Update client to use new Node header features

Author: pimterry

src/client/client-types.ts

@@ -53,7 +53,7 @@ export interface RequestOptions {
      * Each certificate should be an object with a `cert` key containing the PEM
      * certificate as a string.
      */
-    additionalTrustedCAs: Array<{ cert: string }>;
+    additionalTrustedCAs?: Array<{ cert: string }>;
 
     /**
      * Deprecated alias for `additionalTrustedCAs`

src/client/http-client.ts

@@ -84,6 +84,9 @@ export class HttpClient {
             method: requestDefn.method,
             signal: options.abortSignal,
 
+            setDefaultHeaders: false,
+            headers: flattenPairedRawHeaders(requestDefn.headers),
+
             // Low-level connection configuration:
             agent,
             lookup: this.getDns(options.lookupOptions?.servers),
@@ -101,7 +104,7 @@ export class HttpClient {
                     ? tls.rootCertificates.concat(additionalCAs.map(({ cert }) => cert))
                     : undefined
             })
-        });
+        } as any); // Would be nice to avoid this but raw header options aren't in the types yet
 
         if (options.keyLogFile) {
             request.on('socket', (socket) => {
@@ -114,19 +117,6 @@ export class HttpClient {
             request.abort();
         });
 
-        // Node supports sending raw headers via [key, value, key, value] array, but if we do
-        // so with 'headers' above then we can't removeHeader first (to disable the defaults).
-        // Instead we remove headers and then manually trigger the 'raw' write behaviour.
-
-        request.removeHeader('connection');
-        request.removeHeader('transfer-encoding');
-        request.removeHeader('content-length');
-
-        (request as any)._storeHeader(
-            request.method + ' ' + request.path + ' HTTP/1.1\r\n',
-            flattenPairedRawHeaders(requestDefn.headers)
-        );
-
         if (requestDefn.rawBody?.byteLength) {
             request.end(requestDefn.rawBody);
         } else {