From 85cc7f5649cd610f08bae544d5a889a463607431 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Jos=C3=A9=20Arboleda?= <soyjuanarbol@gmail.com>
Date: Fri, 18 Oct 2024 01:33:51 -0500
Subject: [PATCH] feat: add support for ETag option in res.sendFile
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This patch introduces the ability to control the ETag generation
through the `res.sendFile` function. Specifically, the ETag option
is wired to the application's configuration, allowing it to be
enabled or disabled based on the app's settings.

Fixes: https://github.com/expressjs/express/issues/2294
Signed-off-by: Juan José Arboleda <soyjuanarbol@gmail.com>
---
 History.md           |  1 +
 lib/response.js      |  3 +++
 test/res.sendFile.js | 13 +++++++++++++
 3 files changed, 17 insertions(+)

diff --git a/History.md b/History.md
index 5c7da2ad81..021315c5ab 100644
--- a/History.md
+++ b/History.md
@@ -10,6 +10,7 @@ unreleased
 * refactor: prefix built-in node module imports
 * Remove unused `depd` dependency
 * Add support for `Uint8Array` in `res.send`
+* Add support for ETag option in res.sendFile
 * deps: debug@^4.4.0
 * deps: body-parser@^2.1.0
 * deps: router@^2.1.0
diff --git a/lib/response.js b/lib/response.js
index 38f11e9237..b1dfcb2335 100644
--- a/lib/response.js
+++ b/lib/response.js
@@ -389,6 +389,9 @@ res.sendFile = function sendFile(path, options, callback) {
 
   // create file stream
   var pathname = encodeURI(path);
+
+  // wire application etag option to send
+  opts.etag = this.app.enabled('etag');
   var file = send(req, pathname, opts);
 
   // transfer
diff --git a/test/res.sendFile.js b/test/res.sendFile.js
index 505f8d114d..63ad5558b5 100644
--- a/test/res.sendFile.js
+++ b/test/res.sendFile.js
@@ -78,6 +78,19 @@ describe('res', function(){
       });
     });
 
+    it('should disable the ETag function if requested', function (done) {
+      var app = createApp(path.resolve(fixtures, 'name.txt')).disable('etag');
+
+      request(app)
+      .get('/')
+      .expect(handleHeaders)
+      .expect(200, done);
+
+      function handleHeaders (res) {
+        assert(res.headers.etag === undefined);
+      }
+    });
+
     it('should 404 for directory', function (done) {
       var app = createApp(path.resolve(fixtures, 'blog'));