feat(palette): add fuzzy_match with subsequence matching and scoring

tests/test_command_palette.py

@@ -0,0 +1,45 @@
+from src.command_palette import Command, ScoredCommand, fuzzy_match
+
+
+def _cmd(id: str, title: str) -> Command:
+ return Command(id=id, title=title, category="test")
+
+
+def test_fuzzy_match_prefix_ranks_first():
+ candidates = [
+  _cmd("find", "Find in Selection"),
+  _cmd("fold", "Fold All"),
+  _cmd("config", "Configure Settings"),
+ ]
+ results = fuzzy_match("fin", candidates, top_n=10)
+ assert len(results) > 0
+ assert results[0].command.id == "find"
+ assert results[0].score > 0.5
+
+
+def test_fuzzy_match_subsequence_match():
+ candidates = [_cmd("x", "Find")]
+ results = fuzzy_match("fd", candidates, top_n=10)
+ assert len(results) == 1
+ assert results[0].command.id == "x"
+
+
+def test_fuzzy_match_no_match_returns_empty():
+ candidates = [_cmd("x", "foo bar")]
+ results = fuzzy_match("xyz", candidates, top_n=10)
+ assert results == []
+
+
+def test_fuzzy_match_top_n_limits_results():
+ candidates = [_cmd(f"cmd_{i}", f"Command {i}") for i in range(50)]
+ results = fuzzy_match("cmd", candidates, top_n=10)
+ assert len(results) == 10
+
+
+def test_fuzzy_match_score_higher_for_exact_prefix():
+ candidates = [
+  _cmd("a", "find"),
+  _cmd("b", "Configure Find Settings"),
+ ]
+ results = fuzzy_match("fin", candidates, top_n=10)
+ assert results[0].command.id == "a"