From 2065e0129ecd496dccf7220f3acc415fd181bf76 Mon Sep 17 00:00:00 2001
From: Matthew Brown <github@muglug.com>
Date: Wed, 7 Nov 2018 08:45:26 -0500
Subject: [PATCH] Fix #1069 - module arithmetic always returns ints

---
 .../Statements/Expression/BinaryOpChecker.php | 20 ++++++++++++++-----
 tests/BinaryOperationTest.php                 | 19 ++++++++++++++++++
 2 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/src/Psalm/Checker/Statements/Expression/BinaryOpChecker.php b/src/Psalm/Checker/Statements/Expression/BinaryOpChecker.php
index b80a62a5e..096966d8a 100644
--- a/src/Psalm/Checker/Statements/Expression/BinaryOpChecker.php
+++ b/src/Psalm/Checker/Statements/Expression/BinaryOpChecker.php
@@ -1011,7 +1011,9 @@ class BinaryOpChecker
             if (($left_type_part instanceof TNumeric || $right_type_part instanceof TNumeric)
                 && ($left_type_part->isNumericType() && $right_type_part->isNumericType())
             ) {
-                if (!$result_type) {
+                if ($parent instanceof PhpParser\Node\Expr\BinaryOp\Mod) {
+                    $result_type = Type::getInt();
+                } elseif (!$result_type) {
                     $result_type = Type::getNumeric();
                 } else {
                     $result_type = Type::combineUnionTypes(Type::getNumeric(), $result_type);
@@ -1024,7 +1026,9 @@ class BinaryOpChecker
             }
 
             if ($left_type_part instanceof TInt && $right_type_part instanceof TInt) {
-                if (!$result_type) {
+                if ($parent instanceof PhpParser\Node\Expr\BinaryOp\Mod) {
+                    $result_type = Type::getInt();
+                } elseif (!$result_type) {
                     $result_type = Type::getInt(true);
                 } else {
                     $result_type = Type::combineUnionTypes(Type::getInt(true), $result_type);
@@ -1037,7 +1041,9 @@ class BinaryOpChecker
             }
 
             if ($left_type_part instanceof TFloat && $right_type_part instanceof TFloat) {
-                if (!$result_type) {
+                if ($parent instanceof PhpParser\Node\Expr\BinaryOp\Mod) {
+                    $result_type = Type::getInt();
+                } elseif (!$result_type) {
                     $result_type = Type::getFloat();
                 } else {
                     $result_type = Type::combineUnionTypes(Type::getFloat(), $result_type);
@@ -1064,7 +1070,9 @@ class BinaryOpChecker
                     }
                 }
 
-                if (!$result_type) {
+                if ($parent instanceof PhpParser\Node\Expr\BinaryOp\Mod) {
+                    $result_type = Type::getInt();
+                } elseif (!$result_type) {
                     $result_type = Type::getFloat();
                 } else {
                     $result_type = Type::combineUnionTypes(Type::getFloat(), $result_type);
@@ -1089,7 +1097,9 @@ class BinaryOpChecker
                     }
                 }
 
-                if (!$result_type) {
+                if ($parent instanceof PhpParser\Node\Expr\BinaryOp\Mod) {
+                    $result_type = Type::getInt();
+                } elseif (!$result_type) {
                     $result_type = Type::getFloat();
                 } else {
                     $result_type = Type::combineUnionTypes(Type::getFloat(), $result_type);
diff --git a/tests/BinaryOperationTest.php b/tests/BinaryOperationTest.php
index 6886ee250..1b0132a39 100644
--- a/tests/BinaryOperationTest.php
+++ b/tests/BinaryOperationTest.php
@@ -89,10 +89,29 @@ class BinaryOperationTest extends TestCase
             'regularAddition' => [
                 '<?php
                     $a = 5 + 4;',
+                'assertions' => [
+                    '$a' => 'int',
+                ],
             ],
             'differingNumericTypesAdditionInWeakMode' => [
                 '<?php
                     $a = 5 + 4.1;',
+                'assertions' => [
+                    '$a' => 'float',
+                ],
+            ],
+            'modulo' => [
+                '<?php
+                    $a = 25 % 2;
+                    $b = 25.4 % 2;
+                    $c = 25 % 2.5;
+                    $d = 25.5 % 2.5;',
+                'assertions' => [
+                    '$a' => 'int',
+                    '$b' => 'int',
+                    '$c' => 'int',
+                    '$d' => 'int',
+                ],
             ],
             'numericAddition' => [
                 '<?php