From bcdfe82995862c6726cd396cd0a625c0c3844b3d Mon Sep 17 00:00:00 2001
From: Marcin Jahn <marcin.jahn@esky.com>
Date: Sat, 21 Jan 2023 10:05:27 +0100
Subject: [PATCH] fix(http) Remove outgoing headers normalization

---
 experimental/CHANGELOG.md                                 | 2 ++
 .../opentelemetry-instrumentation-http/src/utils.ts       | 8 --------
 .../test/functionals/http-enable.test.ts                  | 5 -----
 .../test/functionals/https-enable.test.ts                 | 7 +------
 4 files changed, 3 insertions(+), 19 deletions(-)

diff --git a/experimental/CHANGELOG.md b/experimental/CHANGELOG.md
index 9416823ca2a..bf48c1b9dc4 100644
--- a/experimental/CHANGELOG.md
+++ b/experimental/CHANGELOG.md
@@ -10,6 +10,8 @@ All notable changes to experimental packages in this project will be documented
 
 ### :bug: (Bug Fix)
 
+* fix(http) Remove outgoing headers normalization [#3557](/~https://github.com/open-telemetry/opentelemetry-js/pull/3557) @marcinjahn
+
 ### :books: (Refine Doc)
 
 ### :house: (Internal)
diff --git a/experimental/packages/opentelemetry-instrumentation-http/src/utils.ts b/experimental/packages/opentelemetry-instrumentation-http/src/utils.ts
index 4f91ad4cfdc..c9a178653ef 100644
--- a/experimental/packages/opentelemetry-instrumentation-http/src/utils.ts
+++ b/experimental/packages/opentelemetry-instrumentation-http/src/utils.ts
@@ -276,14 +276,6 @@ export const getRequestInfo = (
     origin = `${optionsParsed.protocol || 'http:'}//${hostname}`;
   }
 
-  const headers = optionsParsed.headers ?? {};
-  optionsParsed.headers = Object.keys(headers).reduce(
-    (normalizedHeader, key) => {
-      normalizedHeader[key.toLowerCase()] = headers[key];
-      return normalizedHeader;
-    },
-    {} as OutgoingHttpHeaders
-  );
   // some packages return method in lowercase..
   // ensure upperCase for consistency
   const method = optionsParsed.method
diff --git a/experimental/packages/opentelemetry-instrumentation-http/test/functionals/http-enable.test.ts b/experimental/packages/opentelemetry-instrumentation-http/test/functionals/http-enable.test.ts
index fb10580739c..9ebfe41c80f 100644
--- a/experimental/packages/opentelemetry-instrumentation-http/test/functionals/http-enable.test.ts
+++ b/experimental/packages/opentelemetry-instrumentation-http/test/functionals/http-enable.test.ts
@@ -508,11 +508,6 @@ describe('HttpInstrumentation', () => {
               'user-agent': testValue,
             },
           }),
-          httpRequest.get(`${protocol}://${hostname}:${serverPort}`, {
-            headers: {
-              'uSeR-aGeNt': testValue,
-            },
-          }),
         ]);
         const spans = memoryExporter.getFinishedSpans();
         assert.strictEqual(spans.length, 0);
diff --git a/experimental/packages/opentelemetry-instrumentation-http/test/functionals/https-enable.test.ts b/experimental/packages/opentelemetry-instrumentation-http/test/functionals/https-enable.test.ts
index 8ca18c5e984..78e497487ee 100644
--- a/experimental/packages/opentelemetry-instrumentation-http/test/functionals/https-enable.test.ts
+++ b/experimental/packages/opentelemetry-instrumentation-http/test/functionals/https-enable.test.ts
@@ -459,12 +459,7 @@ describe('HttpsInstrumentation', () => {
             headers: {
               'user-agent': testValue,
             },
-          }),
-          httpsRequest.get(`${protocol}://${hostname}:${serverPort}`, {
-            headers: {
-              'uSeR-aGeNt': testValue,
-            },
-          }),
+          })
         ]);
         const spans = memoryExporter.getFinishedSpans();
         assert.strictEqual(spans.length, 0);