allow multiple closes of the gate

lib/gatejs.js

@@ -10,14 +10,14 @@
 module.exports = function () {
 
     var count = 0;
-    var completion = null;
+    var callbacks = [];
 
     return { enter: enter, exit: exit, close: close };
 
     // enter the gate.
     // returns true if entrance is allowed.
     function enter() {
-        if (!completion) {
+        if (!callbacks.length) {
             count++;
             return true;
         }
@@ -30,21 +30,21 @@ module.exports = function () {
             throw new Error('exit called while nobody was inside');
         }
         if (!(--count)) {
-            if (completion) {
-                completion();
-            }
+            _completion();
         }
     }
 
     // trigger gate closing.
     function close(callback) {
-        if (completion) {
-            throw new Error('close was called more than once');
-        }
-        callback = callback || function () { };
-        completion = callback;
+        callbacks.push(callback || function() {});
         if (!count) {
-            completion();
+            _completion();
+        }
+    }
+
+    function _completion() {
+        if (callbacks.length) {
+            callbacks.forEach(function(cb){ cb(); });
         }
     }
 }

test/gatetest.js

@@ -3,12 +3,13 @@ var gate = require('../main').gate;
 
 module.exports = testCase({
 
-    enterecloseexit: function (test) {
+    // close once
+    test1: function (test) {
         var gate1 = gate();
         var step = 0;
         test.ok(gate1.enter(), 'should be able enter empty gate');
         gate1.close(function () {
-            test.equal(step, 1, 'get clouse completion should come after everybody left');
+            test.equal(step, 1, 'get close completion should come after everybody left');
             step++;
         });
         test.equal(step, 0, 'gate is not closed when somebody inside');
@@ -17,5 +18,27 @@ module.exports = testCase({
         gate1.exit();
         test.equal(step, 2, 'after everybody left, the gate is closed');
         test.done();
+    },
+
+    // close twice
+    test2: function (test) {
+        var gate1 = gate();
+        var step = 0;
+        test.ok(gate1.enter(), 'should be able enter empty gate');
+        gate1.close(function () {
+            test.equal(step, 1, 'get close completion should come after everybody left');
+            step++;
+        });
+        // close again
+        gate1.close(function () {
+            test.equal(step, 2, 'get cluse completion should come after everybody left');
+            step++;
+        });
+        test.equal(step, 0, 'gate is not closed when somebody inside');
+        test.ok(!gate1.enter(), 'should not be able to enter into closing gate');
+        step++;
+        gate1.exit();
+        test.equal(step, 3, 'after everybody left, the gate is closed');
+        test.done();
     }
 });