fietsupdater: better help behaviour

This does two things:
1. fietsupdate update --help works (before it errored because the
   required argument is not given)
2. fietsupdate help works (like git help ...)

1 files changed, 53 insertions, 23 deletions

diff --git a/fietsboek/updater/cli.py b/fietsboek/updater/cli.py
index 38297d7..6a59100 100644
--- a/fietsboek/updater/cli.py
+++ b/fietsboek/updater/cli.py
@@ -13,6 +13,20 @@ from pyramid.paster import setup_logging
 from . import Updater
 
 
+# We keep this as a separate option that is added to each subcommand as Click
+# (unlike argparse) cannot handle "--help" without the required arguments of
+# the parent (so "fietsupdate update --help" would error out)
+# See also
+# https://github.com/pallets/click/issues/295
+# https://github.com/pallets/click/issues/814
+config_option = click.option(
+    "-c", "--config",
+    type=click.Path(exists=True, dir_okay=False),
+    required=True,
+    help="Path to the Fietsboek configuration file",
+)
+
+
 def user_confirm():
     click.secho("Warning:", fg="yellow")
     click.echo(
@@ -23,29 +37,24 @@ def user_confirm():
     click.confirm("Proceed?", abort=True)
 
 
-@click.group(help=__doc__)
-@click.option(
-    "-c", "--config",
-    type=click.Path(exists=True, dir_okay=False),
-    required=True,
-    help="Path to the Fietsboek configuration file",
+@click.group(
+    help=__doc__,
+    context_settings={'help_option_names': ['-h', '--help']},
 )
-@click.pass_context
-def cli(ctx, config):
-    ctx.ensure_object(dict)
-    setup_logging(config)
-    ctx.obj["INIFILE"] = config
+def cli():
+    """CLI main entry point."""
+    pass
 
 
 @cli.command("update")
+@config_option
 @click.option(
     "-f", "--force",
     is_flag=True,
     help="Skip the safety question and just run the update",
 )
-@click.argument("VERSION", required=False)
-@click.pass_context
-def update(ctx, version, force):
+@click.argument("version", required=False)
+def update(config, version, force):
     """Run the update process.
 
     Make sure to consult the documentation and ensure that you have a backup
@@ -54,7 +63,7 @@ def update(ctx, version, force):
     VERSION specifies the version you want to update to. Leave empty to choose
     the latest version.
     """
-    updater = Updater(ctx.obj["INIFILE"])
+    updater = Updater(config)
     updater.load()
     if version and not updater.exists(version):
         click.secho("Revision not found", fg="red")
@@ -76,14 +85,14 @@ def update(ctx, version, force):
 
 
 @cli.command("downgrade")
+@config_option
 @click.option(
     "-f", "--force",
     is_flag=True,
     help="Skip the safety question and just run the downgrade",
 )
-@click.argument("VERSION")
-@click.pass_context
-def downgrade(ctx, version, force):
+@click.argument("version")
+def downgrade(config, version, force):
     """Run the downgrade process.
 
     Make sure to consult the documentation and ensure that you have a backup
@@ -91,7 +100,7 @@ def downgrade(ctx, version, force):
 
     VERSION specifies the version you want to downgrade to.
     """
-    updater = Updater(ctx.obj["INIFILE"])
+    updater = Updater(config)
     updater.load()
     if version and not updater.exists(version):
         click.secho("Revision not found", fg="red")
@@ -106,10 +115,10 @@ def downgrade(ctx, version, force):
     click.secho(f"Downgrade succeeded, version: {version_str}", fg="green")
 
 
-@cli.command("revision")
-@click.argument("REVISION_ID", required=False)
-@click.pass_context
-def revision(ctx, revision_id):
+@cli.command("revision", hidden=True)
+@config_option
+@click.argument("revision_id", required=False)
+def revision(config, revision_id):
     """Create a new revision.
 
     This automatically populates the revision dependencies and alembic
@@ -133,5 +142,26 @@ def revision(ctx, revision_id):
     click.echo(f"Revision saved to {filename}")
 
 
+@cli.command("help", hidden=True)
+@click.pass_context
+@click.argument("subcommand", required=False)
+def help(ctx, subcommand):
+    """Shows the help for a given subcommand.
+
+    This is equivalent to using the --help option.
+    """
+    if not subcommand:
+        click.echo(cli.get_help(ctx.parent))
+        return
+    cmd = cli.get_command(ctx, subcommand)
+    if cmd is None:
+        click.echo(f"Error: Command {subcommand} not found")
+    else:
+        # Create a new context so that the usage shows "fietsboek subcommand"
+        # instead of "fietsboek help"
+        with click.Context(cmd, ctx.parent, subcommand) as subcontext:
+            click.echo(cmd.get_help(subcontext))
+
+
 if __name__ == "__main__":
     cli()