WIP: allow the user to disable HTTP 500 if the response contains only errors

README.md

@@ -77,6 +77,8 @@ The `graphqlHTTP` function accepts the following options:
 
   * **`pretty`**: If `true`, any JSON response will be pretty-printed.
 
+  * **`httpErrorOnEmptyData`**: If `false`, the HTTP status code of the response will not be set to 500 if the response contains only errors, not data.
+
   * **`extensions`**: An optional function for adding additional metadata to the
     GraphQL response as a key-value object. The result will be added to
     `"extensions"` field in the resulting JSON. This is often a useful place to

src/index.js

@@ -75,6 +75,13 @@ export type OptionsData = {
    */
   pretty?: ?boolean,
 
+  /**
+   * A boolean to configure whether HTTP status code should be set to 500
+   * if the query did not return any data.
+   * True by default.
+   */
+  httpErrorOnEmptyData?: ?boolean,
+
   /**
    * An optional array of validation rules that will be applied on the document
    * in additional to those defined by the GraphQL spec.
@@ -196,6 +203,7 @@ function graphqlHTTP(options: Options): Middleware {
     let context;
     let params;
     let pretty;
+    let httpErrorOnEmptyData;
     let formatErrorFn = formatError;
     let validateFn = validate;
     let executeFn = execute;
@@ -244,6 +252,7 @@ function graphqlHTTP(options: Options): Middleware {
         const typeResolver = optionsData.typeResolver;
         const graphiql = optionsData.graphiql;
         context = optionsData.context || request;
+        httpErrorOnEmptyData = optionsData.httpErrorOnEmptyData !== false;
 
         let validationRules = specifiedRules;
         if (optionsData.validationRules) {
@@ -375,7 +384,12 @@ function graphqlHTTP(options: Options): Middleware {
         // Note: Information about the error itself will still be contained in
         // the resulting JSON payload.
         // http://facebook.github.io/graphql/#sec-Data
-        if (response.statusCode === 200 && result && !result.data) {
+        if (
+          httpErrorOnEmptyData &&
+          response.statusCode === 200 &&
+          result &&
+          !result.data
+        ) {
           response.statusCode = 500;
         }
         // Format any encountered errors.