Fix #299 - add PossiblyInvalidMethodCall

config.xsd

@@ -158,6 +158,8 @@
             <xs:element name="PossiblyFalseReference" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="PossiblyInvalidArgument" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="PossiblyInvalidArrayAccess" type="IssueHandlerType" minOccurs="0" />
+            <xs:element name="PossiblyInvalidMethodCall" type="IssueHandlerType" minOccurs="0" />
+            <xs:element name="PossiblyInvalidPropertyAssignment" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="PossiblyNullArgument" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="PossiblyNullArrayAccess" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="PossiblyNullFunctionCall" type="IssueHandlerType" minOccurs="0" />

src/Psalm/Checker/Statements/Expression/CallChecker.php

@@ -35,6 +35,7 @@ use Psalm\Issue\ParentNotFound;
 use Psalm\Issue\PossiblyFalseArgument;
 use Psalm\Issue\PossiblyFalseReference;
 use Psalm\Issue\PossiblyInvalidArgument;
+use Psalm\Issue\PossiblyInvalidMethodCall;
 use Psalm\Issue\PossiblyNullArgument;
 use Psalm\Issue\PossiblyNullFunctionCall;
 use Psalm\Issue\PossiblyNullReference;
@@ -764,6 +765,9 @@ class CallChecker
         $non_existent_method_ids = [];
         $existent_method_ids = [];
 
+        $invalid_method_call_types = [];
+        $has_valid_method_call_type = false;
+
         $code_location = new CodeLocation($source, $stmt);
 
         if ($class_type && is_string($stmt->name)) {
@@ -782,15 +786,7 @@ class CallChecker
                         case 'Psalm\\Type\\Atomic\\TArray':
                         case 'Psalm\\Type\\Atomic\\TString':
                         case 'Psalm\\Type\\Atomic\\TNumericString':
-                            if (IssueBuffer::accepts(
+                            $invalid_method_call_types[] = (string)$class_type_part;
-                                new InvalidMethodCall(
-                                    'Cannot call method ' . $stmt->name . ' on ' . $class_type . ' variable ' . $var_id,
-                                    $code_location
-                                ),
-                                $statements_checker->getSuppressedIssues()
-                            )) {
-                                return false;
-                            }
                             break;
 
                         case 'Psalm\\Type\\Atomic\\TMixed':
@@ -810,6 +806,8 @@ class CallChecker
                     continue;
                 }
 
+                $has_valid_method_call_type = true;
+
                 $fq_class_name = $class_type_part->value;
 
                 $intersection_types = $class_type_part->getIntersectionTypes();
@@ -1030,6 +1028,32 @@ class CallChecker
                 }
             }
 
+            if ($invalid_method_call_types) {
+                $class_type = $invalid_method_call_types[0];
+
+                if ($has_valid_method_call_type) {
+                    if (IssueBuffer::accepts(
+                        new PossiblyInvalidMethodCall(
+                            'Cannot call method on possible ' . $class_type . ' variable ' . $var_id,
+                            $code_location
+                        ),
+                        $statements_checker->getSuppressedIssues()
+                    )) {
+                        return false;
+                    }
+                } else {
+                    if (IssueBuffer::accepts(
+                        new InvalidMethodCall(
+                            'Cannot call method on ' . $class_type . ' variable ' . $var_id,
+                            $code_location
+                        ),
+                        $statements_checker->getSuppressedIssues()
+                    )) {
+                        return false;
+                    }
+                }
+            }
+
             if ($non_existent_method_ids) {
                 if ($existent_method_ids) {
                     if (IssueBuffer::accepts(

src/Psalm/Issue/PossiblyInvalidMethodCall.php

@@ -0,0 +1,6 @@
+<?php
+namespace Psalm\Issue;
+
+class PossiblyInvalidMethodCall extends CodeError
+{
+}

tests/MethodCallTest.php

@@ -118,6 +118,26 @@ class MethodCallTest extends TestCase
                     'MixedAssignment',
                 ],
             ],
+            'invalidMethodCall' => [
+                '<?php
+                    ("hello")->someMethod();',
+                'error_message' => 'InvalidMethodCall',
+            ],
+            'possiblyInvalidMethodCall' => [
+                '<?php
+                    class A1 {
+                        public function methodOfA(): void {
+                        }
+                    }
+
+                    /** @param A1|string $x */
+                    function example($x, bool $isObject) {
+                        if ($isObject) {
+                            $x->methodOfA();
+                        }
+                    }',
+                'error_message' => 'PossiblyInvalidMethodCall',
+            ],
             'selfNonStaticInvocation' => [
                 '<?php
                     class A {