Merge pull request #1 from jhenriquez/master

Avoids mutating the provided query object.

Author: mihaiberq

src/__tests__/index.js

@@ -132,9 +132,24 @@ describe('mongoose-cursor-pagination', () => {
         }
       )
       .then(results => {
-        should.equal(results.items.length, 5);
-        should.equal(results.hasMore, true);
-        should.equal(results.items[0].value, 994);
-        should.equal(results.items[4].value, 990);
-      }));
+        should.equal(results.items.length, 5)
+        should.equal(results.hasMore, true)
+        should.equal(results.items[0].value, 994)
+        should.equal(results.items[4].value, 990)
+      })
+  })
+
+  it('does not modify the provided query object', function () {
+    const query = {};
+
+    return mongoose.model('User').paginate(query, {
+      key: 'value',
+      sort: { value: -1 },
+      endingBefore: 995,
+    })
+      .then(() => {
+        query.should.eql({})
+      })
+  })
 });
+

src/index.js

@@ -12,7 +12,7 @@ export default function paginationPlugin(schema, pluginOptions) {
   };
 
   schema.statics.paginate = function(query, options, callback) {
-    query = query || {};
+    query = query ?  { ...query } : {};
     options = options || {};
     options.limit = +options.limit || defaultOptions.limit;
     options = { ...defaultOptions, ...options };