Invent navigate helper to untangle nested callbacks in tests

Author: mislav

test/unit/helpers.js

@@ -0,0 +1,47 @@
+// Navigation helper for the test iframe. Queues navigation actions and
+// callbacks, then executes them serially with respect to async. This is to
+// avoid deep nesting of callbacks in tests.
+//
+// After last successful navigation, asyncTest is automatically resumed.
+//
+// Usage:
+//
+//   navigate(this.frame)
+//   .pjax(pjaxOptions, function(frame){ ... }
+//   .back(-1, function(frame){ ... }
+//
+function navigate(frame) {
+  var queue = []
+  var api = {}
+
+  api.pjax = function(options, callback) {
+    queue.push([options, callback])
+    return api
+  }
+  api.back = api.pjax
+
+  var workOff = function() {
+    var item = queue.shift()
+    if (!item) {
+      start()
+      return
+    }
+
+    var target = item[0], callback = item[1]
+
+    frame.$(frame.document).one("pjax:end", function() {
+      if (callback) callback(frame)
+      setTimeout(workOff, 0)
+    })
+
+    if (typeof target == "number") {
+      frame.history.go(target)
+    } else {
+      frame.$.pjax(target)
+    }
+  }
+
+  setTimeout(workOff, 0)
+
+  return api
+}

test/views/qunit.erb

@@ -9,6 +9,7 @@
   <script type="text/javascript" src="/vendor/qunit.js"></script>
   <script type="text/javascript">QUnit.config.testTimeout = 10000</script>
   <script type="text/javascript" src="/jquery.pjax.js"></script>
+  <script type="text/javascript" src="/test/unit/helpers.js"></script>
   <script type="text/javascript" src="/test/unit/pjax.js"></script>
   <script type="text/javascript" src="/test/unit/fn_pjax.js"></script>
   <script type="text/javascript" src="/test/unit/pjax_fallback.js"></script>