NEW: Force low-level errors to throw in dev to prevent errors leaking…

… into JSON response

_config/config.yml

@@ -48,4 +48,4 @@ Only:
 ---
 SilverStripe\TestSession\TestSessionEnvironment:
   extensions:
-    - SilverStripe\GraphQL\Extensions\TestSessionEnvironmentExtension
+    - SilverStripe\GraphQL\Extensions\TestSessionEnvironmentExtension

_config/middlewares.yml

@@ -4,7 +4,6 @@ Name: 'graphql-middlewares'
 SilverStripe\Core\Injector\Injector:
   # default implementation
   SilverStripe\GraphQL\QueryHandler\QueryHandlerInterface:
-    class: SilverStripe\GraphQL\QueryHandler\QueryHandler
     properties:
       Middlewares:
         csrf: '%$SilverStripe\GraphQL\Middleware\CSRFMiddleware'

_config/schema-default.yml

@@ -9,7 +9,8 @@ SilverStripe\Core\Injector\Injector:
       schema: default
       # use a custom handler so it's easy to override/add middlewares in the default schema
       handler: '%$SilverStripe\GraphQL\QueryHandler\QueryHandlerInterface.default'
-
+  SilverStripe\GraphQL\QueryHandler\QueryHandlerInterface.default:
+    class: SilverStripe\GraphQL\QueryHandler\QueryHandler
 SilverStripe\GraphQL\Schema\Schema:
   schemas:
     default:
@@ -35,4 +36,13 @@ SilverStripe\GraphQL\Schema\Schema:
                 before: paginateList
               canView:
                 after: paginateList
-
+---
+Name: graphql-default-dev
+Except:
+  environment: live
+---
+# When not in live mode, throw all errors, so the JSON response doesn't get corrupted with notice/warnings
+SilverStripe\Core\Injector\Injector:
+  SilverStripe\GraphQL\QueryHandler\QueryHandlerInterface.default:
+    properties:
+      errorHandler: [SilverStripe\GraphQL\QueryHandler\DevErrorHandler, handleError]

src/QueryHandler/DevErrorHandler.php

@@ -0,0 +1,30 @@
+<?php
+
+
+namespace SilverStripe\GraphQL\QueryHandler;
+
+/**
+ * Throws everything, including notices, so the JSON response doesn't get corruped by E_NOTICE, E_WARN
+ * outputs.
+ */
+class DevErrorHandler
+{
+    /**
+     * @param $severity
+     * @param $message
+     * @param $filename
+     * @param $line
+     * @return false
+     * @throws QueryException
+     */
+    public static function handleError($severity, $message, $filename, $line)
+    {
+        if (!(error_reporting() & $severity)) {
+            return false;
+        }
+
+        $errstr = htmlspecialchars($errstr);
+
+        throw new QueryException($message);
+    }
+}

src/QueryHandler/QueryException.php

@@ -0,0 +1,10 @@
+<?php
+
+
+namespace SilverStripe\GraphQL\QueryHandler;
+
+use Exception;
+
+class QueryException extends Exception
+{
+}

src/QueryHandler/QueryHandler.php

@@ -53,6 +53,12 @@ class QueryHandler implements
      */
     private $errorFormatter = [self::class, 'formatError'];
 
+    /**
+     * @var callable | null
+     * @config
+     */
+    private $errorHandler = null;
+
     /**
      * @var QueryMiddleware[]
      */
@@ -94,6 +100,9 @@ public function query(GraphQLSchema $schema, $query, ?array $vars = []): array
      */
     public function queryAndReturnResult(GraphQLSchema $schema, $query, ?array $vars = [])
     {
+        if ($this->errorHandler) {
+            set_error_handler($this->errorHandler);
+        }
         $context = $this->getContext();
         $last = function ($schema, $query, $context, $vars) {
             return GraphQL::executeQuery($schema, $query, null, $context, $vars);
@@ -174,6 +183,16 @@ public function setErrorFormatter(callable $errorFormatter): self
         return $this;
     }
 
+    /**
+     * @param callable $errorHandler
+     * @return QueryHandler
+     */
+    public function setErrorHandler(callable $errorHandler): self
+    {
+        $this->errorHandler = $errorHandler;
+        return $this;
+    }
+
     /**
      * @return QueryMiddleware[]
      */