milo: Enable Swarming LogDog log loading.

milo/appengine/swarming/html.go

 // Copyright 2015 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 swarming
 
 import (
         "net/http"
         "os"
 
@@ skipping 35 matching lines @@
                         Message: "unregistered Swarming host",
                         Code:    http.StatusNotFound,
                 }
         }
 }
 
 // Log is for fetching logs from swarming.
 type Log struct{}
 
 // Build is for deciphering recipe builds from swarming based off of logs.
-type Build struct{}
+type Build struct {
+        // bl is the buildLoader to use. A zero value is suitable for production, but
+        // this can be overridden for testing.
+        bl buildLoader
+}
 
 // GetTemplateName for Log returns the template name for log pages.
 func (l Log) GetTemplateName(t settings.Theme) string {
         return "log.html"
 }
 
 // Render writes the build log to the given response writer.
 func (l Log) Render(c context.Context, r *http.Request, p httprouter.Params) (*templates.Args, error) {
         id := p.ByName("id")
         if id == "" {
@@ skipping 41 matching lines @@
                         Message: "No id",
                         Code:    http.StatusBadRequest,
                 }
         }
 
         sf, err := getSwarmingService(c, getSwarmingHost(r))
         if err != nil {
                 return nil, convertErr(err)
         }
 
-        result, err := swarmingBuildImpl(c, sf, r.URL.String(), id)
+        result, err := b.bl.swarmingBuildImpl(c, sf, r.URL.String(), id)
         if err != nil {
                 return nil, convertErr(err)
         }
 
         // Render into the template
         args := &templates.Args{
                 "Build": result,
         }
         return args, nil
 }
 
 func convertErr(err error) error {
         if isAPINotFound(err) || os.IsNotExist(err) {
                 return &miloerror.Error{
                         Message: err.Error(),
                         Code:    http.StatusNotFound,
                 }
         }
         return err
 }
 
 // isAPINotFound returns true if err is a HTTP 404 API response.
 func isAPINotFound(err error) bool {
         if apiErr, ok := err.(*googleapi.Error); ok && apiErr.Code == http.StatusNotFound {
                 return true
         }
 
         return false
 }