Merge "fix fuzzy search for same-distance case"

cliff/app.py

@@ -9,7 +9,6 @@ import logging
 import logging.handlers
 import os
 import sys
-import operator
 
 from .complete import CompleteCommand
 from .help import HelpAction, HelpCommand
@@ -314,21 +313,22 @@ class App(object):
             prefix = candidate.split(sep)[0]
             # Give prefix match a very good score
             if candidate.startswith(cmd):
-                dist.append((candidate, 0))
+                dist.append((0, candidate))
                 continue
             # Levenshtein distance
-            dist.append((candidate, damerau_levenshtein(cmd, prefix, COST)+1))
-        dist = sorted(dist, key=operator.itemgetter(1, 0))
+            dist.append((damerau_levenshtein(cmd, prefix, COST)+1, candidate))
+
         matches = []
-        i = 0
-        # Find the best similarity
-        while (not dist[i][1]):
-            matches.append(dist[i][0])
-            i += 1
-        best_similarity = dist[i][1]
-        while (dist[i][1] == best_similarity):
-            matches.append(dist[i][0])
-            i += 1
+        match_distance = 0
+        for distance, candidate in sorted(dist):
+            if distance > match_distance:
+                if match_distance:
+                    # we copied all items with minimum distance, we are done
+                    break
+                # we copied all items with distance=0,
+                # now we match all candidates at the minimum distance
+                match_distance = distance
+            matches.append(candidate)
 
         return matches
 

cliff/tests/test_app.py

@@ -13,6 +13,7 @@ from cliff.app import App
 from cliff.command import Command
 from cliff.commandmanager import CommandManager
 from cliff.tests import utils
+from cliff.utils import damerau_levenshtein, COST
 
 
 def make_app(**kwargs):
@@ -448,3 +449,42 @@ def test_list_matching_commands():
     assert "test: 't' is not a test command. See 'test --help'." in output
     assert 'Did you mean one of these?' in output
     assert 'three word command\n  two words\n' in output
+
+
+def test_fuzzy_no_commands():
+    cmd_mgr = CommandManager('cliff.fuzzy')
+    app = App('test', '1.0', cmd_mgr)
+    cmd_mgr.commands = {}
+    matches = app.get_fuzzy_matches('foo')
+    assert matches == []
+
+
+def test_fuzzy_common_prefix():
+    # searched string is a prefix of all commands
+    cmd_mgr = CommandManager('cliff.fuzzy')
+    app = App('test', '1.0', cmd_mgr)
+    cmd_mgr.commands = {}
+    cmd_mgr.add_command('user list', utils.TestCommand)
+    cmd_mgr.add_command('user show', utils.TestCommand)
+    matches = app.get_fuzzy_matches('user')
+    assert matches == ['user list', 'user show']
+
+
+def test_fuzzy_same_distance():
+    # searched string has the same distance to all commands
+    cmd_mgr = CommandManager('cliff.fuzzy')
+    app = App('test', '1.0', cmd_mgr)
+    cmd_mgr.add_command('user', utils.TestCommand)
+    for cmd in cmd_mgr.commands.keys():
+        assert damerau_levenshtein('node', cmd, COST) == 8
+    matches = app.get_fuzzy_matches('node')
+    assert matches == ['complete', 'help', 'user']
+
+
+def test_fuzzy_no_prefix():
+    # search by distance, no common prefix with any command
+    cmd_mgr = CommandManager('cliff.fuzzy')
+    app = App('test', '1.0', cmd_mgr)
+    cmd_mgr.add_command('user', utils.TestCommand)
+    matches = app.get_fuzzy_matches('uesr')
+    assert matches == ['user']