[BUG]: invalid header name cause runtime error

[Doctor-wu]

Tracer Version(s)

5.48.1

Node.js Version(s)

23.11.1

Bug Report

invalid header cause runtime error

https://github.com/DataDog/dd-trace-js/blob/master/packages/datadog-plugin-fetch/src/index.js#L21

https://developer.mozilla.org/en-US/docs/Web/API/Headers/has

We should handle the invalid header properly here

Reproduction Code

No response

Error Logs

No response

Tracer Config

No response

Operating System

No response

Bundling

Vite

[RexSkz]

More specifically, headers.has may throw TypeError when a header is invalid, if dd trace can't catch this error, Node.js thread will crash.

We solved it temporarily by patching the library:

diff --git a/packages/datadog-plugin-fetch/src/index.js b/packages/datadog-plugin-fetch/src/index.js
index 943a1908ddb2235f3172d3ab8c9498400f37c257..26b9fd240966a0e2e9fd5511080fdd6feaaa654d 100644
--- a/packages/datadog-plugin-fetch/src/index.js
+++ b/packages/datadog-plugin-fetch/src/index.js
@@ -18,8 +18,13 @@ class FetchPlugin extends HttpClientPlugin {
     const store = super.bindStart(ctx)
 
     for (const name in options.headers) {
-      if (!req.headers.has(name)) {
-        req.headers.set(name, options.headers[name])
+      // prevent potential crash caused by `headers.has` in node.js
+      try {
+        if (!req.headers.has(name)) {
+          req.headers.set(name, options.headers[name])
+        }
+      } catch {
+        // ignore
       }
     }