fix(auth): atomically exchange gateway tokens

app/game-api/test/accessTokenStore.test.ts

@@ -1,5 +1,7 @@
 import { describe, expect, it, vi } from 'vitest';
 
+import type { GameSessionTokenPayload } from '@sammo-ts/common/auth/gameToken';
+
 import { RedisAccessTokenStore } from '../src/auth/accessTokenStore.js';
 
 describe('RedisAccessTokenStore.revoke', () => {
@@ -33,3 +35,69 @@ describe('RedisAccessTokenStore.revoke', () => {
         expect(del).not.toHaveBeenCalled();
     });
 });
+
+describe('RedisAccessTokenStore.issueFromGateway', () => {
+    const payload = {
+        sessionId: 'gateway-session-1',
+        profile: 'che:default',
+        issuedAt: '2099-01-01T00:00:00.000Z',
+        expiresAt: '2099-01-01T01:00:00.000Z',
+        user: { id: 'user-1', username: 'tester' },
+        roles: [],
+        sanctions: [],
+    } as unknown as GameSessionTokenPayload;
+
+    it('issues the access key and consumes the gateway token in one Redis evaluation', async () => {
+        const evalCommand = vi.fn(async (_script: string, _options: { keys: string[]; arguments: string[] }) => 1);
+        const store = new RedisAccessTokenStore(
+            {
+                get: async () => null,
+                set: async () => null,
+                eval: evalCommand,
+            },
+            'che:default'
+        );
+
+        const issued = await store.issueFromGateway(payload);
+
+        expect(issued).toMatchObject({ expiresAt: payload.expiresAt });
+        expect(issued && issued !== 'ALREADY_USED' ? issued.accessToken : '').toMatch(/^ga_/);
+        expect(evalCommand).toHaveBeenCalledTimes(1);
+        expect(evalCommand.mock.calls[0]?.[1].keys[0]).toBe('sammo:game:gateway-used:che:default:gateway-session-1');
+        expect(evalCommand.mock.calls[0]?.[1].keys[1]).toBe(
+            `sammo:game:access:che:default:${issued && issued !== 'ALREADY_USED' ? issued.accessToken : ''}`
+        );
+    });
+
+    it('can retry after an atomic Redis evaluation fails before commit', async () => {
+        const keys = new Set<string>();
+        let attempts = 0;
+        const evalCommand = vi.fn(async (_script: string, options: { keys: string[] }) => {
+            attempts += 1;
+            if (attempts === 1) {
+                throw new Error('injected Redis failure');
+            }
+            if (keys.has(options.keys[0] ?? '')) {
+                return 0;
+            }
+            keys.add(options.keys[0] ?? '');
+            keys.add(options.keys[1] ?? '');
+            return 1;
+        });
+        const store = new RedisAccessTokenStore(
+            {
+                get: async () => null,
+                set: async () => null,
+                eval: evalCommand,
+            },
+            'che:default'
+        );
+
+        await expect(store.issueFromGateway(payload)).rejects.toThrow('injected Redis failure');
+        expect(keys.size).toBe(0);
+        await expect(store.issueFromGateway(payload)).resolves.toMatchObject({ expiresAt: payload.expiresAt });
+        expect([...keys].filter((key) => key.includes(':access:'))).toHaveLength(1);
+        expect([...keys].filter((key) => key.includes(':gateway-used:'))).toHaveLength(1);
+        await expect(store.issueFromGateway(payload)).resolves.toBe('ALREADY_USED');
+    });
+});

app/game-api/test/router.test.ts

@@ -309,8 +309,7 @@ describe('appRouter', () => {
             throw new Error('ordinary exchange must not read the icon source');
         });
         const accessTokenStore = {
-            markGatewayTokenUsed: vi.fn(async () => true),
-            create: vi.fn(async () => ({
+            issueFromGateway: vi.fn(async () => ({
                 accessToken: 'ga_access',
                 expiresAt: '2099-01-01T01:00:00.000Z',
             })),
@@ -342,14 +341,13 @@ describe('appRouter', () => {
         const calls: string[] = [];
         const revision = '2099-01-01T00:00:00.001Z';
         const accessTokenStore = {
-            markGatewayTokenUsed: vi.fn(async () => {
+            issueFromGateway: vi.fn(async () => {
                 calls.push('mark-used');
-                return true;
+                return {
+                    accessToken: 'ga_access',
+                    expiresAt: '2099-01-01T01:00:00.000Z',
+                };
             }),
-            create: vi.fn(async () => ({
-                accessToken: 'ga_access',
-                expiresAt: '2099-01-01T01:00:00.000Z',
-            })),
         } as unknown as RedisAccessTokenStore;
         const payload = buildAuth();
         payload.issuedAt = '2099-01-01T00:00:00.000Z';