patch capture issues

scripts/patch-node-modules.sh

@@ -120,4 +120,30 @@ redirect_ws_to_real_package() {
 echo "==> [node_modules] redirecting ws requires past bun's built-in shim"
 redirect_ws_to_real_package node_modules/mockttp/dist
 
+# mockttp decides whether a response is still ongoing or already completed by
+# sniffing the object's shape:
+#
+#   // Ongoing response has 'getHeaders' - completed has 'headers'.
+#   if ('headers' in response) return response;
+#
+# An ongoing response is a live http.ServerResponse; a completed one is the plain
+# object built by buildInitiatedResponse(). On node that test works, because
+# ServerResponse has no `headers` property. Bun's ServerResponse *does* have one
+# (`'headers' in res` === true, typeof object), so the check is inverted for every
+# single response: waitForCompletedResponse() bails out immediately and hands back
+# the live ServerResponse, having neither awaited the body nor attached rawHeaders.
+#
+# The admin server then tries to serialise that as a GraphQL Response, whose
+# schema declares `rawHeaders: Json!`, and the whole responseCompleted event is
+# dropped with "Cannot return null for non-nullable field Response.rawHeaders."
+# Traffic still proxies correctly - but the UI only ever receives the *initiated*
+# response, so exchanges render with status and headers and no body, forever.
+#
+# Testing for the ongoing-response method instead is unambiguous under either
+# runtime: a completed response is a plain object and has no getHeaders.
+echo "==> [node_modules] fixing mockttp's ongoing-vs-completed response check for bun"
+replace_literal node_modules/mockttp/dist/util/request-utils.js \
+    "if ('headers' in response)" \
+    "if (typeof response.getHeaders !== 'function')"
+
 echo "==> patch-node-modules.sh complete."