The Tor Browser: services/sync/tests/unit/head_http_server.js@b8a032363ba2 (annotated)

services/sync/tests/unit/head_http_server.js@b8a032363ba2 (annotated)

services/sync/tests/unit/head_http_server.js

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 const Cm = Components.manager;
 // Shared logging for all HTTP server functions.
 Cu.import("resource://gre/modules/Log.jsm");
 const SYNC_HTTP_LOGGER = "Sync.Test.Server";
 const SYNC_API_VERSION = "1.1";
 // Use the same method that record.js does, which mirrors the server.
 // The server returns timestamps with 1/100 sec granularity. Note that this is
 // subject to change: see Bug 650435.
 function new_timestamp() {
   return Math.round(Date.now() / 10) / 100;
 }
 function return_timestamp(request, response, timestamp) {
   if (!timestamp) {
     timestamp = new_timestamp();
   }
   let body = "" + timestamp;
   response.setHeader("X-Weave-Timestamp", body);
   response.setStatusLine(request.httpVersion, 200, "OK");
   response.bodyOutputStream.write(body, body.length);
   return timestamp;
 }
 function basic_auth_header(user, password) {
   return "Basic " + btoa(user + ":" + Utils.encodeUTF8(password));
 }
 function basic_auth_matches(req, user, password) {
   if (!req.hasHeader("Authorization")) {
     return false;
   }
   let expected = basic_auth_header(user, Utils.encodeUTF8(password));
   return req.getHeader("Authorization") == expected;
 }
 function httpd_basic_auth_handler(body, metadata, response) {
   if (basic_auth_matches(metadata, "guest", "guest")) {
     response.setStatusLine(metadata.httpVersion, 200, "OK, authorized");
     response.setHeader("WWW-Authenticate", 'Basic realm="secret"', false);
   } else {
     body = "This path exists and is protected - failed";
     response.setStatusLine(metadata.httpVersion, 401, "Unauthorized");
     response.setHeader("WWW-Authenticate", 'Basic realm="secret"', false);
   }
   response.bodyOutputStream.write(body, body.length);
 }
 /*
  * Represent a WBO on the server
  */
 function ServerWBO(id, initialPayload, modified) {
   if (!id) {
     throw "No ID for ServerWBO!";
   }
   this.id = id;
   if (!initialPayload) {
     return;
   }
   if (typeof initialPayload == "object") {
     initialPayload = JSON.stringify(initialPayload);
   }
   this.payload = initialPayload;
   this.modified = modified || new_timestamp();
 }
 ServerWBO.prototype = {
   get data() {
     return JSON.parse(this.payload);
   },
   get: function() {
     return JSON.stringify(this, ["id", "modified", "payload"]);
   },
   put: function(input) {
     input = JSON.parse(input);
     this.payload = input.payload;
     this.modified = new_timestamp();
   },
   delete: function() {
     delete this.payload;
     delete this.modified;
   },
   // This handler sets `newModified` on the response body if the collection
   // timestamp has changed. This allows wrapper handlers to extract information
   // that otherwise would exist only in the body stream.
   handler: function() {
     let self = this;
     return function(request, response) {
       var statusCode = 200;
       var status = "OK";
       var body;
       switch(request.method) {
         case "GET":
           if (self.payload) {
             body = self.get();
           } else {
             statusCode = 404;
             status = "Not Found";
             body = "Not Found";
           }
           break;
         case "PUT":
           self.put(readBytesFromInputStream(request.bodyInputStream));
           body = JSON.stringify(self.modified);
           response.setHeader("Content-Type", "application/json");
           response.newModified = self.modified;
           break;
         case "DELETE":
           self.delete();
           let ts = new_timestamp();
           body = JSON.stringify(ts);
           response.setHeader("Content-Type", "application/json");
           response.newModified = ts;
           break;
       }
       response.setHeader("X-Weave-Timestamp", "" + new_timestamp(), false);
       response.setStatusLine(request.httpVersion, statusCode, status);
       response.bodyOutputStream.write(body, body.length);
     };
   }
 };
 /**
  * Represent a collection on the server. The '_wbos' attribute is a
  * mapping of id -> ServerWBO objects.
  *
  * Note that if you want these records to be accessible individually,
  * you need to register their handlers with the server separately, or use a
  * containing HTTP server that will do so on your behalf.
  *
  * @param wbos
  *        An object mapping WBO IDs to ServerWBOs.
  * @param acceptNew
  *        If true, POSTs to this collection URI will result in new WBOs being
  *        created and wired in on the fly.
  * @param timestamp
  *        An optional timestamp value to initialize the modified time of the
  *        collection. This should be in the format returned by new_timestamp().
  *
  * @return the new ServerCollection instance.
  *
  */
 function ServerCollection(wbos, acceptNew, timestamp) {
   this._wbos = wbos || {};
   this.acceptNew = acceptNew || false;
   /*
    * Track modified timestamp.
    * We can't just use the timestamps of contained WBOs: an empty collection
    * has a modified time.
    */
   this.timestamp = timestamp || new_timestamp();
   this._log = Log.repository.getLogger(SYNC_HTTP_LOGGER);
 }
 ServerCollection.prototype = {
   /**
    * Convenience accessor for our WBO keys.
    * Excludes deleted items, of course.
    *
    * @param filter
    *        A predicate function (applied to the ID and WBO) which dictates
    *        whether to include the WBO's ID in the output.
    *
    * @return an array of IDs.
    */
   keys: function keys(filter) {
     return [id for ([id, wbo] in Iterator(this._wbos))
                if (wbo.payload &&
                    (!filter || filter(id, wbo)))];
   },
   /**
    * Convenience method to get an array of WBOs.
    * Optionally provide a filter function.
    *
    * @param filter
    *        A predicate function, applied to the WBO, which dictates whether to
    *        include the WBO in the output.
    *
    * @return an array of ServerWBOs.
    */
   wbos: function wbos(filter) {
     let os = [wbo for ([id, wbo] in Iterator(this._wbos))
               if (wbo.payload)];
     if (filter) {
       return os.filter(filter);
     }
     return os;
   },
   /**
    * Convenience method to get an array of parsed ciphertexts.
    *
    * @return an array of the payloads of each stored WBO.
    */
   payloads: function () {
     return this.wbos().map(function (wbo) {
       return JSON.parse(JSON.parse(wbo.payload).ciphertext);
     });
   },
   // Just for syntactic elegance.
   wbo: function wbo(id) {
     return this._wbos[id];
   },
   payload: function payload(id) {
     return this.wbo(id).payload;
   },
   /**
    * Insert the provided WBO under its ID.
    *
    * @return the provided WBO.
    */
   insertWBO: function insertWBO(wbo) {
     return this._wbos[wbo.id] = wbo;
   },
   /**
    * Insert the provided payload as part of a new ServerWBO with the provided
    * ID.
    *
    * @param id
    *        The GUID for the WBO.
    * @param payload
    *        The payload, as provided to the ServerWBO constructor.
    * @param modified
    *        An optional modified time for the ServerWBO.
    *
    * @return the inserted WBO.
    */
   insert: function insert(id, payload, modified) {
     return this.insertWBO(new ServerWBO(id, payload, modified));
   },
   /**
    * Removes an object entirely from the collection.
    *
    * @param id
    *        (string) ID to remove.
    */
   remove: function remove(id) {
     delete this._wbos[id];
   },
   _inResultSet: function(wbo, options) {
     return wbo.payload
            && (!options.ids || (options.ids.indexOf(wbo.id) != -1))
            && (!options.newer || (wbo.modified > options.newer));
   },
   count: function(options) {
     options = options || {};
     let c = 0;
     for (let [id, wbo] in Iterator(this._wbos)) {
       if (wbo.modified && this._inResultSet(wbo, options)) {
         c++;
       }
     }
     return c;
   },
   get: function(options) {
     let result;
     if (options.full) {
       let data = [wbo.get() for ([id, wbo] in Iterator(this._wbos))
                             // Drop deleted.
                             if (wbo.modified &&
                                 this._inResultSet(wbo, options))];
       if (options.limit) {
         data = data.slice(0, options.limit);
       }
       // Our implementation of application/newlines.
       result = data.join("\n") + "\n";
       // Use options as a backchannel to report count.
       options.recordCount = data.length;
     } else {
       let data = [id for ([id, wbo] in Iterator(this._wbos))
                      if (this._inResultSet(wbo, options))];
       if (options.limit) {
         data = data.slice(0, options.limit);
       }
       result = JSON.stringify(data);
       options.recordCount = data.length;
     }
     return result;
   },
   post: function(input) {
     input = JSON.parse(input);
     let success = [];
     let failed = {};
     // This will count records where we have an existing ServerWBO
     // registered with us as successful and all other records as failed.
     for each (let record in input) {
       let wbo = this.wbo(record.id);
       if (!wbo && this.acceptNew) {
         this._log.debug("Creating WBO " + JSON.stringify(record.id) +
                         " on the fly.");
         wbo = new ServerWBO(record.id);
         this.insertWBO(wbo);
       }
       if (wbo) {
         wbo.payload = record.payload;
         wbo.modified = new_timestamp();
         success.push(record.id);
       } else {
         failed[record.id] = "no wbo configured";
       }
     }
     return {modified: new_timestamp(),
             success: success,
             failed: failed};
   },
   delete: function(options) {
     let deleted = [];
     for (let [id, wbo] in Iterator(this._wbos)) {
       if (this._inResultSet(wbo, options)) {
         this._log.debug("Deleting " + JSON.stringify(wbo));
         deleted.push(wbo.id);
         wbo.delete();
       }
     }
     return deleted;
   },
   // This handler sets `newModified` on the response body if the collection
   // timestamp has changed.
   handler: function() {
     let self = this;
     return function(request, response) {
       var statusCode = 200;
       var status = "OK";
       var body;
       // Parse queryString
       let options = {};
       for each (let chunk in request.queryString.split("&")) {
         if (!chunk) {
           continue;
         }
         chunk = chunk.split("=");
         if (chunk.length == 1) {
           options[chunk[0]] = "";
         } else {
           options[chunk[0]] = chunk[1];
         }
       }
       if (options.ids) {
         options.ids = options.ids.split(",");
       }
       if (options.newer) {
         options.newer = parseFloat(options.newer);
       }
       if (options.limit) {
         options.limit = parseInt(options.limit, 10);
       }
       switch(request.method) {
         case "GET":
           body = self.get(options);
           // "If supported by the db, this header will return the number of
           // records total in the request body of any multiple-record GET
           // request."
           let records = options.recordCount;
           self._log.info("Records: " + records);
           if (records != null) {
             response.setHeader("X-Weave-Records", "" + records);
           }
           break;
         case "POST":
           let res = self.post(readBytesFromInputStream(request.bodyInputStream));
           body = JSON.stringify(res);
           response.newModified = res.modified;
           break;
         case "DELETE":
           self._log.debug("Invoking ServerCollection.DELETE.");
           let deleted = self.delete(options);
           let ts = new_timestamp();
           body = JSON.stringify(ts);
           response.newModified = ts;
           response.deleted = deleted;
           break;
       }
       response.setHeader("X-Weave-Timestamp",
                          "" + new_timestamp(),
                          false);
       response.setStatusLine(request.httpVersion, statusCode, status);
       response.bodyOutputStream.write(body, body.length);
       // Update the collection timestamp to the appropriate modified time.
       // This is either a value set by the handler, or the current time.
       if (request.method != "GET") {
         this.timestamp = (response.newModified >= 0) ?
                          response.newModified :
                          new_timestamp();
       }
     };
   }
 };
 /*
  * Test setup helpers.
  */
 function sync_httpd_setup(handlers) {
   handlers["/1.1/foo/storage/meta/global"]
       = (new ServerWBO("global", {})).handler();
   return httpd_setup(handlers);
 }
 /*
  * Track collection modified times. Return closures.
  */
 function track_collections_helper() {
   /*
    * Our tracking object.
    */
   let collections = {};
   /*
    * Update the timestamp of a collection.
    */
   function update_collection(coll, ts) {
     _("Updating collection " + coll + " to " + ts);
     let timestamp = ts || new_timestamp();
     collections[coll] = timestamp;
   }
   /*
    * Invoke a handler, updating the collection's modified timestamp unless
    * it's a GET request.
    */
   function with_updated_collection(coll, f) {
     return function(request, response) {
       f.call(this, request, response);
       // Update the collection timestamp to the appropriate modified time.
       // This is either a value set by the handler, or the current time.
       if (request.method != "GET") {
         update_collection(coll, response.newModified)
       }
     };
   }
   /*
    * Return the info/collections object.
    */
   function info_collections(request, response) {
     let body = "Error.";
     switch(request.method) {
       case "GET":
         body = JSON.stringify(collections);
         break;
       default:
         throw "Non-GET on info_collections.";
     }
     response.setHeader("Content-Type", "application/json");
     response.setHeader("X-Weave-Timestamp",
                        "" + new_timestamp(),
                        false);
     response.setStatusLine(request.httpVersion, 200, "OK");
     response.bodyOutputStream.write(body, body.length);
   }
   return {"collections": collections,
           "handler": info_collections,
           "with_updated_collection": with_updated_collection,
           "update_collection": update_collection};
 }
 //===========================================================================//
 // httpd.js-based Sync server.                                               //
 //===========================================================================//
 /**
  * In general, the preferred way of using SyncServer is to directly introspect
  * it. Callbacks are available for operations which are hard to verify through
  * introspection, such as deletions.
  *
  * One of the goals of this server is to provide enough hooks for test code to
  * find out what it needs without monkeypatching. Use this object as your
  * prototype, and override as appropriate.
  */
 let SyncServerCallback = {
   onCollectionDeleted: function onCollectionDeleted(user, collection) {},
   onItemDeleted: function onItemDeleted(user, collection, wboID) {},
   /**
    * Called at the top of every request.
    *
    * Allows the test to inspect the request. Hooks should be careful not to
    * modify or change state of the request or they may impact future processing.
    */
   onRequest: function onRequest(request) {},
 };
 /**
  * Construct a new test Sync server. Takes a callback object (e.g.,
  * SyncServerCallback) as input.
  */
 function SyncServer(callback) {
   this.callback = callback || {__proto__: SyncServerCallback};
   this.server   = new HttpServer();
   this.started  = false;
   this.users    = {};
   this._log     = Log.repository.getLogger(SYNC_HTTP_LOGGER);
   // Install our own default handler. This allows us to mess around with the
   // whole URL space.
   let handler = this.server._handler;
   handler._handleDefault = this.handleDefault.bind(this, handler);
 }
 SyncServer.prototype = {
   server: null,    // HttpServer.
   users:  null,    // Map of username => {collections, password}.
   /**
    * Start the SyncServer's underlying HTTP server.
    *
    * @param port
    *        The numeric port on which to start. A falsy value implies the
    *        default, a randomly chosen port.
    * @param cb
    *        A callback function (of no arguments) which is invoked after
    *        startup.
    */
   start: function start(port, cb) {
     if (this.started) {
       this._log.warn("Warning: server already started on " + this.port);
       return;
     }
     try {
       this.server.start(port);
       let i = this.server.identity;
       this.port = i.primaryPort;
       this.baseURI = i.primaryScheme + "://" + i.primaryHost + ":" +
                      i.primaryPort + "/";
       this.started = true;
       if (cb) {
         cb();
       }
     } catch (ex) {
       _("==========================================");
       _("Got exception starting Sync HTTP server.");
       _("Error: " + Utils.exceptionStr(ex));
       _("Is there a process already listening on port " + port + "?");
       _("==========================================");
       do_throw(ex);
     }
   },
   /**
    * Stop the SyncServer's HTTP server.
    *
    * @param cb
    *        A callback function. Invoked after the server has been stopped.
    *
    */
   stop: function stop(cb) {
     if (!this.started) {
       this._log.warn("SyncServer: Warning: server not running. Can't stop me now!");
       return;
     }
     this.server.stop(cb);
     this.started = false;
   },
   /**
    * Return a server timestamp for a record.
    * The server returns timestamps with 1/100 sec granularity. Note that this is
    * subject to change: see Bug 650435.
    */
   timestamp: function timestamp() {
     return new_timestamp();
   },
   /**
    * Create a new user, complete with an empty set of collections.
    *
    * @param username
    *        The username to use. An Error will be thrown if a user by that name
    *        already exists.
    * @param password
    *        A password string.
    *
    * @return a user object, as would be returned by server.user(username).
    */
   registerUser: function registerUser(username, password) {
     if (username in this.users) {
       throw new Error("User already exists.");
     }
     this.users[username] = {
       password: password,
       collections: {}
     };
     return this.user(username);
   },
   userExists: function userExists(username) {
     return username in this.users;
   },
   getCollection: function getCollection(username, collection) {
     return this.users[username].collections[collection];
   },
   _insertCollection: function _insertCollection(collections, collection, wbos) {
     let coll = new ServerCollection(wbos, true);
     coll.collectionHandler = coll.handler();
     collections[collection] = coll;
     return coll;
   },
   createCollection: function createCollection(username, collection, wbos) {
     if (!(username in this.users)) {
       throw new Error("Unknown user.");
     }
     let collections = this.users[username].collections;
     if (collection in collections) {
       throw new Error("Collection already exists.");
     }
     return this._insertCollection(collections, collection, wbos);
   },
   /**
    * Accept a map like the following:
    * {
    *   meta: {global: {version: 1, ...}},
    *   crypto: {"keys": {}, foo: {bar: 2}},
    *   bookmarks: {}
    * }
    * to cause collections and WBOs to be created.
    * If a collection already exists, no error is raised.
    * If a WBO already exists, it will be updated to the new contents.
    */
   createContents: function createContents(username, collections) {
     if (!(username in this.users)) {
       throw new Error("Unknown user.");
     }
     let userCollections = this.users[username].collections;
     for (let [id, contents] in Iterator(collections)) {
       let coll = userCollections[id] ||
                  this._insertCollection(userCollections, id);
       for (let [wboID, payload] in Iterator(contents)) {
         coll.insert(wboID, payload);
       }
     }
   },
   /**
    * Insert a WBO in an existing collection.
    */
   insertWBO: function insertWBO(username, collection, wbo) {
     if (!(username in this.users)) {
       throw new Error("Unknown user.");
     }
     let userCollections = this.users[username].collections;
     if (!(collection in userCollections)) {
       throw new Error("Unknown collection.");
     }
     userCollections[collection].insertWBO(wbo);
     return wbo;
   },
   /**
    * Delete all of the collections for the named user.
    *
    * @param username
    *        The name of the affected user.
    *
    * @return a timestamp.
    */
   deleteCollections: function deleteCollections(username) {
     if (!(username in this.users)) {
       throw new Error("Unknown user.");
     }
     let userCollections = this.users[username].collections;
     for each (let [name, coll] in Iterator(userCollections)) {
       this._log.trace("Bulk deleting " + name + " for " + username + "...");
       coll.delete({});
     }
     this.users[username].collections = {};
     return this.timestamp();
   },
   /**
    * Simple accessor to allow collective binding and abbreviation of a bunch of
    * methods. Yay!
    * Use like this:
    *
    *   let u = server.user("john");
    *   u.collection("bookmarks").wbo("abcdefg").payload;  // Etc.
    *
    * @return a proxy for the user data stored in this server.
    */
   user: function user(username) {
     let collection       = this.getCollection.bind(this, username);
     let createCollection = this.createCollection.bind(this, username);
     let createContents   = this.createContents.bind(this, username);
     let modified         = function (collectionName) {
       return collection(collectionName).timestamp;
     }
     let deleteCollections = this.deleteCollections.bind(this, username);
     return {
       collection:        collection,
       createCollection:  createCollection,
       createContents:    createContents,
       deleteCollections: deleteCollections,
       modified:          modified
     };
   },
   /*
    * Regular expressions for splitting up Sync request paths.
    * Sync URLs are of the form:
    *   /$apipath/$version/$user/$further
    * where $further is usually:
    *   storage/$collection/$wbo
    * or
    *   storage/$collection
    * or
    *   info/$op
    * We assume for the sake of simplicity that $apipath is empty.
    *
    * N.B., we don't follow any kind of username spec here, because as far as I
    * can tell there isn't one. See Bug 689671. Instead we follow the Python
    * server code.
    *
    * Path: [all, version, username, first, rest]
    * Storage: [all, collection?, id?]
    */
   pathRE: /^\/([0-9]+(?:\.[0-9]+)?)\/([-._a-zA-Z0-9]+)(?:\/([^\/]+)(?:\/(.+))?)?$/,
   storageRE: /^([-_a-zA-Z0-9]+)(?:\/([-_a-zA-Z0-9]+)\/?)?$/,
   defaultHeaders: {},
   /**
    * HTTP response utility.
    */
   respond: function respond(req, resp, code, status, body, headers) {
     resp.setStatusLine(req.httpVersion, code, status);
     for each (let [header, value] in Iterator(headers || this.defaultHeaders)) {
       resp.setHeader(header, value);
     }
     resp.setHeader("X-Weave-Timestamp", "" + this.timestamp(), false);
     resp.bodyOutputStream.write(body, body.length);
   },
   /**
    * This is invoked by the HttpServer. `this` is bound to the SyncServer;
    * `handler` is the HttpServer's handler.
    *
    * TODO: need to use the correct Sync API response codes and errors here.
    * TODO: Basic Auth.
    * TODO: check username in path against username in BasicAuth.
    */
   handleDefault: function handleDefault(handler, req, resp) {
     try {
       this._handleDefault(handler, req, resp);
     } catch (e) {
       if (e instanceof HttpError) {
         this.respond(req, resp, e.code, e.description, "", {});
       } else {
         throw e;
       }
     }
   },
   _handleDefault: function _handleDefault(handler, req, resp) {
     this._log.debug("SyncServer: Handling request: " + req.method + " " + req.path);
     if (this.callback.onRequest) {
       this.callback.onRequest(req);
     }
     let parts = this.pathRE.exec(req.path);
     if (!parts) {
       this._log.debug("SyncServer: Unexpected request: bad URL " + req.path);
       throw HTTP_404;
     }
     let [all, version, username, first, rest] = parts;
     // Doing a float compare of the version allows for us to pretend there was
     // a node-reassignment - eg, we could re-assign from "1.1/user/" to
     // "1.10/user" - this server will then still accept requests with the new
     // URL while any code in sync itself which compares URLs will see a
     // different URL.
     if (parseFloat(version) != parseFloat(SYNC_API_VERSION)) {
       this._log.debug("SyncServer: Unknown version.");
       throw HTTP_404;
     }
     if (!this.userExists(username)) {
       this._log.debug("SyncServer: Unknown user.");
       throw HTTP_401;
     }
     // Hand off to the appropriate handler for this path component.
     if (first in this.toplevelHandlers) {
       let handler = this.toplevelHandlers[first];
       return handler.call(this, handler, req, resp, version, username, rest);
     }
     this._log.debug("SyncServer: Unknown top-level " + first);
     throw HTTP_404;
   },
   /**
    * Compute the object that is returned for an info/collections request.
    */
   infoCollections: function infoCollections(username) {
     let responseObject = {};
     let colls = this.users[username].collections;
     for (let coll in colls) {
       responseObject[coll] = colls[coll].timestamp;
     }
     this._log.trace("SyncServer: info/collections returning " +
                     JSON.stringify(responseObject));
     return responseObject;
   },
   /**
    * Collection of the handler methods we use for top-level path components.
    */
   toplevelHandlers: {
     "storage": function handleStorage(handler, req, resp, version, username, rest) {
       let respond = this.respond.bind(this, req, resp);
       if (!rest || !rest.length) {
         this._log.debug("SyncServer: top-level storage " +
                         req.method + " request.");
         // TODO: verify if this is spec-compliant.
         if (req.method != "DELETE") {
           respond(405, "Method Not Allowed", "[]", {"Allow": "DELETE"});
           return undefined;
         }
         // Delete all collections and track the timestamp for the response.
         let timestamp = this.user(username).deleteCollections();
         // Return timestamp and OK for deletion.
         respond(200, "OK", JSON.stringify(timestamp));
         return undefined;
       }
       let match = this.storageRE.exec(rest);
       if (!match) {
         this._log.warn("SyncServer: Unknown storage operation " + rest);
         throw HTTP_404;
       }
       let [all, collection, wboID] = match;
       let coll = this.getCollection(username, collection);
       switch (req.method) {
         case "GET":
           if (!coll) {
             if (wboID) {
               respond(404, "Not found", "Not found");
               return undefined;
             }
             // *cries inside*: Bug 687299.
             respond(200, "OK", "[]");
             return undefined;
           }
           if (!wboID) {
             return coll.collectionHandler(req, resp);
           }
           let wbo = coll.wbo(wboID);
           if (!wbo) {
             respond(404, "Not found", "Not found");
             return undefined;
           }
           return wbo.handler()(req, resp);
         // TODO: implement handling of X-If-Unmodified-Since for write verbs.
         case "DELETE":
           if (!coll) {
             respond(200, "OK", "{}");
             return undefined;
           }
           if (wboID) {
             let wbo = coll.wbo(wboID);
             if (wbo) {
               wbo.delete();
               this.callback.onItemDeleted(username, collection, wboID);
             }
             respond(200, "OK", "{}");
             return undefined;
           }
           coll.collectionHandler(req, resp);
           // Spot if this is a DELETE for some IDs, and don't blow away the
           // whole collection!
           //
           // We already handled deleting the WBOs by invoking the deleted
           // collection's handler. However, in the case of
           //
           //   DELETE storage/foobar
           //
           // we also need to remove foobar from the collections map. This
           // clause tries to differentiate the above request from
           //
           //  DELETE storage/foobar?ids=foo,baz
           //
           // and do the right thing.
           // TODO: less hacky method.
           if (-1 == req.queryString.indexOf("ids=")) {
             // When you delete the entire collection, we drop it.
             this._log.debug("Deleting entire collection.");
             delete this.users[username].collections[collection];
             this.callback.onCollectionDeleted(username, collection);
           }
           // Notify of item deletion.
           let deleted = resp.deleted || [];
           for (let i = 0; i < deleted.length; ++i) {
             this.callback.onItemDeleted(username, collection, deleted[i]);
           }
           return undefined;
         case "POST":
         case "PUT":
           if (!coll) {
             coll = this.createCollection(username, collection);
           }
           if (wboID) {
             let wbo = coll.wbo(wboID);
             if (!wbo) {
               this._log.trace("SyncServer: creating WBO " + collection + "/" + wboID);
               wbo = coll.insert(wboID);
             }
             // Rather than instantiate each WBO's handler function, do it once
             // per request. They get hit far less often than do collections.
             wbo.handler()(req, resp);
             coll.timestamp = resp.newModified;
             return resp;
           }
           return coll.collectionHandler(req, resp);
         default:
           throw "Request method " + req.method + " not implemented.";
       }
     },
     "info": function handleInfo(handler, req, resp, version, username, rest) {
       switch (rest) {
         case "collections":
           let body = JSON.stringify(this.infoCollections(username));
           this.respond(req, resp, 200, "OK", body, {
             "Content-Type": "application/json"
           });
           return;
         case "collection_usage":
         case "collection_counts":
         case "quota":
           // TODO: implement additional info methods.
           this.respond(req, resp, 200, "OK", "TODO");
           return;
         default:
           // TODO
           this._log.warn("SyncServer: Unknown info operation " + rest);
           throw HTTP_404;
       }
     }
   }
 };
 /**
  * Test helper.
  */
 function serverForUsers(users, contents, callback) {
   let server = new SyncServer(callback);
   for (let [user, pass] in Iterator(users)) {
     server.registerUser(user, pass);
     server.createContents(user, contents);
   }
   server.start();
   return server;
 }