From 60869c2598321386f57e55537e8c99ed011fbb95 Mon Sep 17 00:00:00 2001
From: Mark Ladyshau <47859603+mrkldshv@users.noreply.github.com>
Date: Sun, 19 Jun 2022 23:33:24 +0200
Subject: [PATCH] fix(ext/fetch): add `accept-language` default header to fetch
 (#14882)

---
 cli/tests/unit/fetch_test.ts | 36 ++++++++++++++++++++++++++++++++++++
 ext/fetch/26_fetch.js        |  4 ++++
 tools/wpt/expectation.json   | 10 +++-------
 3 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/cli/tests/unit/fetch_test.ts b/cli/tests/unit/fetch_test.ts
index 0720a05318..7adbb77216 100644
--- a/cli/tests/unit/fetch_test.ts
+++ b/cli/tests/unit/fetch_test.ts
@@ -643,6 +643,39 @@ Deno.test(
       "hello: World\r\n",
       "foo: Bar\r\n",
       "accept: */*\r\n",
+      "accept-language: *\r\n",
+      `user-agent: Deno/${Deno.version.deno}\r\n`,
+      "accept-encoding: gzip, br\r\n",
+      `host: ${addr}\r\n\r\n`,
+    ].join("");
+    assertEquals(actual, expected);
+  },
+);
+
+Deno.test(
+  {
+    permissions: { net: true },
+  },
+  async function fetchRequestAcceptHeaders() {
+    const addr = "127.0.0.1:4501";
+    const bufPromise = bufferServer(addr);
+    const response = await fetch(`http://${addr}/blah`, {
+      method: "POST",
+      headers: [
+        ["Accept", "text/html"],
+        ["Accept-Language", "en-US"],
+      ],
+    });
+    await response.arrayBuffer();
+    assertEquals(response.status, 404);
+    assertEquals(response.headers.get("Content-Length"), "2");
+
+    const actual = new TextDecoder().decode((await bufPromise).bytes());
+    const expected = [
+      "POST /blah HTTP/1.1\r\n",
+      "content-length: 0\r\n",
+      "accept: text/html\r\n",
+      "accept-language: en-US\r\n",
       `user-agent: Deno/${Deno.version.deno}\r\n`,
       "accept-encoding: gzip, br\r\n",
       `host: ${addr}\r\n\r\n`,
@@ -678,6 +711,7 @@ Deno.test(
       "foo: Bar\r\n",
       "content-type: text/plain;charset=UTF-8\r\n",
       "accept: */*\r\n",
+      "accept-language: *\r\n",
       `user-agent: Deno/${Deno.version.deno}\r\n`,
       "accept-encoding: gzip, br\r\n",
       `host: ${addr}\r\n`,
@@ -715,6 +749,7 @@ Deno.test(
       "hello: World\r\n",
       "foo: Bar\r\n",
       "accept: */*\r\n",
+      "accept-language: *\r\n",
       `user-agent: Deno/${Deno.version.deno}\r\n`,
       "accept-encoding: gzip, br\r\n",
       `host: ${addr}\r\n`,
@@ -1072,6 +1107,7 @@ Deno.test(
       "hello: World\r\n",
       "foo: Bar\r\n",
       "accept: */*\r\n",
+      "accept-language: *\r\n",
       `user-agent: Deno/${Deno.version.deno}\r\n`,
       "accept-encoding: gzip, br\r\n",
       `host: ${addr}\r\n`,
diff --git a/ext/fetch/26_fetch.js b/ext/fetch/26_fetch.js
index 7ef9bdaf70..9a4916e21f 100644
--- a/ext/fetch/26_fetch.js
+++ b/ext/fetch/26_fetch.js
@@ -452,6 +452,10 @@
         ArrayPrototypePush(request.headerList, ["Accept", "*/*"]);
       }
 
+      if (!requestObject.headers.has("Accept-Language")) {
+        ArrayPrototypePush(request.headerList, ["Accept-Language", "*"]);
+      }
+
       // 12.
       opPromise = PromisePrototypeCatch(
         PromisePrototypeThen(
diff --git a/tools/wpt/expectation.json b/tools/wpt/expectation.json
index 3b25e5fbb7..df2f246551 100644
--- a/tools/wpt/expectation.json
+++ b/tools/wpt/expectation.json
@@ -3018,12 +3018,8 @@
         ],
         "text-utf8.any.html": true,
         "text-utf8.any.worker.html": true,
-        "accept-header.any.html": [
-          "Request through fetch should have a 'accept-language' header"
-        ],
-        "accept-header.any.worker.html": [
-          "Request through fetch should have a 'accept-language' header"
-        ],
+        "accept-header.any.html": true,
+        "accept-header.any.worker.html": true,
         "conditional-get.any.html": false,
         "conditional-get.any.worker.html": false,
         "error-after-response.any.html": false,
@@ -4613,4 +4609,4 @@
     "idlharness.https.any.worker.html": true,
     "idlharness-shadowrealm.window.html": false
   }
-}
+}
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