fix(kiro): require fresh token before auth success

src/cliproxy/auth/oauth-handler.ts

@@ -11,7 +11,6 @@
  */
 
 import * as fs from 'fs';
-import * as path from 'path';
 import { fail, info, warn, color, ok } from '../../utils/ui';
 import { ensureCLIProxyBinary } from '../binary-manager';
 import { generateConfig } from '../config-generator';
@@ -48,9 +47,11 @@ import {
 } from './auth-types';
 import { isHeadlessEnvironment, killProcessOnPort, showStep } from './environment-detector';
 import {
+  ProviderTokenSnapshot,
+  findNewTokenSnapshotForAuthAttempt,
   getProviderTokenDir,
   isAuthenticated,
-  isTokenFileForProvider,
+  listProviderTokenSnapshots,
   registerAccountFromToken,
 } from './token-manager';
 import { executeOAuthProcess } from './oauth-process';
@@ -79,11 +80,6 @@ interface PasteCallbackStartData {
 const PASTE_CALLBACK_AUTH_URL_POLL_INTERVAL_MS = 3000;
 const POLLED_AUTH_LOCAL_TOKEN_GRACE_MS = 15 * 1000;
 
-type ProviderTokenSnapshot = {
-  file: string;
-  mtimeMs: number;
-};
-
 export async function requestPasteCallbackStart(
   provider: CLIProxyProvider,
   target: ProxyTarget,
@@ -146,56 +142,13 @@ function parseAuthUrlState(url: string | null | undefined): string | null {
   }
 }
 
-function listProviderTokenSnapshots(
-  provider: CLIProxyProvider,
-  tokenDir: string
-): ProviderTokenSnapshot[] {
-  if (!fs.existsSync(tokenDir)) {
-    return [];
-  }
-
-  return fs
-    .readdirSync(tokenDir)
-    .filter((file) => file.endsWith('.json'))
-    .map((file): ProviderTokenSnapshot | null => {
-      const filePath = path.join(tokenDir, file);
-      if (!isTokenFileForProvider(filePath, provider)) {
-        return null;
-      }
-
-      return {
-        file,
-        mtimeMs: fs.statSync(filePath).mtimeMs,
-      };
-    })
-    .filter((snapshot): snapshot is ProviderTokenSnapshot => snapshot !== null)
-    .sort((left, right) => right.mtimeMs - left.mtimeMs);
-}
-
 export function findNewTokenSnapshotForManualAuth(
   provider: CLIProxyProvider,
   tokenDir: string,
   knownTokenFiles: ProviderTokenSnapshot[],
   expectedAccountId?: string
 ): ProviderTokenSnapshot | null {
-  const knownTokenMtimes = new Map(
-    knownTokenFiles.map((snapshot) => [snapshot.file, snapshot.mtimeMs])
-  );
-
-  return (
-    listProviderTokenSnapshots(provider, tokenDir).find((snapshot) => {
-      const knownMtime = knownTokenMtimes.get(snapshot.file);
-      if (knownMtime === undefined) {
-        return true;
-      }
-
-      if (!expectedAccountId) {
-        return false;
-      }
-
-      return snapshot.mtimeMs > knownMtime + 1;
-    }) || null
-  );
+  return findNewTokenSnapshotForAuthAttempt(provider, tokenDir, knownTokenFiles, expectedAccountId);
 }
 
 async function waitForManualCallbackToken(

src/cliproxy/auth/oauth-process.ts

@@ -24,7 +24,12 @@ import {
 } from '../project-selection-handler';
 import { KiroAuthMethod, ProviderOAuthConfig } from './auth-types';
 import { getTimeoutTroubleshooting, showStep } from './environment-detector';
-import { isAuthenticated, registerAccountFromToken } from './token-manager';
+import {
+  type ProviderTokenSnapshot,
+  findNewTokenSnapshot,
+  listProviderTokenSnapshots,
+  registerAccountFromToken,
+} from './token-manager';
 import {
   deviceCodeEvents,
   DEVICE_CODE_TIMEOUT_MS,
@@ -476,20 +481,15 @@ function displayUrlFromStderr(
 
 const ANSI_ESCAPE_REGEX = /\x1b\[[0-9;]*m/g;
 
-export function extractLikelyAuthFailureFromStderr(
+export function extractLikelyAuthFailureFromLogs(
   provider: CLIProxyProvider,
-  stderrData: string
+  logData: string
 ): string | null {
-  // Keep this scoped to ghcp to avoid over-classifying other providers.
-  if (provider !== 'ghcp') {
+  if (!logData.trim()) {
     return null;
   }
 
-  if (!stderrData.trim()) {
-    return null;
-  }
-
-  const normalizedLines = stderrData
+  const normalizedLines = logData
     .split('\n')
     .map((line) => line.replace(ANSI_ESCAPE_REGEX, '').trim())
     .filter(Boolean)
@@ -507,11 +507,23 @@ export function extractLikelyAuthFailureFromStderr(
       return line;
     });
 
+  const providerPatterns: Partial<Record<CLIProxyProvider, RegExp[]>> = {
+    ghcp: [
+      /github copilot authentication failed:\s*(.+)/i,
+      /failed to verify copilot access[^:]*:\s*(.+)/i,
+    ],
+    kiro: [
+      /kiro idc authentication failed:\s*(.+)/i,
+      /kiro authentication failed:\s*(.+)/i,
+      /login failed:\s*(.+)/i,
+      /failed to register client:\s*(.+)/i,
+    ],
+  };
+
   const prioritizedPatterns = [
-    /github copilot authentication failed:\s*(.+)/i,
-    /authentication failed:\s*(.+)/i,
-    /failed to verify copilot access[^:]*:\s*(.+)/i,
-    /failed to save auth:\s*(.+)/i,
+    ...(providerPatterns[provider] || []),
+    /^authentication failed:\s*(.+)/i,
+    /^failed to save auth:\s*(.+)/i,
   ];
 
   for (let i = normalizedLines.length - 1; i >= 0; i--) {
@@ -527,6 +539,34 @@ export function extractLikelyAuthFailureFromStderr(
   return null;
 }
 
+export function extractLikelyAuthFailureFromStderr(
+  provider: CLIProxyProvider,
+  stderrData: string
+): string | null {
+  return extractLikelyAuthFailureFromLogs(provider, stderrData);
+}
+
+export function analyzeSuccessfulAuthExit(options: {
+  provider: CLIProxyProvider;
+  knownTokenFiles: ProviderTokenSnapshot[];
+  currentTokenFiles: ProviderTokenSnapshot[];
+  expectedAccountId?: string;
+  stdoutData: string;
+  stderrData: string;
+}): { tokenSnapshot: ProviderTokenSnapshot | null; failureReason: string | null } {
+  const tokenSnapshot = findNewTokenSnapshot(
+    options.currentTokenFiles,
+    options.knownTokenFiles,
+    options.expectedAccountId
+  );
+  const failureReason = extractLikelyAuthFailureFromLogs(
+    options.provider,
+    [options.stdoutData, options.stderrData].filter(Boolean).join('\n')
+  );
+
+  return { tokenSnapshot, failureReason };
+}
+
 /** Handle token not found after successful process exit */
 async function handleTokenNotFound(
   provider: CLIProxyProvider,
@@ -537,9 +577,22 @@ async function handleTokenNotFound(
   verbose: boolean,
   failureReason?: string
 ): Promise<AccountInfo | null> {
+  console.log('');
+
+  if (failureReason) {
+    // Sanitize internal URLs/paths from failure reason to avoid leaking infrastructure details
+    const sanitizedReason = failureReason
+      .replace(/https?:\/\/(?:localhost|127\.0\.0\.1|0\.0\.0\.0)[^\s]*/gi, '[internal-url]')
+      .replace(/\/(?:root|home|opt|tmp|var)\/[^\s]*/g, '[path]');
+    console.log(fail('Authentication failed before a usable token was saved'));
+    console.log(`    ${sanitizedReason}`);
+    console.log('');
+    console.log(`Try: ccs ${provider} --auth --verbose`);
+    return null;
+  }
+
   // Kiro-specific: Try auto-import from Kiro IDE
   if (provider === 'kiro') {
-    console.log('');
     console.log(warn('Callback redirected to Kiro IDE. Attempting to import token...'));
 
     const result = await tryKiroImport(tokenDir, verbose);
@@ -558,24 +611,6 @@ async function handleTokenNotFound(
     return null;
   }
 
-  // Default behavior for other providers
-  console.log('');
-
-  if (failureReason) {
-    // Sanitize internal URLs/paths from failure reason to avoid leaking infrastructure details
-    const sanitizedReason = failureReason
-      .replace(/https?:\/\/(?:localhost|127\.0\.0\.1|0\.0\.0\.0)[^\s]*/gi, '[internal-url]')
-      .replace(/\/(?:root|home|opt|tmp|var)\/[^\s]*/g, '[path]');
-    console.log(fail('Authentication completed but token was not persisted'));
-    console.log(`    ${sanitizedReason}`);
-    console.log('');
-    console.log('This usually means provider-side authorization was accepted,');
-    console.log('but CLIProxy failed a post-auth verification or token save step.');
-    console.log('');
-    console.log(`Try: ccs ${provider} --auth --verbose`);
-    return null;
-  }
-
   console.log(fail('Token not found after authentication'));
   console.log('');
   console.log('The browser showed success but callback was not received.');
@@ -644,6 +679,7 @@ export function executeOAuthProcess(options: OAuthProcessOptions): Promise<Accou
   return new Promise<AccountInfo | null>((resolve) => {
     const flowType = resolveAuthFlowType(options);
     const isDeviceCodeFlow = flowType === 'device_code';
+    const knownTokenFiles = listProviderTokenSnapshots(provider, tokenDir);
 
     // Device-code flows can usually inherit stdin, but Kiro's default AWS flow now
     // prints an intermediate Builder ID vs IDC selector that CCS auto-answers.
@@ -814,7 +850,16 @@ export function executeOAuthProcess(options: OAuthProcessOptions): Promise<Accou
       const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
 
       if (code === 0) {
-        if (isAuthenticated(provider)) {
+        const exitAnalysis = analyzeSuccessfulAuthExit({
+          provider,
+          knownTokenFiles,
+          currentTokenFiles: listProviderTokenSnapshots(provider, tokenDir),
+          expectedAccountId,
+          stdoutData: state.accumulatedOutput,
+          stderrData: state.stderrData,
+        });
+
+        if (exitAnalysis.tokenSnapshot) {
           console.log('');
           console.log(ok(`Authentication successful (${elapsed}s)`));
 
@@ -827,13 +872,11 @@ export function executeOAuthProcess(options: OAuthProcessOptions): Promise<Accou
             registerAccountFromToken(provider, tokenDir, nickname, verbose, expectedAccountId)
           );
         } else {
-          const failureReason = extractLikelyAuthFailureFromStderr(provider, state.stderrData);
-
           // Emit device code failure event for UI
           if (isDeviceCodeFlow && state.deviceCodeDisplayed) {
             deviceCodeEvents.emit('deviceCode:failed', {
               sessionId: state.sessionId,
-              error: failureReason || 'Token not found after authentication',
+              error: exitAnalysis.failureReason || 'Token not found after authentication',
             });
           }
 
@@ -845,7 +888,7 @@ export function executeOAuthProcess(options: OAuthProcessOptions): Promise<Accou
             nickname,
             expectedAccountId,
             verbose,
-            failureReason || undefined
+            exitAnalysis.failureReason || undefined
           );
           resolve(account);
         }

src/cliproxy/auth/token-manager.ts

@@ -7,6 +7,7 @@
 
 import * as fs from 'fs';
 import * as path from 'path';
+import { createHash } from 'crypto';
 import { CLIProxyProvider } from '../types';
 import { CLIPROXY_PROFILES } from '../../auth/profile-detector';
 import { getProviderAuthDir } from '../config-generator';
@@ -43,6 +44,165 @@ export function isTokenFileForProvider(filePath: string, provider: CLIProxyProvi
   }
 }
 
+export type ProviderTokenSnapshot = {
+  file: string;
+  mtimeMs: number;
+  accountId?: string;
+  fingerprint?: string;
+};
+
+type TokenCandidate = {
+  file: string;
+  filePath: string;
+  email?: string;
+  projectId?: string;
+  accountId: string;
+  mtimeMs: number;
+  alreadyRegistered: boolean;
+  fingerprint: string;
+};
+
+type RawTokenCandidate = Omit<TokenCandidate, 'accountId' | 'fingerprint'>;
+
+function buildTokenFingerprint(content: string): string {
+  return createHash('sha256').update(content).digest('hex');
+}
+
+function listTokenCandidates(provider: CLIProxyProvider, tokenDir: string): TokenCandidate[] {
+  if (!fs.existsSync(tokenDir)) {
+    return [];
+  }
+
+  const files = fs.readdirSync(tokenDir);
+  const jsonFiles = files.filter((file) => file.endsWith('.json'));
+  const existingAccounts = getProviderAccounts(provider);
+  const rawCandidates: RawTokenCandidate[] = jsonFiles.flatMap((file) => {
+    const filePath = path.join(tokenDir, file);
+    if (!isTokenFileForProvider(filePath, provider)) {
+      return [];
+    }
+
+    const content = fs.readFileSync(filePath, 'utf-8');
+    const data = JSON.parse(content) as { email?: string; project_id?: string };
+    const email = data.email || undefined;
+    const projectId = data.project_id || undefined;
+    const stats = fs.statSync(filePath);
+
+    return [
+      {
+        file,
+        filePath,
+        email,
+        projectId,
+        mtimeMs: stats.mtimeMs,
+        alreadyRegistered: existingAccounts.some((account) => account.tokenFile === file),
+      },
+    ];
+  });
+
+  const duplicateEmailCounts = new Map<string, number>();
+  const duplicateEmailTokenSets = new Map<string, Set<string>>();
+  for (const account of existingAccounts) {
+    if (!account.email) continue;
+    const key = account.email.toLowerCase();
+    const tokenSet = duplicateEmailTokenSets.get(key) ?? new Set<string>();
+    tokenSet.add(account.tokenFile);
+    duplicateEmailTokenSets.set(key, tokenSet);
+  }
+  for (const candidate of rawCandidates) {
+    if (!candidate.email) continue;
+    const key = candidate.email.toLowerCase();
+    const tokenSet = duplicateEmailTokenSets.get(key) ?? new Set<string>();
+    tokenSet.add(candidate.file);
+    duplicateEmailTokenSets.set(key, tokenSet);
+  }
+  for (const [key, tokenSet] of duplicateEmailTokenSets) {
+    duplicateEmailCounts.set(key, tokenSet.size);
+  }
+
+  return rawCandidates
+    .map((rawCandidate) => {
+      const content = fs.readFileSync(rawCandidate.filePath, 'utf-8');
+      const duplicateEmailCount = rawCandidate.email
+        ? (duplicateEmailCounts.get(rawCandidate.email.toLowerCase()) ?? 1)
+        : 1;
+      const accountId = rawCandidate.email
+        ? buildEmailBackedAccountId(
+            provider,
+            rawCandidate.file,
+            rawCandidate.email,
+            duplicateEmailCount
+          )
+        : extractAccountIdFromTokenFile(rawCandidate.file, rawCandidate.email);
+
+      return {
+        ...rawCandidate,
+        accountId,
+        fingerprint: buildTokenFingerprint(content),
+      };
+    })
+    .sort((left, right) => right.mtimeMs - left.mtimeMs);
+}
+
+export function listProviderTokenSnapshots(
+  provider: CLIProxyProvider,
+  tokenDir: string = getProviderTokenDir(provider)
+): ProviderTokenSnapshot[] {
+  return listTokenCandidates(provider, tokenDir).map((candidate) => ({
+    file: candidate.file,
+    mtimeMs: candidate.mtimeMs,
+    accountId: candidate.accountId,
+    fingerprint: candidate.fingerprint,
+  }));
+}
+
+export function findNewTokenSnapshot(
+  currentTokenFiles: ProviderTokenSnapshot[],
+  knownTokenFiles: ProviderTokenSnapshot[],
+  expectedAccountId?: string
+): ProviderTokenSnapshot | null {
+  const knownSnapshotsByFile = new Map(
+    knownTokenFiles.map((snapshot) => [snapshot.file, snapshot])
+  );
+
+  return (
+    currentTokenFiles.find((snapshot) => {
+      const knownSnapshot = knownSnapshotsByFile.get(snapshot.file);
+      if (!expectedAccountId) {
+        return !knownSnapshot;
+      }
+
+      const matchesExpectedAccount =
+        snapshot.file === expectedAccountId || snapshot.accountId === expectedAccountId;
+      if (!matchesExpectedAccount) {
+        return false;
+      }
+
+      if (!knownSnapshot) {
+        return true;
+      }
+
+      return (
+        snapshot.fingerprint !== knownSnapshot.fingerprint ||
+        snapshot.mtimeMs !== knownSnapshot.mtimeMs
+      );
+    }) || null
+  );
+}
+
+export function findNewTokenSnapshotForAuthAttempt(
+  provider: CLIProxyProvider,
+  tokenDir: string,
+  knownTokenFiles: ProviderTokenSnapshot[],
+  expectedAccountId?: string
+): ProviderTokenSnapshot | null {
+  return findNewTokenSnapshot(
+    listProviderTokenSnapshots(provider, tokenDir),
+    knownTokenFiles,
+    expectedAccountId
+  );
+}
+
 /**
  * Check if provider has valid authentication
  * CLIProxyAPI stores OAuth tokens as JSON files in the auth directory.
@@ -207,83 +367,11 @@ export function registerAccountFromToken(
   verbose = false,
   expectedAccountId?: string
 ): import('../account-manager').AccountInfo | null {
-  type TokenCandidate = {
-    file: string;
-    filePath: string;
-    email?: string;
-    projectId?: string;
-    accountId: string;
-    mtimeMs: number;
-    alreadyRegistered: boolean;
-  };
-  type RawTokenCandidate = Omit<TokenCandidate, 'accountId'>;
-
   const { registerAccount } = require('../account-manager');
   let selectedCandidate: Omit<TokenCandidate, 'mtimeMs'> | null = null;
   try {
-    const files = fs.readdirSync(tokenDir);
-    const jsonFiles = files.filter((f: string) => f.endsWith('.json'));
+    const candidates = listTokenCandidates(provider, tokenDir);
     const existingAccounts = getProviderAccounts(provider);
-    const rawCandidates: RawTokenCandidate[] = jsonFiles.flatMap((file) => {
-      const filePath = path.join(tokenDir, file);
-      if (!isTokenFileForProvider(filePath, provider)) return [];
-
-      const content = fs.readFileSync(filePath, 'utf-8');
-      const data = JSON.parse(content) as { email?: string; project_id?: string };
-      const email = data.email || undefined;
-      const projectId = data.project_id || undefined;
-      const stats = fs.statSync(filePath);
-
-      return [
-        {
-          file,
-          filePath,
-          email,
-          projectId,
-          mtimeMs: stats.mtimeMs,
-          alreadyRegistered: existingAccounts.some((account) => account.tokenFile === file),
-        },
-      ];
-    });
-    const duplicateEmailCounts = new Map<string, number>();
-    const duplicateEmailTokenSets = new Map<string, Set<string>>();
-    for (const account of existingAccounts) {
-      if (!account.email) continue;
-      const key = account.email.toLowerCase();
-      const tokenSet = duplicateEmailTokenSets.get(key) ?? new Set<string>();
-      tokenSet.add(account.tokenFile);
-      duplicateEmailTokenSets.set(key, tokenSet);
-    }
-    for (const candidate of rawCandidates) {
-      if (!candidate.email) continue;
-      const key = candidate.email.toLowerCase();
-      const tokenSet = duplicateEmailTokenSets.get(key) ?? new Set<string>();
-      tokenSet.add(candidate.file);
-      duplicateEmailTokenSets.set(key, tokenSet);
-    }
-    for (const [key, tokenSet] of duplicateEmailTokenSets) {
-      duplicateEmailCounts.set(key, tokenSet.size);
-    }
-    const candidates: TokenCandidate[] = rawCandidates
-      .map((rawCandidate) => {
-        const duplicateEmailCount = rawCandidate.email
-          ? (duplicateEmailCounts.get(rawCandidate.email.toLowerCase()) ?? 1)
-          : 1;
-        const accountId = rawCandidate.email
-          ? buildEmailBackedAccountId(
-              provider,
-              rawCandidate.file,
-              rawCandidate.email,
-              duplicateEmailCount
-            )
-          : extractAccountIdFromTokenFile(rawCandidate.file, rawCandidate.email);
-
-        return {
-          ...rawCandidate,
-          accountId,
-        };
-      })
-      .sort((a, b) => b.mtimeMs - a.mtimeMs);
 
     if (expectedAccountId) {
       selectedCandidate =

tests/unit/cliproxy/oauth-process-error-parser.test.ts

@@ -1,5 +1,7 @@
 import { describe, expect, it } from 'bun:test';
 import {
+  analyzeSuccessfulAuthExit,
+  extractLikelyAuthFailureFromLogs,
   extractLikelyAuthFailureFromStderr,
   extractLikelyOAuthAuthorizationUrl,
   getExpectedLocalCallback,
@@ -38,6 +40,123 @@ describe('oauth-process stderr parsing', () => {
     expect(parsed).not.toBeNull();
     expect((parsed as string).length).toBe(240);
   });
+
+  it('extracts kiro IDC failures from verbose stdout logs', () => {
+    const logData =
+      '[2026-04-07 11:01:21] [--------] [error] [kiro_login.go:236] Kiro IDC authentication failed: login failed: failed to register client: register client failed (status 400)';
+
+    expect(extractLikelyAuthFailureFromLogs('kiro', logData)).toBe(
+      'login failed: failed to register client: register client failed (status 400)'
+    );
+  });
+});
+
+describe('oauth-process successful exit analysis', () => {
+  it('treats unchanged existing kiro tokens as a failed add-account attempt', () => {
+    const result = analyzeSuccessfulAuthExit({
+      provider: 'kiro',
+      knownTokenFiles: [{ file: 'kiro-existing.json', mtimeMs: 100 }],
+      currentTokenFiles: [{ file: 'kiro-existing.json', mtimeMs: 100 }],
+      stdoutData:
+        '[error] Kiro IDC authentication failed: login failed: failed to register client: register client failed (status 400)',
+      stderrData: '',
+    });
+
+    expect(result.tokenSnapshot).toBeNull();
+    expect(result.failureReason).toBe(
+      'login failed: failed to register client: register client failed (status 400)'
+    );
+  });
+
+  it('treats a refreshed token file as success during reauth', () => {
+    const result = analyzeSuccessfulAuthExit({
+      provider: 'kiro',
+      knownTokenFiles: [
+        {
+          file: 'kiro-existing.json',
+          mtimeMs: 100,
+          accountId: 'kiro-existing',
+          fingerprint: 'before',
+        },
+      ],
+      currentTokenFiles: [
+        {
+          file: 'kiro-existing.json',
+          mtimeMs: 250,
+          accountId: 'kiro-existing',
+          fingerprint: 'after',
+        },
+      ],
+      expectedAccountId: 'kiro-existing.json',
+      stdoutData: '',
+      stderrData: '',
+    });
+
+    expect(result.tokenSnapshot?.file).toBe('kiro-existing.json');
+    expect(result.failureReason).toBeNull();
+  });
+
+  it('ignores unrelated new token files during reauth', () => {
+    const result = analyzeSuccessfulAuthExit({
+      provider: 'kiro',
+      knownTokenFiles: [
+        {
+          file: 'kiro-existing.json',
+          mtimeMs: 100,
+          accountId: 'kiro-existing',
+          fingerprint: 'before',
+        },
+      ],
+      currentTokenFiles: [
+        {
+          file: 'kiro-existing.json',
+          mtimeMs: 100,
+          accountId: 'kiro-existing',
+          fingerprint: 'before',
+        },
+        {
+          file: 'kiro-other.json',
+          mtimeMs: 150,
+          accountId: 'kiro-other',
+          fingerprint: 'other-after',
+        },
+      ],
+      expectedAccountId: 'kiro-existing',
+      stdoutData: '',
+      stderrData: '',
+    });
+
+    expect(result.tokenSnapshot).toBeNull();
+    expect(result.failureReason).toBeNull();
+  });
+
+  it('treats fingerprint changes as success even when mtime is unchanged', () => {
+    const result = analyzeSuccessfulAuthExit({
+      provider: 'kiro',
+      knownTokenFiles: [
+        {
+          file: 'kiro-existing.json',
+          mtimeMs: 100,
+          accountId: 'kiro-existing',
+          fingerprint: 'before',
+        },
+      ],
+      currentTokenFiles: [
+        {
+          file: 'kiro-existing.json',
+          mtimeMs: 100,
+          accountId: 'kiro-existing',
+          fingerprint: 'after',
+        },
+      ],
+      expectedAccountId: 'kiro-existing',
+      stdoutData: '',
+      stderrData: '',
+    });
+
+    expect(result.tokenSnapshot?.file).toBe('kiro-existing.json');
+    expect(result.failureReason).toBeNull();
+  });
 });
 
 describe('oauth-process manual callback validation', () => {