Support array callbacks like [$this, 'method'] (#42)

Author: janedbal

README.md

@@ -49,7 +49,6 @@ class MyEntrypointProvider implements EntrypointProvider
 
 - Only method calls are detected
   - Including static methods, trait methods, interface methods, first class callables, etc.
-  - Callbacks like `[$this, 'method']` are mostly not detected; prefer first class callables `$this->method(...)`
   - Any calls on mixed types are not detected, e.g. `$unknownClass->method()`
   - Expression method calls are not detected, e.g. `$this->$methodName()`
   - Anonymous classes are ignored

src/Collector/MethodCallCollector.php

@@ -5,8 +5,8 @@
 use PhpParser\Node;
 use PhpParser\Node\Attribute;
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\Array_;
 use PhpParser\Node\Expr\CallLike;
-use PhpParser\Node\Expr\FuncCall;
 use PhpParser\Node\Expr\MethodCall;
 use PhpParser\Node\Expr\New_;
 use PhpParser\Node\Expr\NullsafeMethodCall;
@@ -70,8 +70,8 @@ public function processNode(
             $this->registerStaticCall($node, $scope);
         }
 
-        if ($node instanceof FuncCall) {
-            $this->registerFuncCall($node, $scope);
+        if ($node instanceof Array_) {
+            $this->registerArrayCallable($node, $scope);
         }
 
         if ($node instanceof Attribute) {
@@ -153,23 +153,13 @@ private function registerStaticCall(
         }
     }
 
-    private function registerFuncCall(
-        FuncCall $functionCall,
+    private function registerArrayCallable(
+        Array_ $array,
         Scope $scope
     ): void
     {
-        if (!$functionCall->name instanceof Name || $functionCall->name->toString() !== 'array_map') { // we should support all native fns
-            return;
-        }
-
-        if (!isset($functionCall->getArgs()[0])) {
-            return;
-        }
-
-        $callableType = $scope->getType($functionCall->getArgs()[0]->value);
-
-        if ($callableType->isCallable()->yes()) {
-            foreach ($callableType->getConstantArrays() as $constantArray) {
+        if ($scope->getType($array)->isCallable()->yes()) {
+            foreach ($scope->getType($array)->getConstantArrays() as $constantArray) {
                 $callableTypeAndNames = $constantArray->findTypeAndMethodNames();
 
                 foreach ($callableTypeAndNames as $typeAndName) {

tests/Rule/data/DeadMethodRule/array-map-1.php

@@ -8,6 +8,8 @@ class ArrayMapTest
     public function __construct()
     {
         array_map([$this, 'calledMagically'], ['a']);
+        array_filter([], [$this, 'calledMagically2']);
+        [$this, 'calledMagically3'];
     }
 
     private function notCalledMagically(string $foo): string // error: Unused DeadMap\ArrayMapTest::notCalledMagically
@@ -19,6 +21,9 @@ private function calledMagically(string $foo): string
     {
         return $foo;
     }
+
+    private function calledMagically2(): void {}
+    private function calledMagically3(): void {}
 }
 
 new ArrayMapTest();