diff -r 000000000000 -r 6474c204b198 dom/datastore/tests/file_app.sjs
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/datastore/tests/file_app.sjs	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,56 @@
+var gBasePath = "tests/dom/datastore/tests/";
+
+function handleRequest(request, response) {
+  var query = getQuery(request);
+
+  var testToken = '';
+  if ('testToken' in query) {
+    testToken = query.testToken;
+  }
+
+  var template = 'file_app.template.webapp';
+  if ('template' in query) {
+    template = query.template;
+  }
+  var template = gBasePath + template;
+  response.setHeader("Content-Type", "application/x-web-app-manifest+json", false);
+  response.write(readTemplate(template).replace(/TESTTOKEN/g, testToken));
+}
+
+// Copy-pasted incantations. There ought to be a better way to synchronously read
+// a file into a string, but I guess we're trying to discourage that.
+function readTemplate(path) {
+  var file = Components.classes["@mozilla.org/file/directory_service;1"].
+                        getService(Components.interfaces.nsIProperties).
+                        get("CurWorkD", Components.interfaces.nsILocalFile);
+  var fis  = Components.classes['@mozilla.org/network/file-input-stream;1'].
+                        createInstance(Components.interfaces.nsIFileInputStream);
+  var cis = Components.classes["@mozilla.org/intl/converter-input-stream;1"].
+                       createInstance(Components.interfaces.nsIConverterInputStream);
+  var split = path.split("/");
+  for(var i = 0; i < split.length; ++i) {
+    file.append(split[i]);
+  }
+  fis.init(file, -1, -1, false);
+  cis.init(fis, "UTF-8", 0, 0);
+
+  var data = "";
+  let (str = {}) {
+    let read = 0;
+    do {
+      read = cis.readString(0xffffffff, str); // read as much as we can and put it in str.value
+      data += str.value;
+    } while (read != 0);
+  }
+  cis.close();
+  return data;
+}
+
+function getQuery(request) {
+  var query = {};
+  request.queryString.split('&').forEach(function (val) {
+    var [name, value] = val.split('=');
+    query[name] = unescape(value);
+  });
+  return query;
+}