Checkout to default dir if no tar or directory:becky/artifact_checkout_directory

When neither --tar nor --directory are provided,
bst artifact checkout will no longer error out.
Defaults to a suitable directory, consistent with bst workspace open.
Test for new feature has been added

2 files changed, 24 insertions, 5 deletions

diff --git a/src/buildstream/_frontend/cli.py b/src/buildstream/_frontend/cli.py
index 1f5d500a8..8fd834825 100644
--- a/src/buildstream/_frontend/cli.py
+++ b/src/buildstream/_frontend/cli.py
@@ -991,10 +991,6 @@ def artifact_checkout(app, force, deps, integrate, hardlinks, tar, pull_, direct
         click.echo("ERROR: options --hardlinks and --tar conflict", err=True)
         sys.exit(-1)
 
-    if tar is None and directory is None:
-        click.echo("ERROR: One of --directory or --tar must be provided", err=True)
-        sys.exit(-1)
-
     if tar is not None and directory is not None:
         click.echo("ERROR: options --directory and --tar conflict", err=True)
         sys.exit(-1)
@@ -1003,7 +999,12 @@ def artifact_checkout(app, force, deps, integrate, hardlinks, tar, pull_, direct
         location = tar
         tar = True
     else:
-        location = os.getcwd() if directory is None else directory
+        if directory is None:
+            location = os.path.abspath(os.path.join(os.getcwd(), element))
+        else:
+            location = directory
+        if location[-4:] == '.bst':
+            location = location[:-4]
         tar = False
 
     if deps == "build":
diff --git a/tests/frontend/buildcheckout.py b/tests/frontend/buildcheckout.py
index d3eec0d21..4e651d70d 100644
--- a/tests/frontend/buildcheckout.py
+++ b/tests/frontend/buildcheckout.py
@@ -233,6 +233,24 @@ def test_build_checkout_tarball(datafiles, cli):
 
 
 @pytest.mark.datafiles(DATA_DIR)
+def test_build_checkout_no_tar_no_directory(datafiles, cli, tmpdir):
+    project = str(datafiles)
+
+    result = cli.run(project=project, args=['build', 'target.bst'])
+    result.assert_success()
+
+    checkout_args = ['artifact', 'checkout', 'target.bst']
+
+    runtestdir = os.path.join(tmpdir.dirname, tmpdir.basename)
+    result = cli.run(cwd=runtestdir, project=project, args=checkout_args)
+    result.assert_success()
+    filename = os.path.join(runtestdir, 'target', 'usr', 'bin', 'hello')
+    assert os.path.exists(filename)
+    filename = os.path.join(runtestdir, 'target', 'usr', 'include', 'pony.h')
+    assert os.path.exists(filename)
+
+
+@pytest.mark.datafiles(DATA_DIR)
 def test_build_checkout_tarball_stdout(datafiles, cli):
     project = str(datafiles)
     tarball = os.path.join(cli.directory, 'tarball.tar')