[recipes.py] add missing helpstrings, merge test subcommands into main parser.

recipe_engine/autoroll.py

 # Copyright 2016 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.
 
 from __future__ import print_function
 
 import copy
 import json
 import logging
 import os
@@ skipping 250 matching lines @@
     'picked_roll_details': picked_roll_details,
     'rejected_candidates_count': len(rejected_candidates),
   }
   if verbose_json:
     ret['rejected_candidate_specs'] = [
       package_io.dump_obj(c.package_pb) for c in rejected_candidates]
   return ret
 
 
 def add_subparser(parser):
+  helpstr = 'Roll dependencies of a recipe package forward.'
   autoroll_p = parser.add_parser(
-      'autoroll',
-      help='Roll dependencies of a recipe package forward (implies fetch)')
+    'autoroll', help=helpstr, description=helpstr)
   autoroll_p.add_argument(
-      '--output-json',
-      type=os.path.abspath,
-      help='A json file to output information about the roll to.')
+    '--output-json',
+    type=os.path.abspath,
+    help='A json file to output information about the roll to.')
   autoroll_p.add_argument(
-      '--verbose-json',
-      action='store_true',
-      help=('Emit even more data in the output-json file. '
-            'Requires --output-json.'))
+    '--verbose-json',
+    action='store_true',
+    help=('Emit even more data in the output-json file. '
+          'Requires --output-json.'))
 
   def postprocess_func(parser, args):
+    if args.no_fetch:
+      parser.error('autoroll with --no-fetch does not make sense.')
+
     if args.verbose_json and not args.output_json:
       parser.error('--verbose-json passed without --output-json')
 
   autoroll_p.set_defaults(
     command='autoroll', func=main, postprocess_func=postprocess_func)
 
 
 def main(_package_deps, args):
   config_file = args.package
   repo_root = package.InfraRepoConfig().from_recipes_cfg(config_file.path)
@@ skipping 17 matching lines @@
       # Restore initial state. Since we could be running simulation tests
       # on other revisions, re-run them now as well.
       write_spec_to_disk(context, repo_cfg_block, config_file, package_pb)
       run_simulation_test(repo_root, package_spec.recipes_path, ['train'])
 
   if args.output_json:
     with open(args.output_json, 'w') as f:
       json.dump(results, f, sort_keys=True, indent=2)
 
   return 0