From 728b69d71a005ba32ebe2b6b7d79bff0a4bcfb9b Mon Sep 17 00:00:00 2001
From: Heiko Rothkranz <heiko-r@users.noreply.github.com>
Date: Fri, 3 Jun 2022 08:57:51 +0800
Subject: [PATCH] fix: Interpret `max-age=0` as a valid `cache-control` header
 (#253)

* fix: Interpret `max-age=0` as a valid `cache-control` header

* tests: added max-age=0 test

* fix: fixed linting

Co-authored-by: arthurfiorette <arthur.fiorette@gmail.com>
---
 src/header/interpreter.ts         | 2 +-
 test/header/cache-control.test.ts | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/header/interpreter.ts b/src/header/interpreter.ts
index 8b51748..34f6e96 100644
--- a/src/header/interpreter.ts
+++ b/src/header/interpreter.ts
@@ -28,7 +28,7 @@ export const defaultHeaderInterpreter: HeadersInterpreter = (headers) => {
       return 0;
     }
 
-    if (maxAge) {
+    if (maxAge !== undefined) {
       const age = headers[Header.Age];
 
       if (!age) {
diff --git a/test/header/cache-control.test.ts b/test/header/cache-control.test.ts
index d88c65e..cf0ba9f 100644
--- a/test/header/cache-control.test.ts
+++ b/test/header/cache-control.test.ts
@@ -30,4 +30,13 @@ describe('test Cache-Control header', () => {
     // 10 Seconds in milliseconds
     expect(result).toBe(10 * 1000);
   });
+
+  it('tests with max-age of 0', () => {
+    const result = defaultHeaderInterpreter({
+      [Header.CacheControl]: 'max-age=0'
+    });
+
+    expect(result).toBe(0);
+    expect(result).not.toBe('not enough headers');
+  });
 });