Finished test_passwords.js, although it raises a number of strict warnings.

services/sync/tests/unit/head_first.js

@@ -164,6 +164,7 @@ function FakeDAVService(contents) {
 
 FakeDAVService.prototype = {
   PUT: function fake_PUT(path, data, onComplete) {
+    Log4Moz.Service.rootLogger.info("Putting " + path);
     this.fakeContents[path] = data;
     makeFakeAsyncFunc({status: 200}).async(this, onComplete);
   },

services/sync/tests/unit/test_passwords.js

@@ -15,7 +15,8 @@ function run_test() {
   var fts = new FakeTimerService();
   var logStats = initTestLogging();
 
-  ID.set('Engine:PBE:default', new Identity('Mozilla Services Encryption Passphrase', 'foo'));
+  ID.set('Engine:PBE:default',
+         new Identity('Mozilla Services Encryption Passphrase', 'foo'));
 
   // The JS module we're testing, with all members exposed.
   var passwords = loadInSandbox("resource://weave/engines/passwords.js");
@@ -40,6 +41,14 @@ function run_test() {
     return {exists: function() {return false;}};
   };
 
+  Utils.open = function fake_open(file, mode) {
+    let fakeStream = {
+      writeString: function(data) {Log4Moz.Service.rootLogger.debug(data);},
+      close: function() {}
+    };
+    return [fakeStream];
+  };
+
   // Ensure that _hashLoginInfo() works.
   var fakeUserHash = passwords._hashLoginInfo(fakeUser);
   do_check_eq(typeof fakeUserHash, 'string');