
+            return ParametersAcceptorSelector::selectSingle($functionReflection->getVariants())->getReturnType();
+        }
+
+        $argType = $scope->getType($args[1]->value);
+
+        return $this->inferType($argType);
+    }
+
+    public function getTypeFromMethodCall(MethodReflection $methodReflection, MethodCall $methodCall, Scope $scope): Type
+    {
+        $args = $methodCall->getArgs();
+        if (0 === \count($args)) {
+            return ParametersAcceptorSelector::selectSingle($methodReflection->getVariants())->getReturnType();
+        }
+
+        $argType = $scope->getType($args[0]->value);
+
+        return $this->inferType($argType);
+    }
+
+    private function inferType(Type $argType): Type
+    {
+        $intersection = [new StringType()];
+
+        if ($argType->isNumericString()->yes()) {
+            // a numeric string is by definition non-empty. therefore don't combine the e accessories
+            $intersection[] = new AccessoryNumericStringType();
+        } elseif ($argType->isNonEmptyString()->yes()) {
+            $intersection[] = new AccessoryNonEmptyStringType();
+        }
+
+        if (\count($intersection) > 1) {
+            return new IntersectionType($intersection);
+        }
+
+        return new StringType();
+    }
+}

tests/data/mysqli.php

@@ -48,4 +48,26 @@ public function fnQuery(mysqli $mysqli, string $query)
         $result = mysqli_query($mysqli, $query);
         assertType('bool|mysqli_result', $result);
     }
+
+    /**
+     * @param numeric          $n
+     * @param non-empty-string $nonE
+     * @param numeric-string   $numericString
+     */
+    public function escape(mysqli $mysqli, int $i, float $f, $n, string $s, $nonE, string $numericString)
+    {
+        assertType('numeric-string', mysqli_real_escape_string($mysqli, (string) $i));
+        assertType('numeric-string', mysqli_real_escape_string($mysqli, (string) $f));
+        assertType('numeric-string', mysqli_real_escape_string($mysqli, (string) $n));
+        assertType('numeric-string', mysqli_real_escape_string($mysqli, $numericString));
+        assertType('non-empty-string', mysqli_real_escape_string($mysqli, $nonE));
+        assertType('string', mysqli_real_escape_string($mysqli, $s));
+
+        assertType('numeric-string', $mysqli->real_escape_string((string) $i));
+        assertType('numeric-string', $mysqli->real_escape_string((string) $f));
+        assertType('numeric-string', $mysqli->real_escape_string((string) $n));
+        assertType('numeric-string', $mysqli->real_escape_string($numericString));
+        assertType('non-empty-string', $mysqli->real_escape_string($nonE));
+        assertType('string', $mysqli->real_escape_string($s));
+    }
 }