WIP: test windows PTY

codex-rs/.config/nextest.toml

@@ -11,3 +11,7 @@ slow-timeout = { period = "1m", terminate-after = 4 }
 [[profile.default.overrides]]
 filter = 'test(approval_matrix_covers_all_modes)'
 slow-timeout = { period = "30s", terminate-after = 2 }
+
+[[profile.default.overrides]]
+filter = 'test(windows_unified_exec)'
+slow-timeout = { period = "30s", terminate-after = 4 }

codex-rs/core/Cargo.toml

@@ -59,6 +59,7 @@ shlex = { workspace = true }
 similar = { workspace = true }
 strum_macros = { workspace = true }
 url = { workspace = true }
+vt100 = { workspace = true }
 once_cell = { workspace = true }
 regex = { workspace = true }
 tempfile = { workspace = true }

codex-rs/core/src/unified_exec/mod.rs

@@ -234,13 +234,12 @@ mod tests {
 
         assert_eq!(buffer.total_bytes, UNIFIED_EXEC_OUTPUT_MAX_BYTES);
         let snapshot = buffer.snapshot();
-        assert_eq!(snapshot.len(), 3);
+        assert_eq!(snapshot.len(), 2);
         assert_eq!(
             snapshot.first().unwrap().len(),
             UNIFIED_EXEC_OUTPUT_MAX_BYTES - 2
         );
-        assert_eq!(snapshot.get(2).unwrap(), &vec![b'c']);
-        assert_eq!(snapshot.get(1).unwrap(), &vec![b'b']);
+        assert_eq!(snapshot.get(1).unwrap(), &vec![b'b', b'c']);
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]

codex-rs/core/src/unified_exec/session.rs

@@ -31,8 +31,25 @@ pub(crate) struct OutputBufferState {
 
 impl OutputBufferState {
     pub(super) fn push_chunk(&mut self, chunk: Vec<u8>) {
-        self.total_bytes = self.total_bytes.saturating_add(chunk.len());
-        self.chunks.push_back(chunk);
+        if chunk.is_empty() {
+            return;
+        }
+
+        // On Windows (especially with ConPTY) output can arrive in many tiny chunks.
+        // Coalesce them to avoid pathological behavior in drain/collect paths.
+        const MAX_COALESCED_CHUNK_BYTES: usize = 8_192;
+
+        let mut chunk = chunk;
+        let chunk_len = chunk.len();
+        self.total_bytes = self.total_bytes.saturating_add(chunk_len);
+
+        if let Some(tail) = self.chunks.back_mut()
+            && tail.len().saturating_add(chunk_len) <= MAX_COALESCED_CHUNK_BYTES
+        {
+            tail.append(&mut chunk);
+        } else {
+            self.chunks.push_back(chunk);
+        }
 
         let mut excess = self
             .total_bytes

codex-rs/core/src/unified_exec/session_manager.rs

@@ -62,6 +62,17 @@ const UNIFIED_EXEC_ENV: [(&str, &str); 8] = [
     ("GIT_PAGER", "cat"),
 ];
 
+fn normalize_unified_exec_text(raw: &str) -> String {
+    if cfg!(target_os = "windows") {
+        let mut parser = vt100::Parser::new(40, 120, 1_024);
+        parser.process(raw.as_bytes());
+        parser.screen_mut().set_scrollback(usize::MAX);
+        return parser.screen().contents();
+    }
+
+    raw.to_string()
+}
+
 fn apply_unified_exec_env(mut env: HashMap<String, String>) -> HashMap<String, String> {
     for (key, value) in UNIFIED_EXEC_ENV {
         env.insert(key.to_string(), value.to_string());
@@ -163,7 +174,8 @@ impl UnifiedExecSessionManager {
         .await;
         let wall_time = Instant::now().saturating_duration_since(start);
 
-        let text = String::from_utf8_lossy(&collected).to_string();
+        let raw_text = String::from_utf8_lossy(&collected).to_string();
+        let text = normalize_unified_exec_text(&raw_text);
         let output = formatted_truncate_text(&text, TruncationPolicy::Tokens(max_tokens));
         let has_exited = session.has_exited();
         let exit_code = session.exit_code();
@@ -285,7 +297,8 @@ impl UnifiedExecSessionManager {
         .await;
         let wall_time = Instant::now().saturating_duration_since(start);
 
-        let text = String::from_utf8_lossy(&collected).to_string();
+        let raw_text = String::from_utf8_lossy(&collected).to_string();
+        let text = normalize_unified_exec_text(&raw_text);
         let output = formatted_truncate_text(&text, TruncationPolicy::Tokens(max_tokens));
         let original_token_count = approx_token_count(&text);
         let chunk_id = generate_chunk_id();