Add function to calculate unique prefix of two strings

1 files changed, 20 insertions, 1 deletions

diff --git a/test/test_common.py b/test/test_common.py
index d7bc2b8b..b6560fc9 100644
--- a/test/test_common.py
+++ b/test/test_common.py
@@ -11,7 +11,7 @@ from poezio.common import (_datetime_tuple as datetime_tuple, get_utc_time,
                            get_local_time, shell_split, _find_argument_quoted
                            as find_argument_quoted, _find_argument_unquoted as
                            find_argument_unquoted, parse_str_to_secs,
-                           parse_secs_to_str, safeJID)
+                           parse_secs_to_str, safeJID, unique_prefix_of)
 
 def test_utc_time():
     delta = timedelta(seconds=-3600)
@@ -63,3 +63,22 @@ def test_parse_secs_to_str():
 def test_safeJID():
     assert safeJID('toto@titi/tata') == JID('toto@titi/tata')
     assert safeJID('toto@…') == JID('')
+
+def test_unique_prefix_of__no_shared_prefix():
+    assert unique_prefix_of("a", "b") == "a"
+    assert unique_prefix_of("foo", "bar") == "f"
+    assert unique_prefix_of("foo", "") == "f"
+
+def test_unique_prefix_of__equal():
+    assert unique_prefix_of("foo", "foo") == "foo"
+
+def test_unique_prefix_of__a_prefix():
+    assert unique_prefix_of("foo", "foobar") == "foo"
+
+def test_unique_prefix_of__b_prefix():
+    assert unique_prefix_of("foobar", "foo") == "foob"
+
+def test_unique_prefix_of__normal_shared_prefix():
+    assert unique_prefix_of("foobar", "foobaz") == "foobar"
+    assert unique_prefix_of("fnord", "funky") == "fn"
+    assert unique_prefix_of("asbestos", "aspergers") == "asb"