Milo: Increase test coverage for appengine/buildbot

milo/appengine/buildbot/buildinfo_test.go

 // Copyright 2017 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package buildbot
 
 import (
         "testing"
 
         miloProto "github.com/luci/luci-go/common/proto/milo"
@@ skipping 116 matching lines @@
                 biReq := milo.BuildInfoRequest{
                         Build: &milo.BuildInfoRequest_Buildbot{
                                 Buildbot: &milo.BuildInfoRequest_BuildBot{
                                         MasterName:  "foo master",
                                         BuilderName: "bar builder",
                                         BuildNumber: 1337,
                                 },
                         },
                 }
 
+                Convey("Load an invalid build", func() {
+                        _, err := bip.GetBuildInfo(c,
+                                &milo.BuildInfoRequest_BuildBot{
+                                        MasterName:  "foo master",
+                                        BuilderName: "bar builder",
+                                        BuildNumber: 1334,
+                                }, "")
+                        So(err.Error(), ShouldResemble, "rpc error: code = Unauthenticated desc = ")
+                })
+
                 Convey("Can load a BuildBot build by log location.", func() {
                         build.Properties = append(build.Properties, []*buildbotProperty{
                                 {Name: "log_location", Value: "logdog://example.com/testproject/foo/bar/+/baz/annotations"},
                         }...)
                         So(ds.Put(c, &build), ShouldBeNil)
                         testClient.resp = []interface{}{
                                 datagramGetResponse("testproject", "foo/bar", &logdogStep),
                         }
 
                         resp, err := bip.GetBuildInfo(c, biReq.GetBuildbot(), "")
@@ skipping 210 matching lines @@
                                 },
                                 AnnotationStream: &miloProto.LogdogStream{
                                         Server: "example.com",
                                         Prefix: "bb/foo_master/bar_builder/1337",
                                         Name:   "annotations",
                                 },
                         })
                 })
         })
 }