Rank slash command autocomplete matches

packages/app/src/hooks/use-agent-autocomplete.ts

@@ -11,6 +11,7 @@ import { useAutocomplete } from "./use-autocomplete";
 import { useSessionStore } from "@/stores/session-store";
 import { useHostRuntimeClient, useHostRuntimeIsConnected } from "@/runtime/host-runtime";
 import { CLIENT_SLASH_COMMANDS, type ClientSlashCommand } from "@/client-slash-commands";
+import { filterAndRankCommandAutocompleteEntries } from "@/utils/agent-command-autocomplete";
 import {
   applyFileMentionReplacement,
   findActiveFileMention,
@@ -314,7 +315,6 @@ export function useAgentAutocomplete(input: UseAgentAutocompleteInput): AgentAut
     }
 
     if (mode === "command") {
-      const filterLower = commandFilterQuery.toLowerCase();
       const providerCommands = commands.map(
         (command): AvailableCommand => ({ source: "provider", command }),
       );
@@ -326,13 +326,10 @@ export function useAgentAutocomplete(input: UseAgentAutocompleteInput): AgentAut
             ),
             ...providerCommands,
           ];
-      const matches = availableCommands.filter((entry) => {
-        if (entry.source === "provider") {
-          return entry.command.name.toLowerCase().includes(filterLower);
-        }
-        const candidates = [entry.command.name, ...entry.command.aliases];
-        return candidates.some((candidate) => candidate.toLowerCase().includes(filterLower));
-      });
+      const matches = filterAndRankCommandAutocompleteEntries(
+        availableCommands,
+        commandFilterQuery,
+      );
       const orderedMatches = orderAutocompleteOptions(matches);
       return orderedMatches.map(mapCommandToOption);
     }

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

@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+
+import { filterAndRankCommandAutocompleteEntries } from "./agent-command-autocomplete";
+
+describe("filterAndRankCommandAutocompleteEntries", () => {
+  const entries = [
+    { source: "provider" as const, command: { name: "paseo-committee" } },
+    { source: "provider" as const, command: { name: "commit" } },
+    { source: "provider" as const, command: { name: "paseo-advisor" } },
+  ];
+
+  it("ranks command-name prefixes above later word-boundary partial matches", () => {
+    const result = filterAndRankCommandAutocompleteEntries(entries, "comm");
+
+    expect(result.map((entry) => entry.command.name)).toEqual(["commit", "paseo-committee"]);
+  });
+
+  it("matches client command aliases", () => {
+    const result = filterAndRankCommandAutocompleteEntries(
+      [
+        { source: "client" as const, command: { name: "exit", aliases: ["quit", "q"] } },
+        { source: "client" as const, command: { name: "clear", aliases: ["new"] } },
+      ],
+      "q",
+    );
+
+    expect(result.map((entry) => entry.command.name)).toEqual(["exit"]);
+  });
+});

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);
+}