Fix param-only transition between child states

Param changes only in a child-most state should not trigger a parent
transition. Previously, the whole tree was exited and re-entered if a
param owned by the child-most state is changing.

dist/abyssa-with-deps.js

@@ -2915,7 +2915,7 @@ var when = (function(global) {
 /*! @license
  * abyssa <https://github.com/AlexGalays/abyssa-js/>
  * Author: Alexandre Galays | MIT License
- * v1.2.13 (2013-11-28T09:57:47.157Z)
+ * v1.2.14 (2013-12-04T14:13:38.914Z)
  */
 (function () {
 var factory = function () {
@@ -3160,6 +3160,7 @@ function doTransition(enters, exits, params) {
 
 /**
  * Finds the top-most current state's parent that must be exited.
+ * For paramOnlyChange, fromState is also checked for owning params.
  *
  * @param {Abyssa.State} fromState The original state.
  * @param {Abyssa.State} toState The target state.
@@ -3173,7 +3174,8 @@ function transitionRoot(fromState, toState, paramOnlyChange, paramDiff) {
 
   // For a param-only change, the root is the top-most state owning the param(s),
   if (paramOnlyChange) {
-    fromState.parents.slice().reverse().forEach(function(parent) {
+    [fromState].concat(fromState.parents).reverse().forEach(function(parent) {
+      if (root) return;
       for (var param in paramDiff) {
         if (parent.params[param] || parent.queryParams[param]) {
           root = parent;

dist/abyssa.js

@@ -1,7 +1,7 @@
 /*! @license
  * abyssa <https://github.com/AlexGalays/abyssa-js/>
  * Author: Alexandre Galays | MIT License
- * v1.2.13 (2013-11-28T09:57:47.157Z)
+ * v1.2.14 (2013-12-04T14:13:38.914Z)
  */
 (function () {
 var factory = function (signals, crossroads, when, history) {
@@ -246,6 +246,7 @@ function doTransition(enters, exits, params) {
 
 /**
  * Finds the top-most current state's parent that must be exited.
+ * For paramOnlyChange, fromState is also checked for owning params.
  *
  * @param {Abyssa.State} fromState The original state.
  * @param {Abyssa.State} toState The target state.
@@ -259,7 +260,8 @@ function transitionRoot(fromState, toState, paramOnlyChange, paramDiff) {
 
   // For a param-only change, the root is the top-most state owning the param(s),
   if (paramOnlyChange) {
-    fromState.parents.slice().reverse().forEach(function(parent) {
+    [fromState].concat(fromState.parents).reverse().forEach(function(parent) {
+      if (root) return;
       for (var param in paramDiff) {
         if (parent.params[param] || parent.queryParams[param]) {
           root = parent;

package.json

@@ -3,7 +3,7 @@
     "description" : "A stateful router library for single page applications",
     "keywords" : ["routes", "routing", "router", "hierarchical", "stateful"],
     "homepage" : "https://github.com/AlexGalays/abyssa-js/",
-    "version" : "1.2.13",
+    "version" : "1.2.14",
     "author" : {
         "name" : "Alexandre Galays",
         "url" : "https://github.com/AlexGalays/"

src/Transition.js

@@ -111,6 +111,7 @@ function doTransition(enters, exits, params) {
 
 /**
  * Finds the top-most current state's parent that must be exited.
+ * For paramOnlyChange, fromState is also checked for owning params.
  *
  * @param {Abyssa.State} fromState The original state.
  * @param {Abyssa.State} toState The target state.
@@ -124,7 +125,8 @@ function transitionRoot(fromState, toState, paramOnlyChange, paramDiff) {
 
   // For a param-only change, the root is the top-most state owning the param(s),
   if (paramOnlyChange) {
-    fromState.parents.slice().reverse().forEach(function(parent) {
+    [fromState].concat(fromState.parents).reverse().forEach(function(parent) {
+      if (root) return;
       for (var param in paramDiff) {
         if (parent.params[param] || parent.queryParams[param]) {
           root = parent;

test/all-tests.js

@@ -966,6 +966,82 @@ QUnit.asyncTest('Query-only transitions', function() {
 });
 
 
+QUnit.asyncTest('Param changes only in a child-most state should not trigger a parent transition', function() {
+
+  var events = [],
+      lastArticleId;
+
+  var router = Router({
+
+    blog: State('blog', {
+      enter: function() {
+        events.push('blogEnter');
+      },
+
+      exit: function() {
+        events.push('blogExit');
+      },
+
+
+      articles: State('articles/:id', {
+        enter: function(params) {
+          events.push('articlesEnter');
+          lastArticleId = params.id;
+        },
+
+        exit: function() {
+          events.push('articlesExit');
+        }
+
+      })
+
+    })
+
+  }).init('/blog/articles/33');
+
+
+  nextTick()
+    .then(changeParamOnly)
+    .then(stateWasReEntered)
+    .then(addQueryString)
+    .then(stateWasFullyReEntered)
+    .then(changeQueryStringValue)
+    .then(stateWasFullyReEntered)
+    .then(QUnit.start);
+
+
+  function changeParamOnly() {
+    router.state('/blog/articles/44');
+    events = [];
+  }
+
+  // The transition only goes up to the state owning the param
+  function stateWasReEntered() {
+    return nextTick().then(function() {
+      QUnit.assert.deepEqual(events, ['articlesExit', 'articlesEnter']);
+      events = [];
+    });
+  }
+
+  function addQueryString() {
+    router.state('/blog/articles/44?filter=1');
+  }
+
+  // By default, a change in the query will result in a complete transition to the root state and back.
+  function stateWasFullyReEntered() {
+    return nextTick().then(function() {
+      QUnit.assert.deepEqual(events, ['articlesExit', 'blogExit', 'blogEnter', 'articlesEnter']);
+      events = [];
+    });
+  }
+
+  function changeQueryStringValue() {
+    router.state('/blog/articles/44?filter=2');
+  }
+
+});
+
+
 QUnit.asyncTest('The query string is provided to all states', function() {
 
   Router({