From ef37adea0e308528a108c6f17350a41dcfe70fd2 Mon Sep 17 00:00:00 2001
From: Ram <rameshsunkara@users.noreply.github.com>
Date: Wed, 17 Apr 2019 10:24:53 -0400
Subject: [PATCH] Added new Option to configure yakbak to record only
 successful requests (#1)

---
 README.md              |  1 +
 index.js               | 16 +++++++++++++---
 test/helpers/server.js |  6 +++---
 test/yakbak.js         | 29 +++++++++++++++++++++++++++++
 4 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 36d00f9..4e114c0 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,7 @@ var handler = yakbak('http://api.flickr.com', {
 
 - `dirname` the path where recorded responses will be written (required).
 - `noRecord` if true, requests will return a 404 error if the tape doesn't exist
+- `recordOnlySuccess` if true, only successful requests (response status code = 2XX) will be recorded
 - `hash(req, body)` provide your own IncomingMessage hash function
 
 ### with node's http module
diff --git a/index.js b/index.js
index 6a1fdea..7a5fdf8 100644
--- a/index.js
+++ b/index.js
@@ -18,6 +18,7 @@ var debug = require('debug')('yakbak:server');
  * @param {Object} opts
  * @param {String} opts.dirname The tapes directory
  * @param {Boolean} opts.noRecord if true, requests will return a 404 error if the tape doesn't exist
+ * @param {Boolean} opts.recordOnlySuccess if true, only successful requests will be recorded
  * @returns {Function}
  */
 
@@ -31,6 +32,7 @@ module.exports = function (host, opts) {
 
     return buffer(req).then(function (body) {
       var file = path.join(opts.dirname, tapename(req, body));
+      var successfulResCodePattern = /^[2][0|2][0-8]$/;
 
       return Promise.try(function () {
         return require.resolve(file);
@@ -40,7 +42,15 @@ module.exports = function (host, opts) {
           throw new RecordingDisabledError('Recording Disabled');
         } else {
           return proxy(req, body, host).then(function (pres) {
-            return record(pres.req, pres, file);
+            if (opts.recordOnlySuccess === true) {
+                if (successfulResCodePattern.test(pres.statusCode)) {
+                   return record(pres.req, pres, file);
+                } else {
+                  throw new RecordingDisabledError('Only Successful responses will be recorded');
+                }
+            } else {
+              return record(pres.req, pres, file);
+            }
           });
         }
 
@@ -51,7 +61,7 @@ module.exports = function (host, opts) {
       return tape(req, res);
     }).catch(RecordingDisabledError, function (err) {
       /* eslint-disable no-console */
-      console.log('An HTTP request has been made that yakbak does not know how to handle');
+      console.log(err.message);
       console.log(curl.request(req));
       /* eslint-enable no-console */
       res.statusCode = err.status;
@@ -87,7 +97,7 @@ function ModuleNotFoundError(err) {
 
 /**
  * Error class that is thrown when an unmatched request
- * is encountered in noRecord mode
+ * is encountered in noRecord mode or when a request failed in recordOnlySuccess mode
  * @constructor
  */
 
diff --git a/test/helpers/server.js b/test/helpers/server.js
index c0a07b7..92886aa 100644
--- a/test/helpers/server.js
+++ b/test/helpers/server.js
@@ -6,13 +6,13 @@ var http = require('http');
 /**
  * Creates a test HTTP server.
  * @param {Function} done
+ * @param {boolean} failRequest - Specifies whether response has to be error or not
  * @returns {http.Server}
  */
 
-module.exports = function createServer(cb) {
-
+module.exports = function createServer(cb, failRequest) {
   var server = http.createServer(function (req, res) {
-    res.statusCode = 201;
+    res.statusCode = failRequest === true ? 404 : 201;
 
     res.setHeader('Content-Type', 'text/html');
     res.setHeader('Date', 'Sat, 26 Oct 1985 08:20:00 GMT');
diff --git a/test/yakbak.js b/test/yakbak.js
index c16bd81..c182ac7 100644
--- a/test/yakbak.js
+++ b/test/yakbak.js
@@ -135,6 +135,35 @@ describe('yakbak', function () {
         });
       });
     });
+
+    describe("when onlySuccessResponse is enabled", function () {
+      beforeEach(function (done) {
+         /* tear down the server created in global scope as we
+         need different server object which can send response with failed status code*/
+        server.teardown(done);
+      });
+
+      beforeEach(function (done) {
+        /* Send the failed response for the requests this server handles */
+        server = createServer(done, true);
+      });
+
+      beforeEach(function () {
+        yakbak = subject(server.host, { dirname: tmpdir.dirname, recordOnlySuccess: true });
+      });
+
+      it('does not write the tape to disk if response statusCode is not 2XX', function (done) {
+        request(yakbak)
+        .get('/record/2')
+        .set('host', 'localhost:3001')
+        .expect(404)
+        .end(function (err) {
+          assert.ifError(err);
+          assert(!fs.existsSync(tmpdir.join('3234ee470c8605a1837e08f218494326.js')));
+          done();
+        });
+      });
+    });
   });
 
   describe('playback', function () {