From 2778c864ff6883f3fc35ebf83031e3c52b874739 Mon Sep 17 00:00:00 2001
From: Guilherme Hermeto <ghermeto@netflix.com>
Date: Wed, 15 May 2019 02:02:46 -0700
Subject: [PATCH] feat: adds support to http problems - RFC7807

adds supports to handle error objects comforming with the http
problem details spec (RFC7807). the spec defines a `status` field
instead of `statusCode` and a `application/problem+json` content
type.
---
 .gitignore              |  1 +
 lib/formatters/index.js |  3 ++-
 lib/response.js         |  9 +++++++--
 lib/server.js           |  2 +-
 test/response.test.js   | 35 +++++++++++++++++++++++++++++++++++
 test/server.test.js     |  3 ++-
 6 files changed, 48 insertions(+), 5 deletions(-)

diff --git a/.gitignore b/.gitignore
index 883db1f28..1a8787318 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,4 @@ deps/javascriptlint
 deps/jsstyle
 package-lock.json
 benchmark/results
+.idea
diff --git a/lib/formatters/index.js b/lib/formatters/index.js
index 467cafb5b..9532bd330 100644
--- a/lib/formatters/index.js
+++ b/lib/formatters/index.js
@@ -18,5 +18,6 @@ module.exports = {
     'application/javascript; q=0.1': require('./jsonp'),
     'application/json; q=0.4': require('./json'),
     'text/plain; q=0.3': require('./text'),
-    'application/octet-stream; q=0.2': require('./binary')
+    'application/octet-stream; q=0.2': require('./binary'),
+    'application/problem+json; q=0.5': require('./json')
 };
diff --git a/lib/response.js b/lib/response.js
index ebf427d42..e04318cf9 100644
--- a/lib/response.js
+++ b/lib/response.js
@@ -389,7 +389,7 @@ function patch(Response) {
         // If the body is an error object and we were not given a status code,
         // try to derive it from the error object, otherwise default to 500
         if (!code && body instanceof Error) {
-            code = body.statusCode || 500;
+            code = body.statusCode || body.status || 500;
         }
 
         // Set sane defaults for optional arguments if they were not provided
@@ -441,7 +441,12 @@ function patch(Response) {
             // Set Content-Type to application/json when
             // res.send is called with an Object instead of calling res.json
             if (!type && typeof body === 'object' && !Buffer.isBuffer(body)) {
-                type = 'application/json';
+                // if Error that conforms with rfc7807 use the correct type
+                if (body instanceof Error && body.status && !body.statusCode) {
+                    type = 'application/problem+json';
+                } else {
+                    type = 'application/json';
+                }
             }
 
             // Derive type if not provided by the user
diff --git a/lib/server.js b/lib/server.js
index d3da14442..05553ff34 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -1435,7 +1435,7 @@ Server.prototype._routeErrorResponse = function _routeErrorResponse(
         }
 
         // only automatically send errors that are known (e.g., restify-errors)
-        if (err instanceof Error && _.isNumber(err.statusCode)) {
+        if (err instanceof Error && _.isNumber(err.statusCode || err.status)) {
             res.send(err);
             return;
         }
diff --git a/test/response.test.js b/test/response.test.js
index a3866af21..4fb0776f9 100644
--- a/test/response.test.js
+++ b/test/response.test.js
@@ -680,3 +680,38 @@ test('GH-1607: should send numbers with explicit status code', function(t) {
         });
     });
 });
+
+test('should handle errors with a status property', function(t) {
+    var notFound = new Error('not found');
+    notFound.status = 404;
+    notFound.title = 'Not Found';
+
+    SERVER.get('/17', function handle(req, res, next) {
+        return next(notFound);
+    });
+
+    CLIENT.get(join(LOCALHOST, '/17'), function(err, _, res, body) {
+        t.equal(res.statusCode, 404);
+        t.equal(res.headers['content-type'], 'application/problem+json');
+        t.equal(body.title, notFound.title);
+        t.end();
+    });
+});
+
+test('should prefer error statusCode property over status', function(t) {
+    var notFound = new Error('not found');
+    notFound.statusCode = 404;
+    notFound.status = 500;
+    notFound.title = 'Not Found';
+
+    SERVER.get('/18', function handle(req, res, next) {
+        return next(notFound);
+    });
+
+    CLIENT.get(join(LOCALHOST, '/18'), function(err, _, res, body) {
+        t.equal(res.statusCode, 404);
+        t.equal(res.headers['content-type'], 'application/json');
+        t.equal(body.title, notFound.title);
+        t.end();
+    });
+});
diff --git a/test/server.test.js b/test/server.test.js
index 4e7e3382d..319a22071 100644
--- a/test/server.test.js
+++ b/test/server.test.js
@@ -2333,7 +2333,8 @@ test('should show debug information', function(t) {
         'application/javascript',
         'application/json',
         'text/plain',
-        'application/octet-stream'
+        'application/octet-stream',
+        'application/problem+json'
     ]);
     t.equal(debugInfo.server.address, '127.0.0.1');
     t.equal(typeof debugInfo.server.port, 'number');