Add in the ability to have arbitrary arguments. (#7)

That is, add the ability to have arbitrary colcon arguments.

Hidden in this refactor is a change in the default arguments
used for packages.  That is, if packages are specified, the
default is now to use --packages-above-and-dependencies for
builds and --packages-above for tests.  If --only-fixes-test
is specified (a new flag), the old behavior of using
--packages-up-to for build and --packages-select for test is
used.  Arguably this reflects our current best practice in
ROS 2, where we want to make sure all packages that depend on
this change are tested as well.

Signed-off-by: Chris Lalancette <clalancette@openrobotics.org>

Author: clalancette

ros_github_scripts/ci_for_pr.py

@@ -307,6 +307,15 @@ def parse_args():
     parser.add_argument(
         '-c', '--comment', action='store_true',
         help='Automatically post a comment on the PRs being built, containing relevant content.')
+    parser.add_argument(
+        '--only-fixes-test', action='store_true',
+        help='The fix being tested only fixes a test, which causes CI to be shorter')
+    parser.add_argument(
+        '--colcon-build-args', type=str, default='',
+        help='Arbitrary colcon arguments to specify to build; must be specified with -b')
+    parser.add_argument(
+        '--colcon-test-args', type=str, default='',
+        help='Arbitrary colcon arguments to specify to test; must be specified with -b')
     return parser.parse_args()
 
 
@@ -328,12 +337,19 @@ def main():
     gist = create_ci_gist(github_instance, chosen_pulls, parsed.target)
     gist_url = gist.files['ros2.repos'].raw_url
 
-    extra_build_args = ''
-    extra_test_args = ''
+    if not parsed.build and (parsed.colcon_build_args or parsed.colcon_test_args):
+        panic('colcon build or test args can only be specified when doing a build')
+
+    extra_build_args = parsed.colcon_build_args
+    extra_test_args = parsed.colcon_test_args
     if parsed.packages:
         packages_changed = ' '.join(parsed.packages)
-        extra_build_args = f'--packages-up-to {packages_changed}'
-        extra_test_args = f'--packages-select {packages_changed}'
+        if parsed.only_fixes_test:
+            extra_build_args += f' --packages-up-to {packages_changed}'
+            extra_test_args += f' --packages-select {packages_changed}'
+        else:
+            extra_build_args += f' --packages-above-and-dependencies {packages_changed}'
+            extra_test_args += f' --packages-above {packages_changed}'
 
     comment_texts = []
     comment_texts.append(