pmbootstrap init: only display UIs for device arch (MR 1937)

Hide user interfaces that are not available for the selected device's
architecture.

Closes #1790

test/test_helpers_ui.py

@@ -0,0 +1,32 @@
+# Copyright 2020 Oliver Smith
+# SPDX-License-Identifier: GPL-3.0-or-later
+import pytest
+import sys
+
+import pmb_test
+import pmb_test.const
+import pmb.helpers.logging
+import pmb.helpers.ui
+
+
+@pytest.fixture
+def args(tmpdir, request):
+    import pmb.parse
+    cfg = f"{pmb_test.const.testdata}/channels.cfg"
+    sys.argv = ["pmbootstrap.py", "--config-channels", cfg, "init"]
+    args = pmb.parse.arguments()
+    args.log = args.work + "/log_testsuite.txt"
+    pmb.helpers.logging.init(args)
+    request.addfinalizer(args.logfd.close)
+    return args
+
+
+def test_helpers_ui(args):
+    """ Test the UIs returned by pmb.helpers.ui.list() with a testdata pmaports
+        dir. That test dir has a plasma-mobile UI, which is disabled for armhf,
+        so it must not be returned when querying the UI list for armhf. """
+    args.aports = f"{pmb_test.const.testdata}/helpers_ui/pmaports"
+    func = pmb.helpers.ui.list
+    assert func(args, "armhf") == [("none", "No graphical environment")]
+    assert func(args, "x86_64") == [("none", "No graphical environment"),
+                                    ("plasma-mobile", "cool pkgdesc")]