Fix recognition of variable functions (#27)

* Tests: add failing test for variable function calls

* If a static var is in a class, don't ignore it

* Handle static variable function calls

Author: sirbrillig

VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php

@@ -524,6 +524,12 @@ protected function checkForStaticMember(File $phpcsFile, $stackPtr, $varName, $c
     if (! in_array($tokens[$classNamePtr]['code'], $staticReferences, true)) {
       return false;
     }
+    // "When calling static methods, the function call is stronger than the
+    // static property operator" so look for a function call.
+    $parenPointer = $phpcsFile->findNext(T_OPEN_PARENTHESIS, $stackPtr, $stackPtr + 2);
+    if ($parenPointer) {
+      return false;
+    }
     return true;
   }
 
@@ -555,7 +561,7 @@ protected function checkForStaticOutsideClass(File $phpcsFile, $stackPtr, $varNa
         return true;
       }
       if ($this->areAnyConditionsAClass($token['conditions'])) {
-        return true;
+        return false;
       }
     }
     $phpcsFile->addError(

VariableAnalysis/Tests/CodeAnalysis/VariableAnalysisTest.php

@@ -385,4 +385,16 @@ public function testTraitAllowsThis() {
     $expectedErrors = [];
     $this->assertEquals($expectedErrors, $lines);
   }
+
+  public function testVariableFunctionCallsCountAsUsage() {
+    $fixtureFile = $this->getFixture('FunctionWithVariableCallFixture.php');
+    $phpcsFile = $this->prepareLocalFileForSniffs($this->getSniffFiles(), $fixtureFile);
+    $phpcsFile->process();
+    $lines = $this->getWarningLineNumbersFromFile($phpcsFile);
+    $expectedWarnings = [18];
+    $this->assertEquals($expectedWarnings, $lines);
+    $lines = $this->getErrorLineNumbersFromFile($phpcsFile);
+    $expectedErrors = [];
+    $this->assertEquals($expectedErrors, $lines);
+  }
 }

VariableAnalysis/Tests/CodeAnalysis/fixtures/FunctionWithVariableCallFixture.php

@@ -0,0 +1,44 @@
+<?php
+
+class MyClass {
+    public function funcUsingSelfCallbackFromAlias($meta, $callback) {
+        $get_meta_callback = $callback;
+        return self::$get_meta_callback( $meta  );
+    }
+
+    public function funcUsingSelfCallbackFromArgument($meta, $callback) {
+        return self::$callback( $meta  );
+    }
+
+    public function funcUsingStaticCallbackFromArgument($meta, $callback) {
+        return static::$callback( $meta  );
+    }
+
+    public function funcUsingStaticCallbackWithUndefinedVariable($meta) {
+        return static::$badName( $meta  );
+    }
+
+    public function funcUsingPropertyReference($meta, $callback) {
+        return $this->$callback( $meta  );
+    }
+
+    public function funcUsingDirectCallback($meta, $callback) {
+        return $callback( $meta  );
+    }
+
+    public function funcUsingPropertyReferenceDirectly($meta) {
+        return $meta;
+    }
+
+    public function funcUsingPropertyReferenceWithSelf($meta) {
+        return self::$$meta;
+    }
+
+    public function funcUsingPropertyReferenceWithThis($meta) {
+        return $this->$meta;
+    }
+
+    public function funcUsingPropertyReferenceWithStatic($meta) {
+        return static::$$meta;
+    }
+}