From 0cfa8f2792a151a163b8c5c854ce54e01e9171be Mon Sep 17 00:00:00 2001
From: analog-nico <nicolai.kamenzky@testrails.org>
Date: Fri, 15 Apr 2016 22:41:26 -0700
Subject: [PATCH] feat: introduced TransformError for failed transforms

---
 lib/errors.js             | 21 ++++++++++++++++++++-
 lib/rp.js                 |  2 +-
 test/spec/request-test.js | 22 ++++++++++++++++++++--
 3 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/lib/errors.js b/lib/errors.js
index 7967754..4cdd196 100644
--- a/lib/errors.js
+++ b/lib/errors.js
@@ -37,7 +37,26 @@ StatusCodeError.prototype = Object.create(Error.prototype);
 StatusCodeError.prototype.constructor = StatusCodeError;
 
 
+function TransformError(cause, options, response) {
+
+    this.name = 'TransformError';
+    this.message = String(cause);
+    this.cause = cause;
+    this.error = cause; // legacy attribute
+    this.options = options;
+    this.response = response;
+
+    if (Error.captureStackTrace) { // if required for non-V8 envs - see PR #40
+        Error.captureStackTrace(this);
+    }
+
+}
+TransformError.prototype = Object.create(Error.prototype);
+TransformError.prototype.constructor = TransformError;
+
+
 module.exports = {
     RequestError: RequestError,
-    StatusCodeError: StatusCodeError
+    StatusCodeError: StatusCodeError,
+    TransformError: TransformError
 };
diff --git a/lib/rp.js b/lib/rp.js
index 3ea968d..cc51d1a 100644
--- a/lib/rp.js
+++ b/lib/rp.js
@@ -68,7 +68,7 @@ function RP$callback(err, response, body) {
             try {
                 self._rp_resolve(self._rp_options.transform(body, response, self._rp_options.resolveWithFullResponse));
             } catch (e) {
-                self._rp_reject(e);
+                self._rp_reject(new errors.TransformError(e, self._rp_options, response));
             }
         } else if (self._rp_options.resolveWithFullResponse) {
             self._rp_resolve(response);
diff --git a/test/spec/request-test.js b/test/spec/request-test.js
index dd8b422..39f9907 100644
--- a/test/spec/request-test.js
+++ b/test/spec/request-test.js
@@ -347,19 +347,37 @@ describe('Request-Promise', function () {
 
         it('that throws an exception', function () {
 
+            var cause = new Error('Transform failed!');
+
             var options = {
                 url: 'http://localhost:4000/200',
                 transform: function (body) {
-                    throw new Error('Transform failed!');
+                    throw cause;
                 }
             };
 
+            var expectedOptions = {
+                url: 'http://localhost:4000/200',
+                simple: true,
+                resolveWithFullResponse: false,
+                transform: options.transform
+            };
+
             return rp(options)
                 .then(function (transformedResponse) {
                     throw new Error('Request should not have been fulfilled!');
                 })
                 .catch(function (err) {
-                    expect(err.message).to.eql('Transform failed!');
+                    expect(err instanceof errors.TransformError).to.eql(true);
+                    expect(err.name).to.eql('TransformError');
+                    expect(err.message).to.eql('Error: Transform failed!');
+                    expect(err.cause).to.eql(cause);
+                    expect(err.error).to.eql(cause);
+                    delete err.options.callback; // Even out Request version differences.
+                    expect(err.options).to.eql(expectedOptions);
+                    expect(err.response).to.be.an('object');
+                    expect(err.response.body).to.eql('GET /200');
+                    expect(err.response.statusCode).to.eql(200);
                 });
 
         });