dict: Make copying Dict constructor a class constructor method

(imported from commit 7bd5f6029c1290036a47688cf2b80f9317fe9c13)

static/js/dict.js

@@ -1,27 +1,38 @@
 /* Constructs a new Dict object.
  *
  * Dict() -> the new Dict will be empty
- * Dict(otherdict) -> create a shallow copy of otherdict
- * Dict(jsobj) -> create a Dict with keys corresponding to the properties of
- *                jsobj and values corresponding to the value of the appropriate
- *                property
  */
-function Dict(obj) {
+function Dict() {
     var self = this;
     this._items = {};
+}
+
+/* Constructs a new Dict object from another object.
+ *
+ * Dict.from(otherdict) -> create a shallow copy of otherdict
+ * Dict.from(jsobj) -> create a Dict with keys corresponding to the properties of
+ *                     jsobj and values corresponding to the value of the appropriate
+ *                     property
+ */
+Dict.from = function Dict_from(obj) {
+    var ret = new Dict();
 
     if (typeof obj === "object" && obj !== null) {
         if (obj instanceof Dict) {
             _.each(obj.items(), function (kv) {
-                self.set(kv[0], kv[1]);
+                ret.set(kv[0], kv[1]);
             });
         } else {
             _.each(obj, function (val, key) {
-                self.set(key, val);
+                ret.set(key, val);
             });
         }
+    } else {
+        throw new TypeError("Cannot convert argument to Dict");
     }
-}
+
+    return ret;
+};
 
 (function () {
 

static/js/tutorial.js

@@ -8,9 +8,9 @@ var deferred_work = [];
 // We'll temporarily set stream colors for the streams we use in the demo
 // tutorial messages.
 var real_stream_info;
-var tutorial_stream_info = new Dict({"design": {"color": "#76ce90"},
-                                     "social": {"color": "#fae589"},
-                                     "devel": {"color": "#a6c7e5"}});
+var tutorial_stream_info = Dict.from({"design": {"color": "#76ce90"},
+                                      "social": {"color": "#fae589"},
+                                      "devel": {"color": "#a6c7e5"}});
 
 // Each message object contains the minimal information necessary for it to be
 // processed by our system for adding messages to your feed.

zerver/tests/frontend/node/activity.js

@@ -19,7 +19,7 @@ var activity = global.activity;
     };
 
 
-    global.people_dict = new global.Dict({
+    global.people_dict = new global.Dict.from({
         'alice@zulip.com': 'Alice Smith',
         'fred@zulip.com': 'Fred Flintstone',
         'jill@zulip.com': 'Jill Hill'

zerver/tests/frontend/node/dict.js

@@ -57,10 +57,10 @@ var _ = global._;
 
     assert.deepEqual(d1.items(), []);
 
-    var d2 = new Dict({foo: 'bar', baz: 'qux'});
+    var d2 = Dict.from({foo: 'bar', baz: 'qux'});
     assert.deepEqual(d2.items(), [['foo', 'bar'], ['baz', 'qux']]);
 
-    var d3 = new Dict(d2);
+    var d3 = Dict.from(d2);
     d3.del('foo');
     assert.deepEqual(d2.items(), [['foo', 'bar'], ['baz', 'qux']]);
     assert.deepEqual(d3.items(), [['baz', 'qux']]);

zerver/tests/frontend/node/search_suggestion.js

@@ -108,7 +108,7 @@ var search = set_up_dependencies();
         return 'office';
     };
 
-    global.recent_subjects = new global.Dict({
+    global.recent_subjects = new global.Dict.from({
         office: [
             {subject: 'team'},
             {subject: 'ignore'},
@@ -178,7 +178,7 @@ var search = set_up_dependencies();
         }
     ];
 
-    global.recent_subjects = new global.Dict({
+    global.recent_subjects = new global.Dict.from({
         office: [
             {subject: 'team'},
             {subject: 'ignore'},