update docs and improve tests

README.md

@@ -170,6 +170,19 @@ const server = new Koa()
   .listen();
 ```
 
+By default, `implementSchema` will perform input validation on all of your routes, using the defined `Request` schemas.
+To customize this input validation, specify a `parse` function:
+
+```typescript
+implementSchema(Schema, {
+  // ...
+  parse: (ctx, { endpoint, schema, data }) => {
+    // Validate `data` against the `schema`.
+    // If the data is valid, return it, otherwise throw.
+  },
+});
+```
+
 ### Axios Client Generation
 
 Projects that want to safely consume a service that uses `one-schema` can perform introspection using `fetch-remote-schema`.

src/integration.koa.test.ts

@@ -257,7 +257,7 @@ test('introspection', async () => {
   );
 });
 
-test('default parsing for POST', async () => {
+test('default parsing for POST fails invalid data', async () => {
   await executeTest(
     {
       parse: undefined,
@@ -266,7 +266,7 @@ test('default parsing for POST', async () => {
       },
     },
     async (client) => {
-      const result = await client.post('/posts');
+      const result = await client.post('/posts', {});
 
       expect(result).toMatchObject({
         status: 400,
@@ -276,7 +276,28 @@ test('default parsing for POST', async () => {
   );
 });
 
-test('default parsing for GET', async () => {
+test('default parsing for POST allows valid data', async () => {
+  await executeTest(
+    {
+      parse: undefined,
+      implementation: {
+        'POST /posts': (ctx) => ctx.request.body,
+      },
+    },
+    async (client) => {
+      const result = await client.post('/posts', {
+        id: 'some-id',
+        message: 'some-message',
+      });
+
+      expect(result).toMatchObject({
+        status: 200,
+      });
+    },
+  );
+});
+
+test('default parsing for GET fails invalid data', async () => {
   await executeTest(
     {
       parse: undefined,
@@ -296,3 +317,21 @@ test('default parsing for GET', async () => {
     },
   );
 });
+
+test('default parsing for GET allows valid data', async () => {
+  await executeTest(
+    {
+      parse: undefined,
+      implementation: {
+        'GET /posts': (ctx) => ctx.request.body,
+      },
+    },
+    async (client) => {
+      const result = await client.get('/posts?input=something');
+
+      expect(result).toMatchObject({
+        status: 200,
+      });
+    },
+  );
+});