From 2e98b056d92b93f3fdd3e3588c3f996e715a179d Mon Sep 17 00:00:00 2001
From: Wang Sijie <wangsijie@silverhand.io>
Date: Mon, 18 Oct 2021 18:09:48 +0800
Subject: [PATCH] feat: token-set (#48)

* feat: token-set

* refactor: nowRoundToSec
---
 packages/client/src/token-set.test.ts | 64 +++++++++++++++++++++++++++
 packages/client/src/token-set.ts      | 35 +++++++++++++++
 packages/client/src/utils.ts          |  2 +
 3 files changed, 101 insertions(+)
 create mode 100644 packages/client/src/token-set.test.ts
 create mode 100644 packages/client/src/token-set.ts

diff --git a/packages/client/src/token-set.test.ts b/packages/client/src/token-set.test.ts
new file mode 100644
index 000000000..b0a2dad7c
--- /dev/null
+++ b/packages/client/src/token-set.test.ts
@@ -0,0 +1,64 @@
+import { SignJWT } from 'jose/jwt/sign';
+import { generateKeyPair } from 'jose/util/generate_key_pair';
+
+import TokenSet from './token-set';
+import { nowRoundToSec } from './utils';
+
+describe('TokenSet', () => {
+  test('sets the expire_at automatically from expires_in', () => {
+    const ts = new TokenSet({
+      access_token: 'at',
+      expires_in: 300,
+      refresh_token: 'rt',
+      id_token: 'it',
+    });
+
+    expect(ts).toHaveProperty('expiresAt', nowRoundToSec() + 300);
+    expect(ts).toHaveProperty('expiresIn', 300);
+    expect(ts.expired()).toBeFalsy();
+  });
+
+  test('expired token sets expires_in to -30', () => {
+    const ts = new TokenSet({
+      access_token: 'at',
+      expires_in: -30,
+      refresh_token: 'rt',
+      id_token: 'it',
+    });
+
+    expect(ts).toHaveProperty('expiresAt', nowRoundToSec() - 30);
+    expect(ts).toHaveProperty('expiresIn', 0);
+    expect(ts.expired()).toBeTruthy();
+  });
+
+  test('provides a #claims getter', async () => {
+    const ts = new TokenSet({
+      access_token: 'at',
+      expires_in: -30,
+      refresh_token: 'rt',
+      id_token: await new SignJWT({})
+        .setProtectedHeader({ alg: 'RS256' })
+        .setAudience('foo')
+        .setSubject('foz')
+        .setIssuer('logto')
+        .setIssuedAt()
+        .setExpirationTime('2h')
+        .sign((await generateKeyPair('RS256')).privateKey),
+    });
+
+    expect(ts.claims().aud).toEqual('foo');
+    expect(ts.claims().sub).toEqual('foz');
+    expect(ts.claims().iss).toEqual('logto');
+  });
+
+  test('#claims throws if no id_token is present', () => {
+    const ts = new TokenSet({
+      access_token: 'at',
+      expires_in: 300,
+      refresh_token: 'rt',
+      id_token: '',
+    });
+
+    expect(() => ts.claims()).toThrowError('id_token not present in TokenSet');
+  });
+});
diff --git a/packages/client/src/token-set.ts b/packages/client/src/token-set.ts
new file mode 100644
index 000000000..d9c37e4d2
--- /dev/null
+++ b/packages/client/src/token-set.ts
@@ -0,0 +1,35 @@
+import { TokenSetParameters } from './grant-token';
+import { decodeToken, IDToken, nowRoundToSec } from './utils';
+
+export default class TokenSet {
+  public accessToken: string;
+  public idToken: string;
+  public refreshToken: string;
+  public expiresAt = 0;
+  constructor(tokenSet: TokenSetParameters) {
+    this.accessToken = tokenSet.access_token;
+    this.expiresIn = tokenSet.expires_in;
+    this.idToken = tokenSet.id_token;
+    this.refreshToken = tokenSet.refresh_token;
+  }
+
+  get expiresIn(): number {
+    return Math.max(this.expiresAt - nowRoundToSec(), 0);
+  }
+
+  set expiresIn(value: number) {
+    this.expiresAt = nowRoundToSec() + value;
+  }
+
+  public expired(): boolean {
+    return this.expiresIn === 0;
+  }
+
+  public claims(): IDToken {
+    if (!this.idToken) {
+      throw new TypeError('id_token not present in TokenSet');
+    }
+
+    return decodeToken(this.idToken);
+  }
+}
diff --git a/packages/client/src/utils.ts b/packages/client/src/utils.ts
index ec711f583..c15f0f104 100644
--- a/packages/client/src/utils.ts
+++ b/packages/client/src/utils.ts
@@ -52,3 +52,5 @@ export const decodeToken = (token: string): IDToken => {
     throw new Error('invalid token: JSON parse failed');
   }
 };
+
+export const nowRoundToSec = () => Math.floor(Date.now() / 1000);