add type to dbal

src/database/mongo/main.js

@@ -79,6 +79,28 @@ module.exports = function (db, module) {
 		});
 	};
 
+	module.type = function (key, callback) {
+		db.collection('objects').findOne({ _key: key }, function (err, data) {
+			if (err) {
+				return callback(err);
+			}
+			if (!data) {
+				return callback(null, null);
+			}
+			var keys = Object.keys(data);
+			if (keys.length === 4 && data.hasOwnProperty('_key') && data.hasOwnProperty('score') && data.hasOwnProperty('value')) {
+				return callback(null, 'zset');
+			} else if (keys.length === 3 && data.hasOwnProperty('_key') && data.hasOwnProperty('members')) {
+				return callback(null, 'set');
+			} else if (keys.length === 3 && data.hasOwnProperty('_key') && data.hasOwnProperty('array')) {
+				return callback(null, 'list');
+			} else if (keys.length === 3 && data.hasOwnProperty('_key') && data.hasOwnProperty('value')) {
+				return callback(null, 'string');
+			}
+			callback(null, 'hash');
+		});
+	};
+
 	module.expire = function (key, seconds, callback) {
 		module.expireAt(key, Math.round(Date.now() / 1000) + seconds, callback);
 	};

src/database/redis/main.js

@@ -60,6 +60,12 @@ module.exports = function (redisClient, module) {
 		});
 	};
 
+	module.type = function (key, callback) {
+		redisClient.type(key, function (err, type) {
+			callback(err, type !== 'none' ? type : null);
+		});
+	};
+
 	module.expire = function (key, seconds, callback) {
 		callback = callback || function () {};
 		redisClient.expire(key, seconds, function (err) {

test/database/keys.js

@@ -170,4 +170,69 @@ describe('Key methods', function () {
 			});
 		});
 	});
+
+	describe('type', function () {
+		it('should return null if key does not exist', function (done) {
+			db.type('doesnotexist', function (err, type) {
+				assert.ifError(err);
+				assert.strictEqual(type, null);
+				done();
+			});
+		});
+
+		it('should return hash as type', function (done) {
+			db.setObject('typeHash', { foo: 1 }, function (err) {
+				assert.ifError(err);
+				db.type('typeHash', function (err, type) {
+					assert.ifError(err);
+					assert.equal(type, 'hash');
+					done();
+				});
+			});
+		});
+
+		it('should return zset as type', function (done) {
+			db.sortedSetAdd('typeZset', 123, 'value1', function (err) {
+				assert.ifError(err);
+				db.type('typeZset', function (err, type) {
+					assert.ifError(err);
+					assert.equal(type, 'zset');
+					done();
+				});
+			});
+		});
+
+		it('should return set as type', function (done) {
+			db.setAdd('typeSet', 'value1', function (err) {
+				assert.ifError(err);
+				db.type('typeSet', function (err, type) {
+					assert.ifError(err);
+					assert.equal(type, 'set');
+					done();
+				});
+			});
+		});
+
+		it('should return list as type', function (done) {
+			db.listAppend('typeList', 'value1', function (err) {
+				assert.ifError(err);
+				db.type('typeList', function (err, type) {
+					assert.ifError(err);
+					assert.equal(type, 'list');
+					done();
+				});
+			});
+		});
+
+		it('should return string as type', function (done) {
+			db.set('typeString', 'value1', function (err) {
+				assert.ifError(err);
+				db.type('typeString', function (err, type) {
+					assert.ifError(err);
+					assert.equal(type, 'string');
+					done();
+				});
+			});
+		});
+	});
 });