Class syntax

index.js

@@ -22,7 +22,8 @@ function parseCacheControl(header) {
     return cc;
 }
 
-function CachePolicy(req, res, {shared, cacheHeuristic} = {}) {
+module.exports = class CachePolicy {
+    constructor(req, res, {shared, cacheHeuristic} = {}) {
         if (!res || !res.headers) {
             throw Error("Response headers missing");
         }
@@ -49,12 +50,11 @@ function CachePolicy(req, res, {shared, cacheHeuristic} = {}) {
         if (!res.headers['cache-control'] && /no-cache/.test(res.headers.pragma)) {
             this._rescc['no-cache'] = true;
         }
-}
+    }
 
-CachePolicy.prototype = {
     now() {
         return Date.now();
-    },
+    }
 
     storable() {
         // The "no-store" request directive indicates that a cache MUST NOT store any part of either this request or any response to it.
@@ -81,14 +81,14 @@ CachePolicy.prototype = {
                 // has a status code that is defined as cacheable by default
                 statusCodeCacheableByDefault.includes(this._status)
             );
-    },
+    }
 
     _hasExplicitExpiration() {
         // 4.2.1 Calculating Freshness Lifetime
         return (this._isShared && this._rescc['s-maxage']) ||
             this._rescc['max-age'] ||
             this._resHeaders.expires;
-    },
+    }
 
     satisfiesWithoutRevalidation(req) {
         if (!req || !req.headers) {
@@ -113,12 +113,12 @@ CachePolicy.prototype = {
             // the stored response is either:
             // fresh, or allowed to be served stale
             !this.stale() // TODO: allow stale
-    },
+    }
 
     _allowsStoringAuthenticated() {
         //  following Cache-Control response directives (Section 5.2.2) have such an effect: must-revalidate, public, and s-maxage.
         return this._rescc['must-revalidate'] || this._rescc.public || this._rescc['s-maxage'];
-    },
+    }
 
     _varyMatches(req) {
         if (!this._resHeaders.vary) {
@@ -135,7 +135,7 @@ CachePolicy.prototype = {
             if (req.headers[name] !== this._reqHeaders[name]) return false;
         }
         return true;
-    },
+    }
 
     responseHeaders() {
         const headers = {};
@@ -152,7 +152,7 @@ CachePolicy.prototype = {
         }
         headers.age = `${Math.round(this.age())}`;
         return headers;
-    },
+    }
 
     /**
      * Value of the Date response header or current time if Date was demed invalid
@@ -165,7 +165,7 @@ CachePolicy.prototype = {
             return this._responseTime;
         }
         return dateValue;
-    },
+    }
 
     /**
      * Value of the Age header, in seconds, updated for the current time
@@ -182,7 +182,7 @@ CachePolicy.prototype = {
 
         const residentTime = (this.now() - this._responseTime)/1000;
         return age + residentTime;
-    },
+    }
 
     maxAge() {
         if (!this.storable() || this._rescc['no-cache']) {
@@ -231,15 +231,13 @@ CachePolicy.prototype = {
             }
         }
         return 0;
-    },
+    }
 
     timeToLive() {
         return Math.max(0, this.maxAge() - this.age())*1000;
-    },
+    }
 
     stale() {
         return this.maxAge() <= this.age();
-    },
+    }
 };
-
-module.exports = CachePolicy;