Fixed problem

lib/indexes.js

@@ -246,13 +246,23 @@ function append (array, toAppend) {
  * @return {Array of documents}
  */
 Index.prototype.getMatching = function (value) {
-  var res, self = this;
+  var self = this;
 
   if (!util.isArray(value)) {
     return this.tree.search(value);
   } else {
-    res = [];
-    value.forEach(function (v) { append(res, self.getMatching(v)); });
+    var _res = {}, res = [];
+
+    value.forEach(function (v) {
+      self.getMatching(v).forEach(function (doc) {
+        _res[doc._id] = doc;
+      });
+    });
+
+    Object.keys(_res).forEach(function (_id) {
+      res.push(_res[_id]);
+    });
+
     return res;
   }
 };

test/db.test.js

@@ -2479,6 +2479,15 @@ describe('Database', function () {
       
     });   // ==== End of 'Persisting indexes' ====    
 
+    it('Results of getMatching should never contain duplicates', function (done) {
+      d.ensureIndex({ fieldName: 'bad' });
+      d.insert({ bad: ['a', 'b'] }, function () {
+        var res = d.getCandidates({ bad: { $in: ['a', 'b'] } });
+        res.length.should.equal(1);
+        done();
+      });
+    });
+
   });   // ==== End of 'Using indexes' ==== //
 
 

test/indexes.test.js

@@ -628,12 +628,16 @@ describe('Indexes', function () {
     });
 
     it('Can get all documents whose key is in an array of keys', function () {
+      // For this test only we have to use objects with _ids as the array version of getMatching
+      // relies on the _id property being set, otherwise we have to use a quadratic algorithm
+      // or a fingerprinting algorithm, both solutions too complicated and slow given that live nedb
+      // indexes documents with _id always set
       var idx = new Index({ fieldName: 'tf' })
-        , doc1 = { a: 5, tf: 'hello' }
-        , doc2 = { a: 2, tf: 'bloup' }
-        , doc3 = { a: 8, tf: 'world' }
-        , doc4 = { a: 7, tf: 'yes' }
-        , doc5 = { a: 7, tf: 'yes' }
+        , doc1 = { a: 5, tf: 'hello', _id: '1' }
+        , doc2 = { a: 2, tf: 'bloup', _id: '2' }
+        , doc3 = { a: 8, tf: 'world', _id: '3' }
+        , doc4 = { a: 7, tf: 'yes', _id: '4' }
+        , doc5 = { a: 7, tf: 'yes', _id: '5' }
         ;
 
       idx.insert(doc1);