feat: codex exec auto-subscribe to new threads (#9821)

codex-rs/exec/src/main.rs

@@ -38,3 +38,44 @@ fn main() -> anyhow::Result<()> {
         Ok(())
     })
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn top_cli_parses_resume_prompt_after_config_flag() {
+        const PROMPT: &str = "echo resume-with-global-flags-after-subcommand";
+        let cli = TopCli::parse_from([
+            "codex-exec",
+            "resume",
+            "--last",
+            "--json",
+            "--model",
+            "gpt-5.2-codex",
+            "--config",
+            "reasoning_level=xhigh",
+            "--dangerously-bypass-approvals-and-sandbox",
+            "--skip-git-repo-check",
+            PROMPT,
+        ]);
+
+        let Some(codex_exec::Command::Resume(args)) = cli.inner.command else {
+            panic!("expected resume command");
+        };
+        let effective_prompt = args.prompt.clone().or_else(|| {
+            if args.last {
+                args.session_id.clone()
+            } else {
+                None
+            }
+        });
+        assert_eq!(effective_prompt.as_deref(), Some(PROMPT));
+        assert_eq!(cli.config_overrides.raw_overrides.len(), 1);
+        assert_eq!(
+            cli.config_overrides.raw_overrides[0],
+            "reasoning_level=xhigh"
+        );
+    }
+}