Ensure `--deps=none` option works for `bst checkout`

Currently, `bst checkout --deps none` command always produces empty
output. Fix this issue and add regression test for the same.

- element_enums.py: Add Scope.NONE.

- element.py: Ensure Scope.NONE works correctly in addition to
  Scope.RUN/Scope.ALL in Element.dependencies() and Element.search().

- tests/frontend/buildcheckout.py: Fix tests for `--deps none`.

Fixes #670.

1 files changed, 8 insertions, 12 deletions

diff --git a/tests/frontend/buildcheckout.py b/tests/frontend/buildcheckout.py
index 1299fa190..d43bac863 100644
--- a/tests/frontend/buildcheckout.py
+++ b/tests/frontend/buildcheckout.py
@@ -90,9 +90,10 @@ def test_build_invalid_suffix_dep(datafiles, cli, strict, hardlinks):
 def test_build_checkout_deps(datafiles, cli, deps):
     project = os.path.join(datafiles.dirname, datafiles.basename)
     checkout = os.path.join(cli.directory, 'checkout')
+    element_name = "checkout-deps.bst"
 
     # First build it
-    result = cli.run(project=project, args=['build', 'target.bst'])
+    result = cli.run(project=project, args=['build', element_name])
     result.assert_success()
 
     # Assert that after a successful build, the builddir is empty
@@ -101,20 +102,15 @@ def test_build_checkout_deps(datafiles, cli, deps):
     assert not os.listdir(builddir)
 
     # Now check it out
-    result = cli.run(project=project, args=['checkout', 'target.bst', '--deps', deps, checkout])
+    result = cli.run(project=project, args=['checkout', element_name, '--deps', deps, checkout])
     result.assert_success()
 
-    # Check that the executable hello file is found in the checkout
-    filename = os.path.join(checkout, 'usr', 'bin', 'hello')
-
-    if deps == "run":
-        assert os.path.exists(filename)
-    else:
-        assert not os.path.exists(filename)
-
-    # Check that the executable hello file is found in the checkout
-    filename = os.path.join(checkout, 'usr', 'include', 'pony.h')
+    # Verify output of this element
+    filename = os.path.join(checkout, 'etc', 'buildstream', 'config')
+    assert os.path.exists(filename)
 
+    # Verify output of this element's runtime dependencies
+    filename = os.path.join(checkout, 'usr', 'bin', 'hello')
     if deps == "run":
         assert os.path.exists(filename)
     else: