refactor(http): use headers module in file-server module (#5642)

http/file_server.ts

@@ -52,6 +52,7 @@ import { parseArgs } from "@std/cli/parse-args";
 import denoConfig from "./deno.json" with { type: "json" };
 import { format as formatBytes } from "@std/fmt/bytes";
 import { getNetworkAddress } from "@std/net/get-network-address";
+import { HEADER } from "./header.ts";
 
 interface EntryInfo {
   mode: string;
@@ -195,7 +196,7 @@ export async function serveFile(
 
   // Set date header if access timestamp is available
   if (fileInfo.atime) {
-    headers.set("date", fileInfo.atime.toUTCString());
+    headers.set(HEADER.Date, fileInfo.atime.toUTCString());
   }
 
   const etag = fileInfo.mtime
@@ -204,18 +205,18 @@ export async function serveFile(
 
   // Set last modified header if last modification timestamp is available
   if (fileInfo.mtime) {
-    headers.set("last-modified", fileInfo.mtime.toUTCString());
+    headers.set(HEADER.LastModified, fileInfo.mtime.toUTCString());
   }
   if (etag) {
-    headers.set("etag", etag);
+    headers.set(HEADER.ETag, etag);
   }
 
   if (etag || fileInfo.mtime) {
     // If a `if-none-match` header is present and the value matches the tag or
     // if a `if-modified-since` header is present and the value is bigger than
     // the access timestamp value, then return 304
-    const ifNoneMatchValue = req.headers.get("if-none-match");
-    const ifModifiedSinceValue = req.headers.get("if-modified-since");
+    const ifNoneMatchValue = req.headers.get(HEADER.IfNoneMatch);
+    const ifModifiedSinceValue = req.headers.get(HEADER.IfModifiedSince);
     if (
       (!ifNoneMatch(ifNoneMatchValue, etag)) ||
       (ifNoneMatchValue === null &&
@@ -236,12 +237,12 @@ export async function serveFile(
   // Set mime-type using the file extension in filePath
   const contentTypeValue = contentType(extname(filePath));
   if (contentTypeValue) {
-    headers.set("content-type", contentTypeValue);
+    headers.set(HEADER.ContentType, contentTypeValue);
   }
 
   const fileSize = fileInfo.size;
 
-  const rangeValue = req.headers.get("range");
+  const rangeValue = req.headers.get(HEADER.Range);
 
   // handle range request
   // Note: Some clients add a Range header to all requests to limit the size of the response.
@@ -253,7 +254,7 @@ export async function serveFile(
     // Returns 200 OK if parsing the range header fails
     if (!parsed) {
       // Set content length
-      headers.set("content-length", `${fileSize}`);
+      headers.set(HEADER.ContentLength, `${fileSize}`);
 
       const file = await Deno.open(filePath);
       const status = STATUS_CODE.OK;
@@ -271,7 +272,7 @@ export async function serveFile(
       fileSize <= parsed.start
     ) {
       // Set the "Content-range" header
-      headers.set("content-range", `bytes */${fileSize}`);
+      headers.set(HEADER.ContentRange, `bytes */${fileSize}`);
 
       return createStandardResponse(
         STATUS_CODE.RangeNotSatisfiable,
@@ -284,11 +285,11 @@ export async function serveFile(
     const end = Math.min(parsed.end, fileSize - 1);
 
     // Set the "Content-range" header
-    headers.set("content-range", `bytes ${start}-${end}/${fileSize}`);
+    headers.set(HEADER.ContentRange, `bytes ${start}-${end}/${fileSize}`);
 
     // Set content length
     const contentLength = end - start + 1;
-    headers.set("content-length", `${contentLength}`);
+    headers.set(HEADER.ContentLength, `${contentLength}`);
 
     // Return 206 Partial Content
     const file = await Deno.open(filePath);
@@ -304,7 +305,7 @@ export async function serveFile(
   }
 
   // Set content length
-  headers.set("content-length", `${fileSize}`);
+  headers.set(HEADER.ContentLength, `${fileSize}`);
 
   const file = await Deno.open(filePath);
   const status = STATUS_CODE.OK;
@@ -386,7 +387,7 @@ async function serveDirIndex(
   const page = dirViewerTemplate(formattedDirUrl, listEntry);
 
   const headers = createBaseHeaders();
-  headers.set("content-type", "text/html; charset=UTF-8");
+  headers.set(HEADER.ContentType, "text/html; charset=UTF-8");
 
   const status = STATUS_CODE.OK;
   return new Response(page, {
@@ -421,7 +422,7 @@ function createBaseHeaders(): Headers {
   return new Headers({
     server: "deno",
     // Set "accept-ranges" so that the client knows it can make range requests on future requests
-    "accept-ranges": "bytes",
+    [HEADER.AcceptRanges]: "bytes",
   });
 }
 
@@ -647,9 +648,9 @@ export async function serveDir(
   const isRedirectResponse = isRedirectStatus(response.status);
 
   if (opts.enableCors && !isRedirectResponse) {
-    response.headers.append("access-control-allow-origin", "*");
+    response.headers.append(HEADER.AccessControlAllowOrigin, "*");
     response.headers.append(
-      "access-control-allow-headers",
+      HEADER.AccessControlAllowHeaders,
       "Origin, X-Requested-With, Content-Type, Accept, Range",
     );
   }