Fix 'setExpiration' to return seconds

README.md

@@ -79,13 +79,13 @@ If the JWT is invalid, the promise resolves to
 #### setExpiration(exp: number | Date): number
 
 Additionally there is the helper function `setExpiration` which simplifies
-setting an expiration date.
+setting an expiration date. It takes either an `Date` object or a number (in seconds) as argument.
 
 ```javascript
 // A specific date:
-setExpiration(new Date("2022-07-01"))
+setExpiration(new Date("2025-07-01"))
 // One hour from now:
-setExpiration(new Date().getTime() + 60 * 60 * 1000)
+setExpiration(60 * 60)
 ```
 
 ## Example
@@ -104,7 +104,7 @@ import { makeJwt, setExpiration, Jose, Payload } from "https://deno.land/x/djwt/
 const key = "your-secret";
 const payload: Payload = {
   iss: "joe",
-  exp: setExpiration(new Date().getTime() + 60000),
+  exp: setExpiration(60),
 };
 const header: Jose = {
   alg: "HS256",

create.ts

@@ -36,7 +36,7 @@ interface Jose {
 // returns the number of seconds since January 1, 1970, 00:00:00 UTC
 function setExpiration(exp: number | Date): number {
   return Math.round(
-    (exp instanceof Date ? exp : new Date(exp)).getTime() / 1000
+    (exp instanceof Date ? exp.getTime() : Date.now() + exp * 1000) / 1000
   );
 }
 

examples/example.ts

@@ -4,7 +4,7 @@ import { validateJwt } from "../validate.ts";
 const payload = {
   iss: "joe",
   jti: "123456789abc",
-  exp: setExpiration(new Date().getTime() + 20000),
+  exp: setExpiration(new Date("July 26, 2040 22:43:00")),
 };
 const header = {
   alg: "HS256" as const,

examples/readme_example.ts

@@ -5,7 +5,7 @@ import { makeJwt, setExpiration, Jose, Payload } from "../create.ts";
 const key = "your-secret";
 const payload: Payload = {
   iss: "joe",
-  exp: setExpiration(new Date().getTime() + 60000),
+  exp: setExpiration(60),
 };
 const header: Jose = {
   alg: "HS256",

tests/djwt_test.ts

@@ -35,19 +35,22 @@ Deno.test("makeSetAndCheckExpirationTest", function (): void {
   // A specific date:
   const t1 = setExpiration(new Date("2020-01-01"));
   const t2 = setExpiration(new Date("2099-01-01"));
+  // Ten seconds from now:
+  const t3 = setExpiration(10);
   // One hour from now:
-  const t3 = setExpiration(new Date().getTime() + 60 * 60 * 1000);
+  const t4 = setExpiration(60 * 60);
   //  1 second from now:
-  const t4 = setExpiration(new Date().getTime() + 1000);
+  const t5 = setExpiration(1);
   //  1 second earlier:
-  const t5 = setExpiration(new Date().getTime() - 1000);
+  const t6 = setExpiration(-1);
   assertEquals(isExpired(t1), true);
   assertEquals(isExpired(t2), false);
-  assertEquals(isExpired(t3), false);
+  assertEquals(10, t3 - Math.round(Date.now() / 1000));
   assertEquals(isExpired(t4), false);
-  assertEquals(isExpired(t5), true);
+  assertEquals(isExpired(t5), false);
+  assertEquals(isExpired(t6), true);
   // add leeway:
-  assertEquals(isExpired(t5, 1500), false);
+  assertEquals(isExpired(t6, 1500), false);
 });
 
 Deno.test("makeDataConversionTest", function (): void {
@@ -206,7 +209,7 @@ Deno.test("testExpiredJwt", async function (): Promise<void> {
   const payload = {
     iss: "joe",
     jti: "123456789abc",
-    exp: setExpiration(new Date().getTime() - 20000),
+    exp: setExpiration(-20000),
   };
   const header = {
     alg: "HS256" as const,
@@ -226,7 +229,7 @@ Deno.test("makeCheckHeaderCritTest", async function (): Promise<void> {
   const payload = {
     iss: "joe",
     jti: "123456789abc",
-    exp: setExpiration(new Date().getTime() + 1),
+    exp: setExpiration(1),
   };
   const header = {
     alg: "HS256" as const,
@@ -250,7 +253,7 @@ Deno.test("makeHeaderCritTest", async function (): Promise<void> {
   const payload = {
     iss: "joe",
     jti: "123456789abc",
-    exp: setExpiration(new Date().getTime() + 1),
+    exp: setExpiration(1),
   };
   const header = {
     alg: "HS256" as const,