1 files changed, 34 insertions, 0 deletions
diff --git a/tests/frontend/main.py b/tests/frontend/main.py
new file mode 100644
index 000000000..9ba552c60
--- /dev/null
+++ b/tests/frontend/main.py
@@ -0,0 +1,34 @@
+from buildstream._frontend.main import prefix_choice_value_proc
+
+import pytest
+import click
+
+
+def test_prefix_choice_value_proc_full_match():
+    value_proc = prefix_choice_value_proc(['foo', 'bar', 'baz'])
+
+    assert("foo" == value_proc("foo"))
+    assert("bar" == value_proc("bar"))
+    assert("baz" == value_proc("baz"))
+
+
+def test_prefix_choice_value_proc_prefix_match():
+    value_proc = prefix_choice_value_proc(['foo'])
+
+    assert ("foo" == value_proc("f"))
+
+
+def test_prefix_choice_value_proc_ambigous_match():
+    value_proc = prefix_choice_value_proc(['bar', 'baz'])
+
+    assert ("bar" == value_proc("bar"))
+    assert ("baz" == value_proc("baz"))
+    with pytest.raises(click.UsageError):
+        value_proc("ba")
+
+
+def test_prefix_choice_value_proc_value_not_in_choices():
+    value_proc = prefix_choice_value_proc(['bar', 'baz'])
+
+    with pytest.raises(click.UsageError):
+        value_proc("foo")