From 0c984a83bb61584e9379f3b9142dde1dbf8cbb45 Mon Sep 17 00:00:00 2001
From: Daniel Tschinder <daniel.tschinder@researchgate.net>
Date: Sun, 11 Feb 2018 21:18:54 +0100
Subject: [PATCH] Allow constructing GraphQLError with single node.

A common case is encountering an error which blames to a single AST node. Ensure the GraphQLError constructor can handle this case.

ref: graphql/graphql-js#1123
---
 src/Error/Error.php |  6 +++++-
 tests/ErrorTest.php | 18 ++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/Error/Error.php b/src/Error/Error.php
index ccbd323..06a1d12 100644
--- a/src/Error/Error.php
+++ b/src/Error/Error.php
@@ -1,6 +1,7 @@
 <?php
 namespace GraphQL\Error;
 
+use GraphQL\Language\AST\Node;
 use GraphQL\Language\Source;
 use GraphQL\Language\SourceLocation;
 use GraphQL\Utils\Utils;
@@ -139,7 +140,7 @@ class Error extends \Exception implements \JsonSerializable, ClientAware
 
     /**
      * @param string $message
-     * @param array|null $nodes
+     * @param array|Node|null $nodes
      * @param Source $source
      * @param array|null $positions
      * @param array|null $path
@@ -158,8 +159,11 @@ class Error extends \Exception implements \JsonSerializable, ClientAware
     {
         parent::__construct($message, 0, $previous);
 
+        // Compute list of blame nodes.
         if ($nodes instanceof \Traversable) {
             $nodes = iterator_to_array($nodes);
+        } else if ($nodes && !is_array($nodes)) {
+            $nodes = [$nodes];
         }
 
         $this->nodes = $nodes;
diff --git a/tests/ErrorTest.php b/tests/ErrorTest.php
index 8a39970..fc52609 100644
--- a/tests/ErrorTest.php
+++ b/tests/ErrorTest.php
@@ -37,6 +37,24 @@ class ErrorTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals([new SourceLocation(2, 7)], $e->getLocations());
     }
 
+    /**
+     * @it converts single node to positions and locations
+     */
+    public function testConvertSingleNodeToPositionsAndLocations()
+    {
+        $source = new Source('{
+      field
+    }');
+        $ast = Parser::parse($source);
+        $fieldNode = $ast->definitions[0]->selectionSet->selections[0];
+        $e = new Error('msg', $fieldNode); // Non-array value.
+
+        $this->assertEquals([$fieldNode], $e->nodes);
+        $this->assertEquals($source, $e->getSource());
+        $this->assertEquals([8], $e->getPositions());
+        $this->assertEquals([new SourceLocation(2, 7)], $e->getLocations());
+    }
+
     /**
      * @it converts node with loc.start === 0 to positions and locations
      */