Rank slash command autocomplete matches

packages/app/src/utils/agent-command-autocomplete.ts

@@ -0,0 +1,48 @@
+import { compareMatchScores, type MatchScore, scoreTextFields } from "@/utils/score-match";
+
+interface CommandAutocompleteEntry {
+  command: {
+    name: string;
+    aliases?: readonly string[];
+  };
+}
+
+interface ScoredCommandAutocompleteEntry<TEntry> {
+  entry: TEntry;
+  score: MatchScore;
+}
+
+function scoreCommandAutocompleteEntry(
+  entry: CommandAutocompleteEntry,
+  query: string,
+): MatchScore | null {
+  return scoreTextFields(query, [entry.command.name, ...(entry.command.aliases ?? [])]);
+}
+
+export function filterAndRankCommandAutocompleteEntries<TEntry extends CommandAutocompleteEntry>(
+  entries: readonly TEntry[],
+  query: string,
+): TEntry[] {
+  const normalizedQuery = query.trim().toLowerCase();
+  if (normalizedQuery.length === 0) {
+    return [...entries];
+  }
+
+  const scoredEntries: ScoredCommandAutocompleteEntry<TEntry>[] = [];
+  for (const entry of entries) {
+    const score = scoreCommandAutocompleteEntry(entry, normalizedQuery);
+    if (score) {
+      scoredEntries.push({ entry, score });
+    }
+  }
+
+  scoredEntries.sort((a, b) => {
+    const scoreComparison = compareMatchScores(a.score, b.score);
+    if (scoreComparison !== 0) {
+      return scoreComparison;
+    }
+    return a.entry.command.name.localeCompare(b.entry.command.name);
+  });
+
+  return scoredEntries.map((scored) => scored.entry);
+}