From 49f7817a2a0f111b8a5317adf27b9f303fef11c8 Mon Sep 17 00:00:00 2001
From: Matthew Brown <github@muglug.com>
Date: Sat, 31 Dec 2016 09:20:10 -0500
Subject: [PATCH] Emit specific issue when calling instance method with self::

---
 config.xsd                                    |  1 +
 src/Psalm/Checker/MethodChecker.php           | 38 ++++++++++++++-----
 .../Statements/Expression/CallChecker.php     |  1 +
 src/Psalm/Issue/NonStaticSelfCall.php         |  6 +++
 tests/MethodCallTest.php                      | 21 ++++++++++
 5 files changed, 57 insertions(+), 10 deletions(-)
 create mode 100644 src/Psalm/Issue/NonStaticSelfCall.php

diff --git a/config.xsd b/config.xsd
index c8e0e661c..6868c4ee3 100644
--- a/config.xsd
+++ b/config.xsd
@@ -113,6 +113,7 @@
             <xs:element name="MixedPropertyFetch" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="MixedStringOffsetAssignment" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="NoInterfaceProperties" type="IssueHandlerType" minOccurs="0" />
+            <xs:element name="NonStaticSelfCall" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="NullArgument" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="NullArrayAccess" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="NullOperand" type="IssueHandlerType" minOccurs="0" />
diff --git a/src/Psalm/Checker/MethodChecker.php b/src/Psalm/Checker/MethodChecker.php
index 757a0bf30..fbd65d472 100644
--- a/src/Psalm/Checker/MethodChecker.php
+++ b/src/Psalm/Checker/MethodChecker.php
@@ -9,6 +9,7 @@ use Psalm\Issue\DeprecatedMethod;
 use Psalm\Issue\InaccessibleMethod;
 use Psalm\Issue\InvalidDocblock;
 use Psalm\Issue\InvalidStaticInvocation;
+use Psalm\Issue\NonStaticSelfCall;
 use Psalm\Issue\UndefinedMethod;
 use Psalm\IssueBuffer;
 use Psalm\StatementsSource;
@@ -213,12 +214,17 @@ class MethodChecker extends FunctionLikeChecker
      * Determines whether a given method is static or not
      *
      * @param  string          $method_id
+     * @param  bool            $self_call
      * @param  CodeLocation    $code_location
      * @param  array<string>   $suppressed_issues
      * @return bool
      */
-    public static function checkMethodStatic($method_id, CodeLocation $code_location, array $suppressed_issues)
-    {
+    public static function checkMethodStatic(
+        $method_id,
+        $self_call,
+        CodeLocation $code_location,
+        array $suppressed_issues
+    ) {
         self::registerClassMethod($method_id);
 
         /** @var string */
@@ -231,14 +237,26 @@ class MethodChecker extends FunctionLikeChecker
         }
 
         if (!$storage->is_static) {
-            if (IssueBuffer::accepts(
-                new InvalidStaticInvocation(
-                    'Method ' . MethodChecker::getCasedMethodId($method_id) . ' is not static',
-                    $code_location
-                ),
-                $suppressed_issues
-            )) {
-                return false;
+            if ($self_call) {
+                if (IssueBuffer::accepts(
+                    new NonStaticSelfCall(
+                        'Method ' . MethodChecker::getCasedMethodId($method_id) . ' is not static, but is called using self::',
+                        $code_location
+                    ),
+                    $suppressed_issues
+                )) {
+                    return false;
+                }
+            } else {
+                if (IssueBuffer::accepts(
+                    new InvalidStaticInvocation(
+                        'Method ' . MethodChecker::getCasedMethodId($method_id) . ' is not static, but is called statically',
+                        $code_location
+                    ),
+                    $suppressed_issues
+                )) {
+                    return false;
+                }
             }
         }
 
diff --git a/src/Psalm/Checker/Statements/Expression/CallChecker.php b/src/Psalm/Checker/Statements/Expression/CallChecker.php
index a252d39a5..0dab8bb6f 100644
--- a/src/Psalm/Checker/Statements/Expression/CallChecker.php
+++ b/src/Psalm/Checker/Statements/Expression/CallChecker.php
@@ -696,6 +696,7 @@ class CallChecker
                 ) {
                     if (MethodChecker::checkMethodStatic(
                         $method_id,
+                        $stmt->class instanceof PhpParser\Node\Name && $stmt->class->parts[0] === 'self',
                         new CodeLocation($statements_checker->getSource(), $stmt),
                         $statements_checker->getSuppressedIssues()
                     ) === false) {
diff --git a/src/Psalm/Issue/NonStaticSelfCall.php b/src/Psalm/Issue/NonStaticSelfCall.php
new file mode 100644
index 000000000..faf4bd8d4
--- /dev/null
+++ b/src/Psalm/Issue/NonStaticSelfCall.php
@@ -0,0 +1,6 @@
+<?php
+namespace Psalm\Issue;
+
+class NonStaticSelfCall extends CodeError
+{
+}
diff --git a/tests/MethodCallTest.php b/tests/MethodCallTest.php
index 50c042efc..850ffb9e0 100644
--- a/tests/MethodCallTest.php
+++ b/tests/MethodCallTest.php
@@ -101,6 +101,27 @@ class MethodCallTest extends PHPUnit_Framework_TestCase
         $file_checker->check(true, true, $context);
     }
 
+    /**
+     * @expectedException \Psalm\Exception\CodeException
+     * @expectedExceptionMessage NonStaticSelfCall
+     */
+    public function testSelfNonStaticInvocation()
+    {
+        $stmts = self::$parser->parse('<?php
+        class A {
+            public function fooFoo() : void {}
+
+            public function barBar() : void {
+                self::fooFoo();
+            }
+        }
+        ');
+
+        $file_checker = new FileChecker('somefile.php', $stmts);
+        $context = new Context('somefile.php');
+        $file_checker->check(true, true, $context);
+    }
+
     /**
      * @expectedException \Psalm\Exception\CodeException
      * @expectedExceptionMessage ParentNotFound