Add support for customValidateFn and rename formatError to customFormatErrorFn

* formatError is deprecated.
* customFormatErrorFn to replace formatError.

Author: jamesmoriarty

README.md

@@ -77,10 +77,6 @@ The `graphqlHTTP` function accepts the following options:
 
   * **`pretty`**: If `true`, any JSON response will be pretty-printed.
 
-  * **`formatError`**: An optional function which will be used to format any
-    errors produced by fulfilling a GraphQL operation. If no function is
-    provided, GraphQL's default spec-compliant [`formatError`][] function will be used.
-
   * **`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
@@ -91,6 +87,16 @@ The `graphqlHTTP` function accepts the following options:
   * **`validationRules`**: Optional additional validation rules queries must
     satisfy in addition to those defined by the GraphQL spec.
 
+  * **`customValidateFn`**: An optional function which will be used to validate
+    instead of default `validate` from `graphql-js`.
+
+  * **`customFormatErrorFn`**:  An optional function which will be used to format any
+    errors produced by fulfilling a GraphQL operation. If no function is
+    provided, GraphQL's default spec-compliant [`formatError`][] function will be used.
+
+  * **`formatError`**: is deprecated and replaced by `customFormatErrorFn`. It will be
+    removed in version 1.0.0.
+
 In addition to an object defining each option, options can also be provided as
 a function (or async function) which returns this options object. This function
 is provided the arguments `(request, response, graphQLParams)` and is called
@@ -288,10 +294,10 @@ graphqlHTTP.getGraphQLParams(request).then(params => {
 ## Debugging Tips
 
 During development, it's useful to get more information from errors, such as
-stack traces. Providing a function to `formatError` enables this:
+stack traces. Providing a function to `customFormatErrorFn` enables this:
 
 ```js
-formatError: error => ({
+customFormatErrorFn: error => ({
   message: error.message,
   locations: error.locations,
   stack: error.stack ? error.stack.split('\n') : [],

src/__tests__/http-test.js

@@ -28,6 +28,7 @@ import {
   GraphQLString,
   GraphQLError,
   BREAK,
+  validate,
 } from 'graphql';
 import graphqlHTTP from '../';
 
@@ -1205,7 +1206,7 @@ describe('test harness', () => {
           urlString(),
           graphqlHTTP({
             schema: TestSchema,
-            formatError(error) {
+            customFormatErrorFn(error) {
               return { message: 'Custom error format: ' + error.message };
             },
           }),
@@ -1236,7 +1237,7 @@ describe('test harness', () => {
           urlString(),
           graphqlHTTP({
             schema: TestSchema,
-            formatError(error) {
+            customFormatErrorFn(error) {
               return {
                 message: error.message,
                 locations: error.locations,
@@ -1466,7 +1467,7 @@ describe('test harness', () => {
         });
       });
 
-      it('allows for custom error formatting of poorly formed requests', async () => {
+      it('`formatError` is deprecated', async () => {
         const app = server();
 
         get(
@@ -1480,6 +1481,46 @@ describe('test harness', () => {
           }),
         );
 
+        const spy = sinon.spy(console, 'warn');
+
+        const response = await request(app).get(
+          urlString({
+            variables: 'who:You',
+            query: 'query helloWho($who: String){ test(who: $who) }',
+          }),
+        );
+
+        expect(
+          spy.calledWith(
+            '`formatError` is deprecated and replaced by `customFormatErrorFn`. It will be removed in version 1.0.0.',
+          ),
+        );
+        expect(response.status).to.equal(400);
+        expect(JSON.parse(response.text)).to.deep.equal({
+          errors: [
+            {
+              message: 'Custom error format: Variables are invalid JSON.',
+            },
+          ],
+        });
+
+        spy.restore();
+      });
+
+      it('allows for custom error formatting of poorly formed requests', async () => {
+        const app = server();
+
+        get(
+          app,
+          urlString(),
+          graphqlHTTP({
+            schema: TestSchema,
+            customFormatErrorFn(error) {
+              return { message: 'Custom error format: ' + error.message };
+            },
+          }),
+        );
+
         const response = await request(app).get(
           urlString({
             variables: 'who:You',
@@ -1859,6 +1900,64 @@ describe('test harness', () => {
       });
     });
 
+    describe('Custom validate function', () => {
+      it('returns data', async () => {
+        const app = server();
+
+        get(
+          app,
+          urlString(),
+          graphqlHTTP({
+            schema: TestSchema,
+            customValidateFn(schema, documentAST, validationRules) {
+              return validate(schema, documentAST, validationRules);
+            },
+          }),
+        );
+
+        const response = await request(app)
+          .get(urlString({ query: '{test}', raw: '' }))
+          .set('Accept', 'text/html');
+
+        expect(response.status).to.equal(200);
+        expect(response.text).to.equal('{"data":{"test":"Hello World"}}');
+      });
+
+      it('returns validation errors', async () => {
+        const app = server();
+
+        get(
+          app,
+          urlString(),
+          graphqlHTTP({
+            schema: TestSchema,
+            customValidateFn(schema, documentAST, validationRules) {
+              const errors = validate(schema, documentAST, validationRules);
+
+              const error = new GraphQLError(`custom error ${errors.length}`);
+
+              return [error];
+            },
+          }),
+        );
+
+        const response = await request(app).get(
+          urlString({
+            query: '{thrower}',
+          }),
+        );
+
+        expect(response.status).to.equal(400);
+        expect(JSON.parse(response.text)).to.deep.equal({
+          errors: [
+            {
+              message: 'custom error 0',
+            },
+          ],
+        });
+      });
+    });
+
     describe('Custom validation rules', () => {
       const AlwaysInvalidRule = function(context) {
         return {
@@ -1946,7 +2045,7 @@ describe('test harness', () => {
           urlString(),
           graphqlHTTP({
             schema: TestSchema,
-            formatError: () => null,
+            customFormatErrorFn: () => null,
             extensions({ result }) {
               return { preservedErrors: (result: any).errors };
             },

src/index.js

@@ -72,18 +72,34 @@ export type OptionsData = {
    */
   pretty?: ?boolean,
 
+  /**
+   * An optional array of validation rules that will be applied on the document
+   * in additional to those defined by the GraphQL spec.
+   */
+  validationRules?: ?Array<(ValidationContext) => ASTVisitor>,
+
+  /**
+   * An optional function which will be used to validate instead of default `validate`
+   * from `graphql-js`.
+   */
+  customValidateFn?: ?(
+    schema: GraphQLSchema,
+    documentAST: DocumentNode,
+    rules: $ReadOnlyArray<any>,
+  ) => $ReadOnlyArray<GraphQLError>,
+
   /**
    * An optional function which will be used to format any errors produced by
    * fulfilling a GraphQL operation. If no function is provided, GraphQL's
    * default spec-compliant `formatError` function will be used.
    */
-  formatError?: ?(error: GraphQLError) => mixed,
+  customFormatErrorFn?: ?(error: GraphQLError) => mixed,
 
   /**
-   * An optional array of validation rules that will be applied on the document
-   * in additional to those defined by the GraphQL spec.
+   * `formatError` is deprecated and replaced by `customFormatErrorFn`. It will
+   *  be removed in version 1.0.0.
    */
-  validationRules?: ?Array<(ValidationContext) => ASTVisitor>,
+  formatError?: ?(error: GraphQLError) => mixed,
 
   /**
    * An optional function for adding additional metadata to the GraphQL response
@@ -158,7 +174,8 @@ function graphqlHTTP(options: Options): Middleware {
     let context;
     let params;
     let pretty;
-    let formatErrorFn;
+    let formatErrorFn = formatError;
+    let validateFn = validate;
     let extensionsFn;
     let showGraphiQL;
     let query;
@@ -201,7 +218,6 @@ function graphqlHTTP(options: Options): Middleware {
         const rootValue = optionsData.rootValue;
         const fieldResolver = optionsData.fieldResolver;
         const graphiql = optionsData.graphiql;
-
         context = optionsData.context || request;
 
         let validationRules = specifiedRules;
@@ -251,7 +267,12 @@ function graphqlHTTP(options: Options): Middleware {
         }
 
         // Validate AST, reporting any errors.
-        const validationErrors = validate(schema, documentAST, validationRules);
+        const validationErrors = validateFn(
+          schema,
+          documentAST,
+          validationRules,
+        );
+
         if (validationErrors.length > 0) {
           // Return 400: Bad Request if any validation errors exist.
           response.statusCode = 400;
@@ -333,9 +354,7 @@ function graphqlHTTP(options: Options): Middleware {
         }
         // Format any encountered errors.
         if (result && result.errors) {
-          (result: any).errors = result.errors.map(
-            formatErrorFn || formatError,
-          );
+          (result: any).errors = result.errors.map(formatErrorFn);
         }
 
         // If allowed to show GraphiQL, present it instead of JSON.
@@ -380,7 +399,18 @@ function graphqlHTTP(options: Options): Middleware {
           );
         }
 
-        formatErrorFn = optionsData.formatError;
+        if (optionsData.formatError) {
+          // eslint-disable-next-line no-console
+          console.warn(
+            '`formatError` is deprecated and replaced by `customFormatErrorFn`. It will be removed in version 1.0.0.',
+          );
+        }
+
+        validateFn = optionsData.customValidateFn || validateFn;
+        formatErrorFn =
+          optionsData.customFormatErrorFn ||
+          optionsData.formatError ||
+          formatErrorFn;
         extensionsFn = optionsData.extensions;
         pretty = optionsData.pretty;
         return optionsData;