Adding unit tests for i18n.format

lib/i18n.js

@@ -189,6 +189,7 @@ exports.localeFrom = localeFrom = function (language) {
  * format("%s %s", ["Hello", "World"]);
  */
 exports.format = format = function (fmt, obj, named) {
+  if (! fmt) return "";
   if (named) {
     return fmt.replace(/%\(\w+\)s/g, function(match){return String(obj[match.slice(2,-2)])});
   } else {

resources/static/shared/gettext.js

@@ -16,8 +16,8 @@ function Gettext(params) {
       },
       // See lib/i18n.js format docs
       format: function (fmt, obj, named) {
+        if (! fmt) return "";
         if (! fmt.replace) {
-          console.log("format called with", fmt);
           return fmt;
         }
         if (named) {

tests/i18n-tests.js

@@ -0,0 +1,59 @@
+#!/usr/bin/env node
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+require('./lib/test_env.js');
+
+const assert = require('assert'),
+      vows = require('vows'),
+      i18n = require('../lib/i18n');
+
+var suite = vows.describe('i18n');
+
+suite.addBatch({
+  "format a string with place values": {
+    topic: function () {
+      return i18n.format("%s %s!", ["Hello", "World"]);
+    },
+    "was interpolated": function (err, str) {
+      assert.equal(str, "Hello World!");
+    }
+  }
+});
+
+suite.addBatch({
+  "format a string with named values": {
+    topic: function () {
+      var params = { salutation: "Hello", place: "World" };
+      return i18n.format("%(salutation)s %(place)s!", params, true);
+    },
+    "was interpolated": function (err, str) {
+      assert.equal(str, "Hello World!");
+    }
+  }
+});
+
+suite.addBatch({
+  "format a string without interpolation": {
+    topic: function () {
+      return i18n.format("Hello World!");
+    },
+    "was interpolated": function (err, str) {
+      assert.equal(str, "Hello World!");
+    }
+  },
+  "format a null": {
+    topic: function () {
+      return i18n.format(null);
+    },
+    "was interpolated": function (err, str) {
+      assert.equal(str, "");
+    }
+  }
+});
+
+// run or export the suite.
+if (process.argv[1] === __filename) suite.run();
+else suite.export(module);