refactor(channels): share channel config matching

Co-authored-by: Codex <codex@openai.com>

src/channels/channel-config.ts

@@ -0,0 +1,41 @@
+export type ChannelEntryMatch<T> = {
+  entry?: T;
+  key?: string;
+  wildcardEntry?: T;
+  wildcardKey?: string;
+};
+
+export function buildChannelKeyCandidates(
+  ...keys: Array<string | undefined | null>
+): string[] {
+  const seen = new Set<string>();
+  const candidates: string[] = [];
+  for (const key of keys) {
+    if (typeof key !== "string") continue;
+    const trimmed = key.trim();
+    if (!trimmed || seen.has(trimmed)) continue;
+    seen.add(trimmed);
+    candidates.push(trimmed);
+  }
+  return candidates;
+}
+
+export function resolveChannelEntryMatch<T>(params: {
+  entries?: Record<string, T>;
+  keys: string[];
+  wildcardKey?: string;
+}): ChannelEntryMatch<T> {
+  const entries = params.entries ?? {};
+  const match: ChannelEntryMatch<T> = {};
+  for (const key of params.keys) {
+    if (!Object.prototype.hasOwnProperty.call(entries, key)) continue;
+    match.entry = entries[key];
+    match.key = key;
+    break;
+  }
+  if (params.wildcardKey && Object.prototype.hasOwnProperty.call(entries, params.wildcardKey)) {
+    match.wildcardEntry = entries[params.wildcardKey];
+    match.wildcardKey = params.wildcardKey;
+  }
+  return match;
+}

src/discord/monitor.test.ts

@@ -9,6 +9,7 @@ import {
   normalizeDiscordSlug,
   registerDiscordListener,
   resolveDiscordChannelConfig,
+  resolveDiscordChannelConfigWithFallback,
   resolveDiscordGuildEntry,
   resolveDiscordReplyTarget,
   resolveDiscordShouldRequireMention,
@@ -160,6 +161,46 @@ describe("discord guild/channel resolution", () => {
     });
     expect(channel?.allowed).toBe(false);
   });
+
+  it("inherits parent config for thread channels", () => {
+    const guildInfo: DiscordGuildEntryResolved = {
+      channels: {
+        general: { allow: true },
+        random: { allow: false },
+      },
+    };
+    const thread = resolveDiscordChannelConfigWithFallback({
+      guildInfo,
+      channelId: "thread-123",
+      channelName: "topic",
+      channelSlug: "topic",
+      parentId: "999",
+      parentName: "random",
+      parentSlug: "random",
+      scope: "thread",
+    });
+    expect(thread?.allowed).toBe(false);
+  });
+
+  it("does not match thread name/slug when resolving allowlists", () => {
+    const guildInfo: DiscordGuildEntryResolved = {
+      channels: {
+        general: { allow: true },
+        random: { allow: false },
+      },
+    };
+    const thread = resolveDiscordChannelConfigWithFallback({
+      guildInfo,
+      channelId: "thread-999",
+      channelName: "general",
+      channelSlug: "general",
+      parentId: "999",
+      parentName: "random",
+      parentSlug: "random",
+      scope: "thread",
+    });
+    expect(thread?.allowed).toBe(false);
+  });
 });
 
 describe("discord mention gating", () => {

src/discord/monitor.ts

@@ -9,6 +9,7 @@ export {
   normalizeDiscordAllowList,
   normalizeDiscordSlug,
   resolveDiscordChannelConfig,
+  resolveDiscordChannelConfigWithFallback,
   resolveDiscordCommandAuthorized,
   resolveDiscordGuildEntry,
   resolveDiscordShouldRequireMention,

src/discord/monitor/allow-list.ts

@@ -1,5 +1,6 @@
 import type { Guild, User } from "@buape/carbon";
 
+import { buildChannelKeyCandidates, resolveChannelEntryMatch } from "../../channels/channel-config.js";
 import { formatDiscordUserTag } from "./format.js";
 
 export type DiscordAllowList = {
@@ -138,17 +139,25 @@ export function resolveDiscordGuildEntry(params: {
 }
 
 type DiscordChannelEntry = NonNullable<DiscordGuildEntryResolved["channels"]>[string];
+type DiscordChannelLookup = {
+  id: string;
+  name?: string;
+  slug?: string;
+};
+type DiscordChannelScope = "channel" | "thread";
 
 function resolveDiscordChannelEntry(
   channels: NonNullable<DiscordGuildEntryResolved["channels"]>,
-  channelId: string,
-  channelName?: string,
-  channelSlug?: string,
+  params: DiscordChannelLookup & { allowNameMatch?: boolean },
 ): DiscordChannelEntry | null {
-  if (channelId && channels[channelId]) return channels[channelId];
-  if (channelSlug && channels[channelSlug]) return channels[channelSlug];
-  if (channelName && channels[channelName]) return channels[channelName];
-  return null;
+  const allowNameMatch = params.allowNameMatch !== false;
+  const keys = buildChannelKeyCandidates(
+    params.id,
+    allowNameMatch ? params.slug : undefined,
+    allowNameMatch ? params.name : undefined,
+  );
+  const { entry } = resolveChannelEntryMatch({ entries: channels, keys });
+  return entry ?? null;
 }
 
 function resolveDiscordChannelConfigEntry(
@@ -174,7 +183,11 @@ export function resolveDiscordChannelConfig(params: {
   const { guildInfo, channelId, channelName, channelSlug } = params;
   const channels = guildInfo?.channels;
   if (!channels) return null;
-  const entry = resolveDiscordChannelEntry(channels, channelId, channelName, channelSlug);
+  const entry = resolveDiscordChannelEntry(channels, {
+    id: channelId,
+    name: channelName,
+    slug: channelSlug,
+  });
   if (!entry) return { allowed: false };
   return resolveDiscordChannelConfigEntry(entry);
 }
@@ -187,21 +200,34 @@ export function resolveDiscordChannelConfigWithFallback(params: {
   parentId?: string;
   parentName?: string;
   parentSlug?: string;
+  scope?: DiscordChannelScope;
 }): DiscordChannelConfigResolved | null {
-  const { guildInfo, channelId, channelName, channelSlug, parentId, parentName, parentSlug } =
-    params;
+  const {
+    guildInfo,
+    channelId,
+    channelName,
+    channelSlug,
+    parentId,
+    parentName,
+    parentSlug,
+    scope,
+  } = params;
   const channels = guildInfo?.channels;
   if (!channels) return null;
-  const entry = resolveDiscordChannelEntry(channels, channelId, channelName, channelSlug);
+  const entry = resolveDiscordChannelEntry(channels, {
+    id: channelId,
+    name: channelName,
+    slug: channelSlug,
+    allowNameMatch: scope !== "thread",
+  });
   if (entry) return resolveDiscordChannelConfigEntry(entry);
   if (parentId || parentName || parentSlug) {
     const resolvedParentSlug = parentSlug ?? (parentName ? normalizeDiscordSlug(parentName) : "");
-    const parentEntry = resolveDiscordChannelEntry(
-      channels,
-      parentId ?? "",
-      parentName,
-      resolvedParentSlug,
-    );
+    const parentEntry = resolveDiscordChannelEntry(channels, {
+      id: parentId ?? "",
+      name: parentName,
+      slug: resolvedParentSlug,
+    });
     if (parentEntry) return resolveDiscordChannelConfigEntry(parentEntry);
   }
   return { allowed: false };

src/discord/monitor/message-handler.preflight.ts

@@ -249,6 +249,7 @@ export async function preflightDiscordMessage(
         parentId: threadParentId ?? undefined,
         parentName: threadParentName ?? undefined,
         parentSlug: threadParentSlug,
+        scope: threadChannel ? "thread" : "channel",
       })
     : null;
   if (isGuildMessage && channelConfig?.enabled === false) {

src/discord/monitor/native-command.ts

@@ -553,6 +553,7 @@ async function dispatchDiscordCommandInteraction(params: {
         parentId: threadParentId,
         parentName: threadParentName,
         parentSlug: threadParentSlug,
+        scope: isThreadChannel ? "thread" : "channel",
       })
     : null;
   if (channelConfig?.enabled === false) {

src/slack/monitor/channel-config.ts

@@ -1,5 +1,6 @@
 import type { SlackReactionNotificationMode } from "../../config/config.js";
 import type { SlackMessageEvent } from "../types.js";
+import { buildChannelKeyCandidates, resolveChannelEntryMatch } from "../../channels/channel-config.js";
 import { allowListMatches, normalizeAllowListLower, normalizeSlackSlug } from "./allow-list.js";
 
 export type SlackChannelConfigResolved = {
@@ -77,31 +78,17 @@ export function resolveSlackChannelConfig(params: {
   const keys = Object.keys(entries);
   const normalizedName = channelName ? normalizeSlackSlug(channelName) : "";
   const directName = channelName ? channelName.trim() : "";
-  const candidates = [
+  const candidates = buildChannelKeyCandidates(
     channelId,
-    channelName ? `#${directName}` : "",
+    channelName ? `#${directName}` : undefined,
     directName,
     normalizedName,
-  ].filter(Boolean);
-
-  let matched:
-    | {
-        enabled?: boolean;
-        allow?: boolean;
-        requireMention?: boolean;
-        allowBots?: boolean;
-        users?: Array<string | number>;
-        skills?: string[];
-        systemPrompt?: string;
-      }
-    | undefined;
-  for (const candidate of candidates) {
-    if (candidate && entries[candidate]) {
-      matched = entries[candidate];
-      break;
-    }
-  }
-  const fallback = entries["*"];
+  );
+  const { entry: matched, wildcardEntry: fallback } = resolveChannelEntryMatch({
+    entries,
+    keys: candidates,
+    wildcardKey: "*",
+  });
 
   const requireMentionDefault = defaultRequireMention ?? true;
   if (keys.length === 0) {