Add node JS unit tests for MessageList.

(imported from commit 486a343add91fd5037431504e1ce4a750bfa9fbf)

static/js/message_list.js

@@ -720,3 +720,6 @@ $(document).on('message_selected.zulip hashchange.zulip mousewheel', function (e
 });
 }());
 /*jslint nomen: false */
+if (typeof module !== 'undefined') {
+    module.exports = MessageList;
+}

tools/test-js-with-node

@@ -8,6 +8,7 @@ export NODE_PATH=$STATIC_DIR
 
 NODEJS=$(which nodejs || which node)
 
+$NODEJS message_list.js
 $NODEJS message_tour.js
 $NODEJS unread.js
 $NODEJS search_suggestion.js

zerver/tests/frontend/node/message_list.js

@@ -0,0 +1,99 @@
+// These unit tests for static/js/message_list.js emphasize the model-ish
+// aspects of the MessageList class.  We have to stub out a few functions
+// related to views and events to get the tests working.
+
+var assert = require('assert');
+
+(function set_up_dependencies () {
+    global.document = null;
+    global.$ = function () {
+        return {
+            on: function () {},
+            trigger: function () {}
+        };
+    };
+
+    global._ = require('third/underscore/underscore.js');
+    global.util = require('js/util.js');
+
+}());
+
+var MessageList = require('js/message_list');
+
+(function test_basics() {
+    var table;
+    var filter = {};
+
+    var list = new MessageList(table, filter);
+
+    var messages = [
+        {
+            id: 50,
+            content: 'fifty'
+        },
+        {
+            id: 60
+        },
+        {
+            id: 70
+        },
+        {
+            id: 80
+        }
+    ];
+
+    assert.equal(list.empty(), true);
+
+    list.append(messages, true);
+
+    assert.equal(list.empty(), false);
+    assert.equal(list.first().id, 50);
+    assert.equal(list.last().id, 80);
+
+    assert.equal(list.get(50).content, 'fifty');
+
+    assert.equal(list.closest_id(49), 50);
+    assert.equal(list.closest_id(50), 50);
+    assert.equal(list.closest_id(51), 50);
+    assert.equal(list.closest_id(59), 60);
+    assert.equal(list.closest_id(60), 60);
+    assert.equal(list.closest_id(61), 60);
+
+    assert.deepEqual(list.all(), messages);
+
+    global.$.Event = function (ev) {
+        assert.equal(ev, 'message_selected.zulip');
+    };
+    list.select_id(50);
+
+    assert.equal(list.selected_id(), 50);
+
+    list.advance_past_messages([60, 80]);
+    assert.equal(list.selected_id(), 60);
+
+    var old_messages = [
+        {
+            id: 30
+        },
+        {
+            id: 40
+        }
+    ];
+    list.prepend(old_messages, true);
+    assert.equal(list.first().id, 30);
+    assert.equal(list.last().id, 80);
+
+    var new_messages = [
+        {
+            id: 90
+        }
+    ];
+    list.append(new_messages, true);
+    assert.equal(list.last().id, 90);
+
+
+    list._clear_table = function () {};
+    list.clear();
+    assert.deepEqual(list.all(), []);
+
+}());