fix fatal error on query reflection with AssignOp operators (#450)

Author: staabm

.phpstan-dba-mysqli.cache

@@ -7,6 +7,7 @@
 use PhpParser\Node;
 use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\AssignOp;
 use PhpParser\Node\Expr\MethodCall;
 use PhpParser\Node\Expr\Variable;
 use PhpParser\Node\FunctionLike;
@@ -28,15 +29,25 @@ public function __construct()
     /**
      * @param Variable|MethodCall $expr
      */
-    public function findQueryStringExpression(Expr $expr): ?Expr
+    public function findAssignmentExpression(Expr $expr, bool $skipAssignOps = false): ?Expr
     {
         $current = $expr;
         while (null !== $current) {
+            $matchedAssignOp = false;
+
             /** @var Assign|null $assign */
-            $assign = $this->findFirstPreviousOfNode($current, function ($node) {
+            $assign = $this->findFirstPreviousOfNode($current, function ($node) use (&$matchedAssignOp) {
+                if ($node instanceof Node\Stmt\Expression && $node->expr instanceof AssignOp) {
+                    $matchedAssignOp = true;
+                }
+
                 return $node instanceof Assign;
             });
 
+            if ($skipAssignOps && $matchedAssignOp) {
+                return null;
+            }
+
             if (null !== $assign) {
                 if ($expr instanceof Variable && $this->resolveName($assign->var) === $this->resolveName($expr)) {
                     return $assign->expr;

.phpstan-dba-pdo-mysql.cache

@@ -24,7 +24,7 @@ final class PdoStatementReflection
     public function findPrepareQueryStringExpression(MethodCall $methodCall): ?Expr
     {
         $exprFinder = new ExpressionFinder();
-        $queryExpr = $exprFinder->findQueryStringExpression($methodCall);
+        $queryExpr = $exprFinder->findAssignmentExpression($methodCall);
 
         // resolve query parameter from "prepare"
         if ($queryExpr instanceof MethodCall) {

src/Ast/ExpressionFinder.php

@@ -174,7 +174,7 @@ private function resolveQueryExpr(Expr $queryExpr, Scope $scope): ?string
     {
         if ($queryExpr instanceof Expr\Variable) {
             $finder = new ExpressionFinder();
-            $queryStringExpr = $finder->findQueryStringExpression($queryExpr);
+            $queryStringExpr = $finder->findAssignmentExpression($queryExpr);
 
             if (null !== $queryStringExpr) {
                 return $this->resolveQueryStringExpr($queryStringExpr, $scope);
@@ -191,7 +191,8 @@ private function resolveQueryStringExpr(Expr $queryExpr, Scope $scope, bool $res
     {
         if (true === $resolveVariables && $queryExpr instanceof Expr\Variable) {
             $finder = new ExpressionFinder();
-            $assignExpr = $finder->findQueryStringExpression($queryExpr);
+            // atm we cannot reason about variables which are manipulated via assign ops
+            $assignExpr = $finder->findAssignmentExpression($queryExpr, true);
 
             if (null !== $assignExpr) {
                 return $this->resolveQueryStringExpr($assignExpr, $scope);

src/PdoReflection/PdoStatementReflection.php

@@ -231,4 +231,9 @@ public function testMysqliExecuteQuery(): void
             ],
         ]);
     }
+
+    public function testBugRexstan165()
+    {
+        $this->analyse([__DIR__.'/data/bug-rexstan-165.php'], []);
+    }
 }