add tests

Signed-off-by: flakey5 <[email protected]>

Author: flakey5

lib/interceptor/cache.js

@@ -61,8 +61,12 @@ function needsRevalidation (now, value, age, cacheControlDirectives) {
 
   if (cacheControlDirectives?.['min-fresh']) {
     // https://www.rfc-editor.org/rfc/rfc9111.html#section-5.2.1.3
-    const gracePeriod = age + (cacheControlDirectives['min-fresh'] * 1000)
-    return (now - value.staleAt) > gracePeriod
+
+    // At this point, staleAt is always > now
+    const timeLeftTillStale = value.staleAt - now
+    const threshold = cacheControlDirectives['min-fresh'] * 1000
+
+    return timeLeftTillStale <= threshold
   }
 
   return false
@@ -119,16 +123,19 @@ module.exports = (opts = {}) => {
         return dispatch(opts, new CacheHandler(globalOpts, opts, handler))
       }
 
-      let onErrorCalled = false
+      const now = Date.now()
 
       /**
        * @param {import('../../types/cache-interceptor.d.ts').default.CacheStoreReadable} stream
        * @param {import('../../types/cache-interceptor.d.ts').default.CacheStoreValue} value
+       * @param {number} age
        */
-      const respondWithCachedValue = (stream, value) => {
+      const respondWithCachedValue = (stream, value, age) => {
         const ac = new AbortController()
         const signal = ac.signal
 
+        let onErrorCalled = false
+
         signal.onabort = (_, err) => {
           stream.destroy()
           if (!onErrorCalled) {
@@ -153,8 +160,6 @@ module.exports = (opts = {}) => {
           if (typeof handler.onHeaders === 'function') {
             // Add the age header
             // https://www.rfc-editor.org/rfc/rfc9111.html#name-age
-            const age = Math.round((Date.now() - value.cachedAt) / 1000)
-
             value.rawHeaders.push(AGE_HEADER, Buffer.from(`${age}`))
 
             handler.onHeaders(value.statusCode, value.rawHeaders, stream.resume, value.statusMessage)
@@ -209,7 +214,6 @@ module.exports = (opts = {}) => {
 
         const { value } = stream
 
-        const now = Date.now()
         const age = Math.round((now - value.cachedAt) / 1000)
         if (requestCacheControl?.['max-age'] && age >= requestCacheControl['max-age']) {
           // Response is considered expired for this specific request
@@ -250,7 +254,7 @@ module.exports = (opts = {}) => {
           return
         }
 
-        respondWithCachedValue(stream, value)
+        respondWithCachedValue(stream, value, age)
       }
 
       Promise.resolve(stream).then(handleStream).catch(handler.onError)