Add docs and tests for graphQLParams

Author: chentsulin

README.md

@@ -144,6 +144,26 @@ The `graphqlHTTP` function accepts the following options:
 
 - **`typeResolver`**
 
+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
+after the request has been parsed.
+
+The `graphQLParams` is provided as the object `{ query, variables, operationName, raw }`.
+
+```js
+app.use(
+  mount(
+    '/graphql',
+    graphqlHTTP(async (request, response, ctx, graphQLParams) => ({
+      schema: MyGraphQLSchema,
+      rootValue: await someFunctionToGetRootValue(request),
+      graphiql: true,
+    })),
+  ),
+);
+```
+
 ## HTTP Usage
 
 Once installed at a path, `koa-graphql` will accept requests with
@@ -336,13 +356,15 @@ package.
 import { NoSchemaIntrospectionCustomRule } from 'graphql';
 
 app.use(
-  '/graphql',
-  graphqlHTTP((request) => {
-    return {
-      schema: MyGraphQLSchema,
-      validationRules: [NoSchemaIntrospectionCustomRule],
-    };
-  }),
+  mount(
+    '/graphql',
+    graphqlHTTP((request) => {
+      return {
+        schema: MyGraphQLSchema,
+        validationRules: [NoSchemaIntrospectionCustomRule],
+      };
+    }),
+  ),
 );
 ```
 

src/__tests__/http-test.ts

@@ -545,6 +545,46 @@ describe('GraphQL-HTTP tests', () => {
       expect(response.text).to.equal('{"data":{"test":"Hello World"}}');
     });
 
+    it('Provides an options function with arguments', async () => {
+      const app = server();
+
+      let seenRequest;
+      let seenResponse;
+      let seenContext;
+      let seenParams;
+
+      app.use(
+        mount(
+          urlString(),
+          graphqlHTTP((req, res, ctx, params) => {
+            seenRequest = req;
+            seenResponse = res;
+            seenContext = ctx;
+            seenParams = params;
+            return { schema: TestSchema };
+          }),
+        ),
+      );
+
+      const response = await request(app.listen()).get(
+        urlString({
+          query: '{test}',
+        }),
+      );
+
+      expect(response.text).to.equal('{"data":{"test":"Hello World"}}');
+
+      expect(seenRequest).to.not.equal(null);
+      expect(seenResponse).to.not.equal(null);
+      expect(seenContext).to.not.equal(null);
+      expect(seenParams).to.deep.equal({
+        query: '{test}',
+        operationName: null,
+        variables: null,
+        raw: false,
+      });
+    });
+
     it('Catches errors thrown from options function', async () => {
       const app = server();
 
@@ -965,7 +1005,7 @@ describe('GraphQL-HTTP tests', () => {
       app.use(
         mount(
           urlString(),
-          graphqlHTTP((_req, ctx) => {
+          graphqlHTTP((_req, _res, ctx) => {
             expect(ctx.req.file?.originalname).to.equal('test.txt');
             return {
               schema: TestMutationSchema,
@@ -1168,10 +1208,10 @@ describe('GraphQL-HTTP tests', () => {
     app.use(
       mount(
         urlString(),
-        graphqlHTTP((reqest, response, context) => {
-          seenRequest = reqest;
-          seenResponse = response;
-          seenContext = context;
+        graphqlHTTP((req, res, ctx) => {
+          seenRequest = req;
+          seenResponse = res;
+          seenContext = ctx;
           return { schema: TestSchema };
         }),
       ),