Extract Responses header conversion into a shared module (#48200)

Move JSON-to-HTTP header conversion from `responses_websocket` into the
crate-wide `responses_headers` module and update the WebSocket code to use it.
Preserve conversion of string, number, and boolean values, while continuing to
ignore invalid header names and unsupported or invalid values.

GitOrigin-RevId: f179de214cf763549b5b8a898dc4bcda3ce07ebd

codex-rs/codex-api/src/endpoint/responses_websocket.rs

@@ -7,6 +7,7 @@ use crate::common::WS_REQUEST_HEADER_TRACEPARENT_CLIENT_METADATA_KEY;
 use crate::error::ApiError;
 use crate::provider::Provider;
 use crate::rate_limits::parse_rate_limit_event;
+use crate::responses_headers::json_headers_to_http_headers;
 use crate::safety_buffering::treatment_from_headers;
 use crate::sse::ResponsesStreamEvent;
 use crate::sse::process_responses_event;
@@ -18,8 +19,6 @@ use codex_websocket_client::WebSocketConnector;
 use futures::SinkExt;
 use futures::StreamExt;
 use http::HeaderMap;
-use http::HeaderName;
-use http::HeaderValue;
 use http::StatusCode;
 use serde::Deserialize;
 use serde_json::Value;
@@ -660,30 +659,6 @@ fn map_wrapped_websocket_error_event(
     }))
 }
 
-fn json_headers_to_http_headers(headers: &JsonMap<String, Value>) -> HeaderMap {
-    let mut mapped = HeaderMap::new();
-    for (name, value) in headers {
-        let Ok(header_name) = HeaderName::from_bytes(name.as_bytes()) else {
-            continue;
-        };
-        let Some(header_value) = json_header_value(value) else {
-            continue;
-        };
-        mapped.insert(header_name, header_value);
-    }
-    mapped
-}
-
-fn json_header_value(value: &Value) -> Option<HeaderValue> {
-    let value = match value {
-        Value::String(value) => value.clone(),
-        Value::Number(value) => value.to_string(),
-        Value::Bool(value) => value.to_string(),
-        _ => return None,
-    };
-    HeaderValue::from_str(&value).ok()
-}
-
 async fn run_websocket_response_stream(
     ws_stream: &mut WsStream,
     tx_event: mpsc::Sender<std::result::Result<ResponseEvent, ApiError>>,
@@ -930,6 +905,7 @@ mod tests {
     use codex_protocol::ResponseItemId;
     use codex_protocol::models::ContentItem;
     use codex_protocol::models::ResponseItem;
+    use http::HeaderValue;
     use pretty_assertions::assert_eq;
     use serde_json::json;
     use serde_json::value::RawValue;

codex-rs/codex-api/src/lib.rs

@@ -8,6 +8,7 @@ pub(crate) mod images;
 pub(crate) mod provider;
 pub(crate) mod rate_limits;
 pub(crate) mod requests;
+mod responses_headers;
 pub(crate) mod safety_buffering;
 pub(crate) mod search;
 pub(crate) mod sse;

codex-rs/codex-api/src/responses_headers.rs

@@ -0,0 +1,32 @@
+//! Converts headers in Responses event payloads to HTTP headers.
+//! Invalid names and unsupported or invalid values are ignored.
+
+use http::HeaderMap;
+use http::HeaderName;
+use http::HeaderValue;
+use serde_json::Value;
+use serde_json::map::Map as JsonMap;
+
+pub(crate) fn json_headers_to_http_headers(headers: &JsonMap<String, Value>) -> HeaderMap {
+    let mut mapped = HeaderMap::new();
+    for (name, value) in headers {
+        let Ok(header_name) = HeaderName::from_bytes(name.as_bytes()) else {
+            continue;
+        };
+        let Some(header_value) = json_header_value(value) else {
+            continue;
+        };
+        mapped.insert(header_name, header_value);
+    }
+    mapped
+}
+
+fn json_header_value(value: &Value) -> Option<HeaderValue> {
+    let value = match value {
+        Value::String(value) => value.clone(),
+        Value::Number(value) => value.to_string(),
+        Value::Bool(value) => value.to_string(),
+        _ => return None,
+    };
+    HeaderValue::from_str(&value).ok()
+}