return lock id in .lock

README.md

@@ -57,6 +57,22 @@ var maxAttempts = 4; // Max number of times to try setting the lock before error
 var wait = 1000; // Time to wait before another attempt if lock already in place
 warlock.optimistic(key, ttl, maxAttempts, wait, function(err, unlock) {});
 
+// unlock using the lock id
+var key = 'test-lock-2';
+var ttl = 10000;
+var lockId;
+
+warlock.lock(key, ttl, function(err, _, id) {
+  lockId = id;
+});
+
+// each client who knows the lockId can release the lock
+warlock.unlock(key, lockId, function(err, result) {
+  if(result == 1) {
+    // unlocked successfully
+  }
+});
+
 ```
 
 ## ProTips

lib/warlock.js

@@ -36,7 +36,7 @@ module.exports = function(redis){
         var unlock = warlock.unlock.bind(warlock, key, id);
         if (!lockSet) unlock = false;
 
-        return cb(err, unlock);
+        return cb(err, unlock, id);
       }
     );
 

test/warlock.js

@@ -44,3 +44,32 @@ describe('locking', function() {
     });
   });
 });
+
+describe('unlocking with id', function() {
+  var lockId;
+
+  it('sets lock and gets lock id', function(done) {
+    warlock.lock('customlock', 20000, function(err, unlock, id) {
+      should.not.exists(err);
+      id.should.type("string");
+      lockId = id;
+      done();
+    });
+  });
+
+  it('does not unlock with wrong id', function(done) {
+    warlock.unlock('customlock', "wrongid", function(err, result) {
+      should.not.exists(err);
+      result.should.equal(0);
+      done();
+    });
+  });
+
+  it('unlocks', function(done) {
+    warlock.unlock('customlock', lockId, function(err, result) {
+      should.not.exists(err);
+      result.should.equal(1);
+      done();
+    });
+  });
+});