adding better mongoose conflict error handling

src/error-handler.js

@@ -14,7 +14,23 @@ export default function errorHandler (error) {
       case 'DivergentArrayError':
         return Promise.reject(new errors.GeneralError(error));
       case 'MongoError':
-        if (error.code === 11000) {
+        if (error.code === 11000 || error.code === 11001) {
+          // NOTE (EK): Error parsing as discussed in this github thread
+          // https://github.com/Automattic/mongoose/issues/2129
+          const key = error.message.match(/_?([a-zA-Z]*)_?\d?\s*dup key/i)[1];
+          let value = error.message.match(/\s*dup key:\s*\{\s*:\s*"?([a-zA-Z0-9'().]+)"?\s*\}/i)[1];
+
+          if (value === 'null') {
+            value = null;
+          } else if (value === 'undefined') {
+            value = undefined;
+          }
+
+          error.message = `${key} '${value}' already exists.`;
+          error.errors = {
+            [key]: value
+          };
+
           return Promise.reject(new errors.Conflict(error));
         }
 

test/error-handler.test.js

@@ -113,13 +113,35 @@ describe('Feathers Mongoose Error Handler', () => {
     }).catch(done);
   });
 
-  it('wraps a DuplicateKey error as a Conflict', done => {
-    let e = Error('Mock Duplicate Key Error');
-    e.name = 'MongoError';
-    e.code = 11000;
-    errorHandler(e).catch(error => {
-      expect(error).to.be.an.instanceof(errors.Conflict);
-      done();
-    }).catch(done);
+  describe('DuplicateKey error', () => {
+    it('gets wrapped as a Conflict error', done => {
+      let e = Error('E11000 duplicate key error collection: db.users index: name_1 dup key: { : "Kate" }');
+      e.name = 'MongoError';
+      e.code = 11000;
+      errorHandler(e).catch(error => {
+        expect(error).to.be.an.instanceof(errors.Conflict);
+        done();
+      }).catch(done);
+    });
+
+    it('has the correct error message', done => {
+      let e = Error("E11000 duplicate key error index: myDb.myCollection.$id dup key: { : ObjectId('57226808ec55240c00000272') }");
+      e.name = 'MongoError';
+      e.code = 11000;
+      errorHandler(e).catch(error => {
+        expect(error.message).to.equal(`id 'ObjectId('57226808ec55240c00000272')' already exists.`);
+        done();
+      }).catch(done);
+    });
+
+    it('has the correct errors object', done => {
+      let e = Error('E11000 duplicate key error index: test.collection.$a.b_1 dup key: { : null }');
+      e.name = 'MongoError';
+      e.code = 11000;
+      errorHandler(e).catch(error => {
+        expect(error.errors).to.deep.equal({ b: null });
+        done();
+      }).catch(done);
+    });
   });
 });