Get rid of Body class

The Body class was inlined in the Request and Response classes.
This patch:
- removes the Body class
- adds Request.postData public property
- adds Response.buffer(), Response.text() and Response.json() methods

Fixes #106.

docs/api.md

@@ -97,14 +97,18 @@
   * [class: Request](#class-request)
     + [request.headers](#requestheaders)
     + [request.method](#requestmethod)
+    + [request.postData](#requestpostdata)
     + [request.response()](#requestresponse)
     + [request.url](#requesturl)
   * [class: Response](#class-response)
+    + [response.buffer()](#responsebuffer)
     + [response.headers](#responseheaders)
+    + [response.json()](#responsejson)
     + [response.ok](#responseok)
     + [response.request()](#responserequest)
     + [response.status](#responsestatus)
     + [response.statusText](#responsestatustext)
+    + [response.text()](#responsetext)
     + [response.url](#responseurl)
   * [class: InterceptedRequest](#class-interceptedrequest)
     + [interceptedRequest.abort()](#interceptedrequestabort)
@@ -113,10 +117,6 @@
     + [interceptedRequest.method](#interceptedrequestmethod)
     + [interceptedRequest.postData](#interceptedrequestpostdata)
     + [interceptedRequest.url](#interceptedrequesturl)
-  * [class: Body](#class-body)
-    + [body.buffer()](#bodybuffer)
-    + [body.json()](#bodyjson)
-    + [body.text()](#bodytext)
 
 <!-- tocstop -->
 
@@ -988,6 +988,10 @@ If request gets a 'redirect' response, the request is successfully finished with
 
 Contains the request's method (GET, POST, etc.)
 
+#### request.postData
+- <[string]>
+
+Contains the request's post body, if any.
 
 #### request.response()
 - returns: <[Response]> A matching [Response] object, or `null` if the response has not been received yet.
@@ -1001,9 +1005,17 @@ Contains the URL of the request.
 
 [Response] class represents responses which are received by page. [Response] implements [Body] mixin, which allows clients to call `response.json()` or `response.text()` to get different representations of response body.
 
+#### response.buffer()
+- returns: <Promise<[Buffer]>> Promise which resolves to a buffer with response body.
+
 #### response.headers
 - <[Map]> A map of HTTP headers associated with the response.
 
+#### response.json()
+- returns: <Promise<[Object]>> Promise which resolves to a JSON representation of response body.
+
+This method will throw if the response body is not parsable via `JSON.parse`.
+
 #### response.ok
 - <[boolean]>
 
@@ -1012,18 +1024,18 @@ Contains a boolean stating whether the response was successful (status in the ra
 #### response.request()
 - returns: <[Request]> A matching [Request] object.
 
-
 #### response.status
 - <[number]>
 
 Contains the status code of the response (e.g., 200 for a success).
 
-
 #### response.statusText
 - <[string]>
 
 Contains the status message corresponding to the status code (e.g., OK for 200).
 
+#### response.text()
+- returns: <Promise<[text]>> Promise which resolves to a text representation of response body.
 
 #### response.url
 - <[string]>
@@ -1067,16 +1079,6 @@ Contains `POST` data for `POST` requests.
 
 If changed, the request url will be modified in a way that's not observable by page. Must not be changed in response to an authChallenge.
 
-### class: Body
-
-#### body.buffer()
-- returns: <Promise<[Buffer]>>
-
-#### body.json()
-- returns: <Promise<[Object]>>
-
-#### body.text()
-- returns: <Promise<[text]>>
 
 [Array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array "Array"
 [boolean]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type "Boolean"

lib/NetworkManager.js

@@ -137,14 +137,42 @@ class NetworkManager extends EventEmitter {
   }
 }
 
-class Body {
+class Request {
   /**
+   * @param {!Object} payload
+   */
+  constructor(payload) {
+    this._response = null;
+    this.url = payload.url;
+    this.method = payload.method;
+    this.postData = payload.postData;
+    this.headers = new Map(Object.entries(payload.headers));
+  }
+
+  /**
+   * @return {?Response}
+   */
+  response() {
+    return this._response;
+  }
+}
+helper.tracePublicAPI(Request);
+
+class Response {
+  /**
+   * @param {?Request} request
+   * @param {!Object} payload
    * @param {function():!Promise<!Buffer>} contentCallback
    */
-  constructor(contentCallback) {
+  constructor(request, payload, contentCallback) {
+    this._request = request;
     this._contentCallback = contentCallback;
-    /** @type {?Promise<!Buffer>} */
     this._contentPromise = null;
+    this.headers = new Map(Object.entries(payload.headers));
+    this.ok = payload.status >= 200 && payload.status <= 299;
+    this.status = payload.status;
+    this.statusText = payload.statusText;
+    this.url = payload.url;
   }
 
   /**
@@ -171,45 +199,6 @@ class Body {
     let content = await this.text();
     return JSON.parse(content);
   }
-}
-helper.tracePublicAPI(Body);
-
-class Request extends Body {
-  /**
-   * @param {!Object} payload
-   */
-  constructor(payload) {
-    super(() => Promise.resolve(payload.postData || ''));
-    this._response = null;
-    this.url = payload.url;
-    this.method = payload.method;
-    this.headers = new Map(Object.entries(payload.headers));
-  }
-
-  /**
-   * @return {?Response}
-   */
-  response() {
-    return this._response;
-  }
-}
-helper.tracePublicAPI(Request);
-
-class Response extends Body {
-  /**
-   * @param {?Request} request
-   * @param {!Object} payload
-   * @param {function():!Promise<!Buffer>} contentCallback
-   */
-  constructor(request, payload, contentCallback) {
-    super(contentCallback);
-    this._request = request;
-    this.headers = new Map(Object.entries(payload.headers));
-    this.ok = payload.status >= 200 && payload.status <= 299;
-    this.status = payload.status;
-    this.statusText = payload.statusText;
-    this.url = payload.url;
-  }
 
   /**
    * @return {?Response}

test/test.js

@@ -1133,28 +1133,6 @@ describe('Puppeteer', function() {
       expect(result).toBe('<div>hello</div>');
     }));
   });
-  describe('Request implements Body', function() {
-    it('should work', SX(async function() {
-      await page.navigate(EMPTY_PAGE);
-      server.setRoute('/post', (req, res) => res.end());
-      let request = null;
-      page.on('request', r => request = r);
-      await page.evaluate(() => fetch('./post', { method: 'POST', body: JSON.stringify({foo: 'bar'})}));
-      expect(request).toBeTruthy();
-      expect(await request.text()).toBe('{"foo":"bar"}');
-      expect(await request.json()).toEqual({foo: 'bar'});
-    }));
-  });
-  describe('Response implements Body', function() {
-    it('should work', SX(async function() {
-      let response = null;
-      page.on('response', r => response = r);
-      await page.navigate(PREFIX + '/simple.json');
-      expect(response).toBeTruthy();
-      expect(await response.text()).toBe('{"foo": "bar"}\n');
-      expect(await response.json()).toEqual({foo: 'bar'});
-    }));
-  });
   describe('Network Events', function() {
     it('Page.Events.Request', SX(async function() {
       let requests = [];
@@ -1165,6 +1143,15 @@ describe('Puppeteer', function() {
       expect(requests[0].method).toBe('GET');
       expect(requests[0].response()).toBeTruthy();
     }));
+    it('Page.Events.Request should report post data', SX(async function() {
+      await page.navigate(EMPTY_PAGE);
+      server.setRoute('/post', (req, res) => res.end());
+      let request = null;
+      page.on('request', r => request = r);
+      await page.evaluate(() => fetch('./post', { method: 'POST', body: JSON.stringify({foo: 'bar'})}));
+      expect(request).toBeTruthy();
+      expect(request.postData).toBe('{"foo":"bar"}');
+    }));
     it('Page.Events.Response', SX(async function() {
       let responses = [];
       page.on('response', response => responses.push(response));
@@ -1175,6 +1162,14 @@ describe('Puppeteer', function() {
       expect(responses[0].ok).toBe(true);
       expect(responses[0].request()).toBeTruthy();
     }));
+    it('Page.Events.Response should provide body', SX(async function() {
+      let response = null;
+      page.on('response', r => response = r);
+      await page.navigate(PREFIX + '/simple.json');
+      expect(response).toBeTruthy();
+      expect(await response.text()).toBe('{"foo": "bar"}\n');
+      expect(await response.json()).toEqual({foo: 'bar'});
+    }));
     it('Page.Events.RequestFailed', SX(async function() {
       page.setRequestInterceptor(request => {
         if (request.url.endsWith('css'))