From 2d33839d84b54afaa48b460acfe112dee8e2a03e Mon Sep 17 00:00:00 2001
From: Louis Chatriot <louis.chatriot@gmail.com>
Date: Sun, 17 Aug 2014 20:04:42 +0200
Subject: [PATCH] Projections fully tested

---
 lib/datastore.js | 19 ++++++++++++++++---
 test/db.test.js  | 31 ++++++++++++++++++++++++++++++-
 2 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/lib/datastore.js b/lib/datastore.js
index 40943fd..cade891 100644
--- a/lib/datastore.js
+++ b/lib/datastore.js
@@ -404,7 +404,6 @@ Datastore.prototype.find = function (query, projection, callback) {
   });
 
   cursor.projection(projection);
-
   if (typeof callback === 'function') {
     cursor.exec(callback);
   } else {
@@ -416,8 +415,22 @@ Datastore.prototype.find = function (query, projection, callback) {
 /**
  * Find one document matching the query
  * @param {Object} query MongoDB-style query
+ * @param {Object} projection MongoDB-style projection
  */
-Datastore.prototype.findOne = function (query, callback) {
+Datastore.prototype.findOne = function (query, projection, callback) {
+  switch (arguments.length) {
+    case 1:
+      projection = {};
+      // callback is undefined, will return a cursor
+      break;
+    case 2:
+      if (typeof projection === 'function') {
+        callback = projection;
+        projection = {};
+      }   // If not assume projection is an object and callback undefined
+      break;
+  }
+
   var cursor = new Cursor(this, query, function(err, docs, callback) {
     if (err) { return callback(err); }
     if (docs.length === 1) {
@@ -427,7 +440,7 @@ Datastore.prototype.findOne = function (query, callback) {
     }
   });
 
-  cursor.limit(1);
+  cursor.projection(projection).limit(1);
   if (typeof callback === 'function') {
     cursor.exec(callback);
   } else {
diff --git a/test/db.test.js b/test/db.test.js
index d656d34..a02bf3d 100644
--- a/test/db.test.js
+++ b/test/db.test.js
@@ -661,7 +661,7 @@ describe('Database', function () {
       });
     });
 
-    it.only('Can use projections in find, normal or cursor way', function (done) {
+    it('Can use projections in find, normal or cursor way', function (done) {
       d.insert({ a: 2, hello: 'world' }, function (err, doc0) {
         d.insert({ a: 24, hello: 'earth' }, function (err, doc1) {
           d.find({ a: 2 }, { a: 0, _id: 0 }, function (err, docs) {
@@ -692,6 +692,35 @@ describe('Database', function () {
       });
     });
 
+    it('Can use projections in findOne, normal or cursor way', function (done) {
+      d.insert({ a: 2, hello: 'world' }, function (err, doc0) {
+        d.insert({ a: 24, hello: 'earth' }, function (err, doc1) {
+          d.findOne({ a: 2 }, { a: 0, _id: 0 }, function (err, doc) {
+            assert.isNull(err);
+            assert.deepEqual(doc, { hello: 'world' });
+
+            d.findOne({ a: 2 }, { a: 0, _id: 0 }).exec(function (err, doc) {
+              assert.isNull(err);
+              assert.deepEqual(doc, { hello: 'world' });
+
+              // Can't use both modes at once if not _id
+              d.findOne({ a: 2 }, { a: 0, hello: 1 }, function (err, doc) {
+                assert.isNotNull(err);
+                assert.isUndefined(doc);
+
+                d.findOne({ a: 2 }, { a: 0, hello: 1 }).exec(function (err, doc) {
+                  assert.isNotNull(err);
+                  assert.isUndefined(doc);
+
+                  done();
+                });
+              });
+            });
+          });
+        });
+      });
+    });
+
   });   // ==== End of 'Find' ==== //
 
   describe('Count', function() {