Add weak validator for Etag header

Author: ije

server/mod.ts

@@ -141,11 +141,11 @@ export const serve = (options: ServerOptions = {}) => {
           const deployId = getDeploymentId();
           let etag: string | null = null;
           if (deployId) {
-            etag = `${btoa(pathname).replace(/[^a-z0-9]/g, "")}-${deployId}`;
+            etag = `W/${btoa(pathname).replace(/[^a-z0-9]/g, "")}-${deployId}`;
           } else {
             const { mtime, size } = stat;
             if (mtime) {
-              etag = mtime.getTime().toString(16) + "-" + size.toString(16);
+              etag = `W/${mtime.getTime().toString(16)}-${size.toString(16)}`;
               headers.append("Last-Modified", new Date(mtime).toUTCString());
             }
           }

server/renderer.ts

@@ -168,11 +168,11 @@ export default {
       const deployId = getDeploymentId();
       let etag: string | null = null;
       if (deployId) {
-        etag = `${btoa("./index.html").replace(/[^a-z0-9]/g, "")}-${deployId}`;
+        etag = `W/${btoa("./index.html").replace(/[^a-z0-9]/g, "")}-${deployId}`;
       } else {
         const { mtime, size } = await Deno.lstat("./index.html");
         if (mtime) {
-          etag = mtime.getTime().toString(16) + "-" + size.toString(16);
+          etag = `W/${mtime.getTime().toString(16)}-${size.toString(16)}`;
           headers.append("Last-Modified", new Date(mtime).toUTCString());
         }
       }

server/serve_dist.ts

@@ -29,15 +29,15 @@ export default {
       const deployId = getDeploymentId();
       let etag: string | null = null;
       if (deployId) {
-        etag = `${btoa(pathname).replace(/[^a-z0-9]/g, "")}-${deployId}`;
+        etag = `W/${btoa(pathname).replace(/[^a-z0-9]/g, "")}-${deployId}`;
       } else {
         const stat = await Deno.lstat(filePath);
         if (!stat.isFile) {
           return new Response("File Not Found", { status: 404 });
         }
         const { mtime, size } = stat;
         if (mtime) {
-          etag = mtime.getTime().toString(16) + "-" + size.toString(16);
+          etag = `W/${mtime.getTime().toString(16)}-${size.toString(16)}`;
           headers.append("Last-Modified", new Date(mtime).toUTCString());
         }
       }

server/transformer.ts

@@ -57,7 +57,7 @@ export default {
     }
 
     const etag = mtime
-      ? `${mtime.toString(16)}-${sourceCode.length.toString(16)}-${buildHash.slice(0, 8)}`
+      ? `W/${mtime.toString(16)}-${sourceCode.length.toString(16)}-${buildHash.slice(0, 8)}`
       : await util.computeHash("sha-1", sourceCode + buildHash);
     if (req.headers.get("If-None-Match") === etag) {
       return new Response(null, { status: 304 });