Fix teacher sessionless play; uses default campaign levels

Fix typo

Fix race condition with loading next level

Return an empty object for next level instead of an error;
Supermodel has a race condition when some of the models fail to load,
when we override an error response as "success".

Fix next level spec

Remove comment per Scott's request

app/models/Classroom.coffee

@@ -82,9 +82,10 @@ module.exports = class Classroom extends CocoModel
     return stats
 
   fetchForCourseInstance: (courseInstanceID, options={}) ->
+    return unless courseInstanceID
     CourseInstance = require 'models/CourseInstance'
     courseInstance = if _.isString(courseInstanceID) then new CourseInstance({_id:courseInstanceID}) else courseInstanceID
     options = _.extend(options, {
       url: _.result(courseInstance, 'url') + '/classroom'
     })
-    @fetch(options)
+    @fetch(options)

app/models/Level.coffee

@@ -252,6 +252,9 @@ module.exports = class Level extends CocoModel
   isLadder: ->
     return @get('type')?.indexOf('ladder') > -1
 
-  fetchNextForCourse: (levelOriginalID, courseInstanceID, options={}) ->
-    options.url = "/db/course_instance/#{courseInstanceID}/levels/#{levelOriginalID}/next"
-    @fetch(options)
+  fetchNextForCourse: ({ levelOriginalID, courseInstanceID, courseID }, options={}) ->
+    if courseInstanceID
+      options.url = "/db/course_instance/#{courseInstanceID}/levels/#{levelOriginalID}/next"
+    else
+      options.url = "/db/course/#{courseID}/levels/#{levelOriginalID}/next"
+    @fetch(options)

app/models/User.coffee

@@ -69,7 +69,7 @@ module.exports = class User extends CocoModel
   isSessionless: ->
     # TODO: Fix old users who got mis-tagged as teachers
     # TODO: Should this just be isTeacher, eventually?
-    me.isTeacher() and utils.getQueryVariable('course', false)
+    Boolean(me.isTeacher() and utils.getQueryVariable('course', false))
 
   setRole: (role, force=false) ->
     return if me.isAdmin()

app/views/play/level/modal/CourseVictoryModal.coffee

@@ -29,9 +29,9 @@ module.exports = class CourseVictoryModal extends ModalView
     @newItems = new ThangTypes()
     @newHeroes = new ThangTypes()
     
-    @classroom = new Classroom()
-    @supermodel.trackRequest(@classroom.fetchForCourseInstance(@courseInstanceID))
-
+    if @courseInstanceID
+      @classroom = new Classroom()
+      @supermodel.trackRequest(@classroom.fetchForCourseInstance(@courseInstanceID))
     @achievements = options.achievements
     if not @achievements
       @achievements = new Achievements()
@@ -43,7 +43,7 @@ module.exports = class CourseVictoryModal extends ModalView
 
     @playSound 'victory'
     @nextLevel = new Level()
-    @nextLevelRequest = @supermodel.trackRequest @nextLevel.fetchNextForCourse(@level.get('original'), @courseInstanceID)
+    @nextLevelRequest = @supermodel.trackRequest @nextLevel.fetchNextForCourse({ levelOriginalID: @level.get('original'), @courseInstanceID, @courseID })
 
     @course = options.course
     if @courseID and not @course

server/middleware/course-instances.coffee

@@ -96,7 +96,7 @@ module.exports =
       throw new errors.NotFound('Level original ObjectId not found in Classroom courses')
     
     if not nextLevelOriginal
-      throw new errors.NotFound('No more levels in that course')
+      res.status(200).send({})
       
     dbq = Level.findOne({original: mongoose.Types.ObjectId(nextLevelOriginal)})
     dbq.sort({ 'version.major': -1, 'version.minor': -1 })
@@ -122,4 +122,4 @@ module.exports =
 
     classroom = classroom.toObject({req: req})
 
-    res.status(200).send(classroom)
+    res.status(200).send(classroom)

server/middleware/courses.coffee

@@ -0,0 +1,51 @@
+errors = require '../commons/errors'
+wrap = require 'co-express'
+database = require '../commons/database'
+mongoose = require 'mongoose'
+Campaign = require '../models/Campaign'
+CourseInstance = require '../models/CourseInstance'
+Classroom = require '../models/Classroom'
+Course = require '../models/Course'
+User = require '../models/User'
+Level = require '../models/Level'
+parse = require '../commons/parse'
+
+module.exports =
+  fetchNextLevel: wrap (req, res) ->
+    levelOriginal = req.params.levelOriginal
+    if not database.isID(levelOriginal)
+      throw new errors.UnprocessableEntity('Invalid level original ObjectId')
+    
+    course = yield database.getDocFromHandle(req, Course)
+    if not course
+      throw new errors.NotFound('Course Instance not found.')
+      
+    campaign = yield Campaign.findById course.get('campaignID')
+    if not campaign
+      throw new errors.NotFound('Campaign not found.')
+    
+    levels = _.values(campaign.get('levels'))
+    levels = _.sortBy(levels, 'campaignIndex')
+    
+    nextLevelOriginal = null
+    foundLevelOriginal = false
+    for level, index in levels
+      if level.original.toString() is levelOriginal
+        foundLevelOriginal = true
+        nextLevelOriginal = levels[index+1]?.original
+        break
+    
+    if not foundLevelOriginal
+      throw new errors.NotFound('Level original ObjectId not found in that course')
+    
+    if not nextLevelOriginal
+      res.status(200).send({})
+      
+    dbq = Level.findOne({original: mongoose.Types.ObjectId(nextLevelOriginal)})
+    
+    
+    dbq.sort({ 'version.major': -1, 'version.minor': -1 })
+    dbq.select(parse.getProjectFromReq(req))
+    level = yield dbq
+    level = level.toObject({req: req})
+    res.status(200).send(level)

server/middleware/index.coffee

@@ -5,6 +5,7 @@ module.exports =
   campaigns: require './campaigns'
   codelogs: require './codelogs'
   courseInstances: require './course-instances'
+  courses: require './courses'
   files: require './files'
   named: require './named'
   patchable: require './patchable'

server/routes/index.coffee

@@ -59,6 +59,7 @@ module.exports.setup = (app) ->
   Course = require '../models/Course'
   app.get('/db/course', mw.rest.get(Course))
   app.get('/db/course/:handle', mw.rest.getByHandle(Course))
+  app.get('/db/course/:handle/levels/:levelOriginal/next', mw.courses.fetchNextLevel)
   
   app.get('/db/course_instance/:handle/levels/:levelOriginal/next', mw.courseInstances.fetchNextLevel)
   app.post('/db/course_instance/:handle/members', mw.auth.checkLoggedIn(), mw.courseInstances.addMembers)

spec/server/functional/course_instance.spec.coffee

@@ -315,9 +315,10 @@ describe 'GET /db/course_instance/:handle/levels/:levelOriginal/next', ->
     expect(res.body.original).toBe(@levelB.original.toString())
     done()
     
-  it 'returns 404 if the given level is the last level in its course', utils.wrap (done) ->
+  it 'returns empty object if the given level is the last level in its course', utils.wrap (done) ->
     [res, body] = yield request.getAsync { uri: utils.getURL("/db/course_instance/#{@courseInstanceA.id}/levels/#{@levelB.id}/next"), json: true }
-    expect(res.statusCode).toBe(404)
+    expect(res.statusCode).toBe(200)
+    expect(res.body).toEqual({})
     done()
 
   it 'returns 404 if the given level is not in the course instance\'s course', utils.wrap (done) ->
@@ -363,4 +364,4 @@ describe 'GET /db/course_instance/:handle/classroom', ->
     yield utils.loginUser @user
     [res, body] = yield request.getAsync(@url, {json: true})
     expect(res.statusCode).toBe(403)
-    done()
+    done()