Show actionable error when Slack locks cookie database

[devxoul]

Summary

When the Slack desktop app is running, it holds an EBUSY lock on the Cookies SQLite file. copyFileSync fails silently, returning an empty cookie — leading to confusing "No workspace configured" or "Extracted tokens are invalid" errors with no hint about the actual cause. Now the EBUSY error is detected and surfaces a clear message telling the user to quit Slack and retry.

Changes

token-extractor.ts

• Catch EBUSY from copyFileSync in readCookieFromDB() and throw with a descriptive message instead of silently returning ''.

ensure-auth.ts

• Propagate cookie-lock errors instead of swallowing them in the catch-all. Other extraction errors (e.g. Slack not installed) are still silently ignored.

Before

$ agent-slack auth status
{"error":"No workspace configured. Run \"auth extract\" first."}

After

$ agent-slack auth status
{"error":"Failed to read Slack cookies. The Slack app is currently running and locking the cookie database. Quit the Slack app completely and try again."}

Verification

• bun typecheck — clean.
• bun test — 852 pass, 0 fail.

---

Summary by cubic

Shows a clear, actionable error when the Slack app locks the cookies database (EBUSY), telling users to quit Slack and try again. Prevents silent failures that caused “No workspace configured” or “invalid token” messages.

• Bug Fixes
  • Detects EBUSY during cookie DB copy and throws a helpful message.
  • ensureSlackAuth only extracts when no workspace is set and propagates cookie-lock errors; other extraction errors remain ignored.

^{Written for commit f0f51e3. Summary will update on new commits.}

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1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
agent-messenger	Ignored		Mar 5, 2026 5:47am

[cubic-dev-ai]

2 issues found across 4 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="src/platforms/slack/token-extractor.test.ts">

<violation number="1" location="src/platforms/slack/token-extractor.test.ts:156">
P2: Restore the `copyFileSync` spy in a `finally` block to avoid leaking a global fs mock when the assertion fails.</violation>
</file>

<file name="src/platforms/slack/ensure-auth.ts">

<violation number="1" location="src/platforms/slack/ensure-auth.ts:30">
P2: The new cookie-lock check can throw inside the catch block when `error` is not an `Error` object, which can mask the original exception.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P2: Restore the copyFileSync spy in a finally block to avoid leaking a global fs mock when the assertion fails.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At src/platforms/slack/token-extractor.test.ts, line 156:

<comment>Restore the `copyFileSync` spy in a `finally` block to avoid leaking a global fs mock when the assertion fails.</comment>

<file context>
@@ -133,6 +134,31 @@ describe('TokenExtractor Windows DPAPI', () => {
+    })
+
+    // when — then
+    const extractor = new TokenExtractor('darwin', slackDir)
+    await expect(extractor.extract()).rejects.toThrow('Quit the Slack app completely and try again')
+
</file context>

Suggested change

	const extractor = new TokenExtractor('darwin', slackDir)
	await expect(extractor.extract()).rejects.toThrow('Quit the Slack app completely and try again')
	copyFileSyncSpy.mockRestore()
	try {
	const extractor = new TokenExtractor('darwin', slackDir)
	await expect(extractor.extract()).rejects.toThrow('Quit the Slack app completely and try again')
	} finally {
	copyFileSyncSpy.mockRestore()
	}

[cubic-dev-ai]

P2: The new cookie-lock check can throw inside the catch block when error is not an Error object, which can mask the original exception.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At src/platforms/slack/ensure-auth.ts, line 30:

<comment>The new cookie-lock check can throw inside the catch block when `error` is not an `Error` object, which can mask the original exception.</comment>

<file context>
@@ -26,5 +26,10 @@ export async function ensureSlackAuth(): Promise<void> {
     }
-  } catch {}
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code === 'EBUSY' || (error as Error).message.includes('locking the cookie')) {
+      throw error
+    }
</file context>

Suggested change

	if ((error as NodeJS.ErrnoException).code === 'EBUSY' || (error as Error).message.includes('locking the cookie')) {
	const code = typeof error === 'object' && error !== null ? (error as NodeJS.ErrnoException).code : undefined
	const message = error instanceof Error ? error.message : String(error)
	if (code === 'EBUSY' || message.includes('locking the cookie')) {