cli.py: Make source checkout more consistent with artifact checkout

This MR changes the behaviour of source checkout so that it is more
like artifact checkout. That is, a --directory option can be provided,
rather than a mandatory LOCATION.

In addition to this, the --tar option is no longer a boolean flag,
rather it expects a tarfile name (just like artifact checkout)

The appropriate tests have also been altered so that they support
the new API

1 files changed, 15 insertions, 12 deletions

diff --git a/src/buildstream/_frontend/cli.py b/src/buildstream/_frontend/cli.py
index 631eff7d3..9fa482666 100644
--- a/src/buildstream/_frontend/cli.py
+++ b/src/buildstream/_frontend/cli.py
@@ -807,28 +807,31 @@ def source_track(app, elements, deps, except_, cross_junctions):
 @click.option('--deps', '-d', default='none', show_default=True,
               type=click.Choice(['build', 'none', 'run', 'all']),
               help='The dependencies whose sources to checkout')
-@click.option('--tar', 'tar', is_flag=True,
-              help='Create a tarball from the element\'s sources instead of a '
-                   'file tree.')
+@click.option('--tar', default=None, metavar='LOCATION',
+              type=click.Path(),
+              help="Create a tarball containing the sources instead "
+                   "of a file tree.")
 @click.option('--include-build-scripts', 'build_scripts', is_flag=True)
+@click.option('--directory', default='source-checkout',
+              type=click.Path(file_okay=False),
+              help="The directory to checkout the sources to")
 @click.argument('element', required=False, type=click.Path(readable=False))
-@click.argument('location', type=click.Path(), required=False)
 @click.pass_obj
-def source_checkout(app, element, location, force, deps, except_,
+def source_checkout(app, element, directory, force, deps, except_,
                     tar, build_scripts):
     """Checkout sources of an element to the specified location
 
     When this command is executed from a workspace directory, the default
     is to checkout the sources of the workspace element.
     """
-    if not element and not location:
-        click.echo("ERROR: LOCATION is not specified", err=True)
+
+    if tar and directory != "source-checkout":
+        click.echo("ERROR: options --directory and --tar conflict", err=True)
         sys.exit(-1)
 
-    if element and not location:
-        # Nasty hack to get around click's optional args
-        location = element
-        element = None
+    # Set the location depending on whether --tar/--directory were specified
+    # Note that if unset, --directory defaults to "source-checkout"
+    location = tar if tar else directory
 
     with app.initialized():
         if not element:
@@ -841,7 +844,7 @@ def source_checkout(app, element, location, force, deps, except_,
                                    force=force,
                                    deps=deps,
                                    except_targets=except_,
-                                   tar=tar,
+                                   tar=bool(tar),
                                    include_build_scripts=build_scripts)