context: Move scheduler actions to an Enum

Also add helpers for the cli to be able to represent 'FastEnum' directly

1 files changed, 16 insertions, 1 deletions

diff --git a/src/buildstream/_frontend/cli.py b/src/buildstream/_frontend/cli.py
index 12b9439cf..5de02918f 100644
--- a/src/buildstream/_frontend/cli.py
+++ b/src/buildstream/_frontend/cli.py
@@ -10,10 +10,25 @@ from .. import _yaml
 from .._exceptions import BstError, LoadError, AppError
 from .._versions import BST_FORMAT_VERSION
 from .complete import main_bashcomplete, complete_path, CompleteUnhandled
+from ..types import _SchedulerErrorAction
 from ..utils import _get_compression, UtilError
 
 
 ##################################################################
+#              Helper classes and methods for Click              #
+##################################################################
+
+class FastEnumType(click.Choice):
+
+    def __init__(self, enum):
+        self._enum = enum
+        super().__init__(enum.values())
+
+    def convert(self, value, param, ctx):
+        return self._enum(super().convert(value, param, ctx))
+
+
+##################################################################
 #            Override of click's main entry point                #
 ##################################################################
 
@@ -234,7 +249,7 @@ def print_version(ctx, param, value):
               type=click.Path(file_okay=False, readable=True),
               help="Project directory (default: current directory)")
 @click.option('--on-error', default=None,
-              type=click.Choice(['continue', 'quit', 'terminate']),
+              type=FastEnumType(_SchedulerErrorAction),
               help="What to do when an error is encountered")
 @click.option('--fetchers', type=click.INT, default=None,
               help="Maximum simultaneous download tasks")