From 65d86d35ada562a899064c05474d6c536c7c9e8e Mon Sep 17 00:00:00 2001
From: muglug <github@muglug.com>
Date: Mon, 22 May 2017 11:59:58 -0400
Subject: [PATCH] Separate iterator issues

---
 config.xsd                                    |  2 ++
 .../Statements/Block/ForeachChecker.php       | 30 ++++++++++++++++++-
 src/Psalm/Issue/NullIterator.php              |  6 ++++
 src/Psalm/Issue/PossiblyNullIterator.php      |  6 ++++
 4 files changed, 43 insertions(+), 1 deletion(-)
 create mode 100644 src/Psalm/Issue/NullIterator.php
 create mode 100644 src/Psalm/Issue/PossiblyNullIterator.php

diff --git a/config.xsd b/config.xsd
index b6fccc015..c3b111fb4 100644
--- a/config.xsd
+++ b/config.xsd
@@ -139,6 +139,7 @@
             <xs:element name="NullArgument" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="NullArrayAccess" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="NullFunctionCall" type="IssueHandlerType" minOccurs="0" />
+            <xs:element name="NullIterator" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="NullOperand" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="NullPropertyAssignment" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="NullPropertyFetch" type="IssueHandlerType" minOccurs="0" />
@@ -150,6 +151,7 @@
             <xs:element name="PossiblyNullArgument" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="PossiblyNullArrayAccess" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="PossiblyNullFunctionCall" type="IssueHandlerType" minOccurs="0" />
+            <xs:element name="PossiblyNullIterator" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="PossiblyNullOperand" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="PossiblyNullPropertyAssignment" type="IssueHandlerType" minOccurs="0" />
             <xs:element name="PossiblyNullPropertyFetch" type="IssueHandlerType" minOccurs="0" />
diff --git a/src/Psalm/Checker/Statements/Block/ForeachChecker.php b/src/Psalm/Checker/Statements/Block/ForeachChecker.php
index fd18cc7d7..aac0a9e66 100644
--- a/src/Psalm/Checker/Statements/Block/ForeachChecker.php
+++ b/src/Psalm/Checker/Statements/Block/ForeachChecker.php
@@ -13,6 +13,9 @@ use Psalm\CodeLocation;
 use Psalm\Context;
 use Psalm\Issue\InvalidIterator;
 use Psalm\IssueBuffer;
+use Psalm\Issue\NullIterator;
+use Psalm\Issue\NullReference;
+use Psalm\Issue\PossiblyNullIterator;
 use Psalm\Type;
 
 class ForeachChecker
@@ -54,12 +57,38 @@ class ForeachChecker
         }
 
         if ($iterator_type) {
+            if ($iterator_type->isNull()) {
+                if (IssueBuffer::accepts(
+                    new NullIterator(
+                        'Cannot iterate over null',
+                        new CodeLocation($statements_checker->getSource(), $stmt->expr)
+                    ),
+                    $statements_checker->getSuppressedIssues()
+                )) {
+                    return false;
+                }
+            } elseif ($iterator_type->isNullable() && !$iterator_type->ignore_nullable_issues) {
+                if (IssueBuffer::accepts(
+                    new PossiblyNullIterator(
+                        'Cannot iterate over nullable var ' . $iterator_type,
+                        new CodeLocation($statements_checker->getSource(), $stmt->expr)
+                    ),
+                    $statements_checker->getSuppressedIssues()
+                )) {
+                    return false;
+                }
+            }
+
             foreach ($iterator_type->types as $iterator_type) {
                 // if it's an empty array, we cannot iterate over it
                 if ((string) $iterator_type === 'array<empty, empty>') {
                     continue;
                 }
 
+                if ($iterator_type instanceof Type\Atomic\TNull) {
+                    continue;
+                }
+
                 if ($iterator_type instanceof Type\Atomic\TArray) {
                     if (!$value_type) {
                         $value_type = $iterator_type->type_params[1];
@@ -78,7 +107,6 @@ class ForeachChecker
                 }
 
                 if ($iterator_type instanceof Type\Atomic\Scalar ||
-                    $iterator_type instanceof Type\Atomic\TNull ||
                     $iterator_type instanceof Type\Atomic\TVoid
                 ) {
                     if (IssueBuffer::accepts(
diff --git a/src/Psalm/Issue/NullIterator.php b/src/Psalm/Issue/NullIterator.php
new file mode 100644
index 000000000..0eda60471
--- /dev/null
+++ b/src/Psalm/Issue/NullIterator.php
@@ -0,0 +1,6 @@
+<?php
+namespace Psalm\Issue;
+
+class NullIterator extends CodeError
+{
+}
diff --git a/src/Psalm/Issue/PossiblyNullIterator.php b/src/Psalm/Issue/PossiblyNullIterator.php
new file mode 100644
index 000000000..3b18a2112
--- /dev/null
+++ b/src/Psalm/Issue/PossiblyNullIterator.php
@@ -0,0 +1,6 @@
+<?php
+namespace Psalm\Issue;
+
+class PossiblyNullIterator extends CodeError
+{
+}