From da19b55db1baa7a2ff41f8f8b129ef3230d0215c Mon Sep 17 00:00:00 2001
From: Matt Brown <github@muglug.com>
Date: Thu, 6 Apr 2017 15:36:22 -0400
Subject: [PATCH] Add special TypeDoesNotContainNull issue as distinct from
 TypeDoesNotContainType

---
 config.xsd                                    |  1 +
 .../Statements/Expression/AssertionFinder.php |  3 +-
 src/Psalm/Checker/TypeChecker.php             | 32 +++++++++++++------
 src/Psalm/Issue/TypeDoesNotContainNull.php    |  6 ++++
 tests/TypeReconciliationTest.php              |  4 +--
 5 files changed, 34 insertions(+), 12 deletions(-)
 create mode 100644 src/Psalm/Issue/TypeDoesNotContainNull.php

diff --git a/config.xsd b/config.xsd
index 2a3136547..3739c9ab0 100644
--- a/config.xsd
+++ b/config.xsd
@@ -157,6 +157,7 @@
             <xs:element name="TooFewArguments" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="TooManyArguments" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="TypeCoercion" type="IssueHandlerType" minOccurs="0" />
+            <xs:element name="TypeDoesNotContainNull" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="TypeDoesNotContainType" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="UndefinedClass" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="UndefinedConstant" type="IssueHandlerType" minOccurs="0" />
diff --git a/src/Psalm/Checker/Statements/Expression/AssertionFinder.php b/src/Psalm/Checker/Statements/Expression/AssertionFinder.php
index fac0a9f8d..bc35fac57 100644
--- a/src/Psalm/Checker/Statements/Expression/AssertionFinder.php
+++ b/src/Psalm/Checker/Statements/Expression/AssertionFinder.php
@@ -7,6 +7,7 @@ use Psalm\Checker\Statements\ExpressionChecker;
 use Psalm\Checker\TypeChecker;
 use Psalm\Clause;
 use Psalm\CodeLocation;
+use Psalm\Issue\TypeDoesNotContainNull;
 use Psalm\Issue\TypeDoesNotContainType;
 use Psalm\IssueBuffer;
 use Psalm\StatementsSource;
@@ -134,7 +135,7 @@ class AssertionFinder
                         $source->getFileChecker()
                     )) {
                         if (IssueBuffer::accepts(
-                            new TypeDoesNotContainType(
+                            new TypeDoesNotContainNull(
                                 $var_type . ' does not contain ' . $null_type,
                                 new CodeLocation($source, $conditional)
                             ),
diff --git a/src/Psalm/Checker/TypeChecker.php b/src/Psalm/Checker/TypeChecker.php
index bb129e958..cd02fb8a1 100644
--- a/src/Psalm/Checker/TypeChecker.php
+++ b/src/Psalm/Checker/TypeChecker.php
@@ -5,6 +5,7 @@ use PhpParser;
 use Psalm\Checker\Statements\ExpressionChecker;
 use Psalm\CodeLocation;
 use Psalm\Issue\FailedTypeResolution;
+use Psalm\Issue\TypeDoesNotContainNull;
 use Psalm\Issue\TypeDoesNotContainType;
 use Psalm\IssueBuffer;
 use Psalm\StatementsSource;
@@ -367,15 +368,28 @@ class TypeChecker
             }
 
             if (!$has_match) {
-                if (IssueBuffer::accepts(
-                    new TypeDoesNotContainType(
-                        'Cannot resolve types for ' . $key . ' - ' . $existing_var_type .
-                        ' does not contain ' . $new_type,
-                        $code_location
-                    ),
-                    $suppressed_issues
-                )) {
-                    // fall through
+                if ($new_var_type === 'null') {
+                    if (IssueBuffer::accepts(
+                        new TypeDoesNotContainNull(
+                            'Cannot resolve types for ' . $key . ' - ' . $existing_var_type .
+                            ' does not contain null',
+                            $code_location
+                        ),
+                        $suppressed_issues
+                    )) {
+                        // fall through
+                    }
+                } else {
+                    if (IssueBuffer::accepts(
+                        new TypeDoesNotContainType(
+                            'Cannot resolve types for ' . $key . ' - ' . $existing_var_type .
+                            ' does not contain ' . $new_type,
+                            $code_location
+                        ),
+                        $suppressed_issues
+                    )) {
+                        // fall through
+                    }
                 }
 
                 $failed_reconciliation = true;
diff --git a/src/Psalm/Issue/TypeDoesNotContainNull.php b/src/Psalm/Issue/TypeDoesNotContainNull.php
new file mode 100644
index 000000000..a4f8b357d
--- /dev/null
+++ b/src/Psalm/Issue/TypeDoesNotContainNull.php
@@ -0,0 +1,6 @@
+<?php
+namespace Psalm\Issue;
+
+class TypeDoesNotContainNull extends CodeError
+{
+}
diff --git a/tests/TypeReconciliationTest.php b/tests/TypeReconciliationTest.php
index 4dd577d14..d51e5ba89 100644
--- a/tests/TypeReconciliationTest.php
+++ b/tests/TypeReconciliationTest.php
@@ -366,7 +366,7 @@ class TypeReconciliationTest extends PHPUnit_Framework_TestCase
 
     /**
      * @expectedException        \Psalm\Exception\CodeException
-     * @expectedExceptionMessage TypeDoesNotContainType
+     * @expectedExceptionMessage TypeDoesNotContainNull
      * @return                   void
      */
     public function testMakeNonNullableNull()
@@ -437,7 +437,7 @@ class TypeReconciliationTest extends PHPUnit_Framework_TestCase
 
     /**
      * @expectedException        \Psalm\Exception\CodeException
-     * @expectedExceptionMessage TypeDoesNotContainType
+     * @expectedExceptionMessage TypeDoesNotContainNull
      * @return                   void
      */
     public function testStringIsNotNull()