fix(slack): land #26878 allowlist channel ID case-insensitive match (thanks @lbo728)

Land contributor PR #26878 from @lbo728; include changelog credit and regression tests.

Co-authored-by: lbo728 <extreme0728@gmail.com>

src/slack/monitor/channel-config.ts

@@ -96,8 +96,16 @@ export function resolveSlackChannelConfig(params: {
   const keys = Object.keys(entries);
   const normalizedName = channelName ? normalizeSlackSlug(channelName) : "";
   const directName = channelName ? channelName.trim() : "";
+  // Slack always delivers channel IDs in uppercase (e.g. C0ABC12345) but
+  // operators commonly write them in lowercase in their config. Add both
+  // case variants so the lookup is case-insensitive without requiring a full
+  // entry-scan. buildChannelKeyCandidates deduplicates identical keys.
+  const channelIdLower = channelId.toLowerCase();
+  const channelIdUpper = channelId.toUpperCase();
   const candidates = buildChannelKeyCandidates(
     channelId,
+    channelIdLower !== channelId ? channelIdLower : undefined,
+    channelIdUpper !== channelId ? channelIdUpper : undefined,
     channelName ? `#${directName}` : undefined,
     directName,
     normalizedName,

src/slack/monitor/monitor.test.ts

@@ -60,6 +60,27 @@ describe("resolveSlackChannelConfig", () => {
       matchSource: "direct",
     });
   });
+
+  it("matches channel config key stored in lowercase when Slack delivers uppercase channel ID", () => {
+    // Slack always delivers channel IDs in uppercase (e.g. C0ABC12345).
+    // Users commonly copy them in lowercase from docs or older CLI output.
+    const res = resolveSlackChannelConfig({
+      channelId: "C0ABC12345",
+      channels: { c0abc12345: { allow: true, requireMention: false } },
+      defaultRequireMention: true,
+    });
+    expect(res).toMatchObject({ allowed: true, requireMention: false });
+  });
+
+  it("matches channel config key stored in uppercase when user types lowercase channel ID", () => {
+    // Defensive: also handle the inverse direction.
+    const res = resolveSlackChannelConfig({
+      channelId: "c0abc12345",
+      channels: { C0ABC12345: { allow: true, requireMention: false } },
+      defaultRequireMention: true,
+    });
+    expect(res).toMatchObject({ allowed: true, requireMention: false });
+  });
 });
 
 const baseParams = () => ({