Stabilize Windows cmd-based shell test harnesses

codex-rs/core/src/codex.rs

@@ -370,6 +370,7 @@ pub(crate) struct CodexSpawnArgs {
     pub(crate) persist_extended_history: bool,
     pub(crate) metrics_service_name: Option<String>,
     pub(crate) inherited_shell_snapshot: Option<Arc<ShellSnapshot>>,
+    pub(crate) user_shell_override: Option<shell::Shell>,
     pub(crate) parent_trace: Option<W3cTraceContext>,
 }
 
@@ -421,6 +422,7 @@ impl Codex {
             persist_extended_history,
             metrics_service_name,
             inherited_shell_snapshot,
+            user_shell_override,
             parent_trace: _,
         } = args;
         let (tx_sub, rx_sub) = async_channel::bounded(SUBMISSION_CHANNEL_CAPACITY);
@@ -575,6 +577,7 @@ impl Codex {
             dynamic_tools,
             persist_extended_history,
             inherited_shell_snapshot,
+            user_shell_override,
         };
 
         // Generate a unique ID for the lifetime of this Codex session.
@@ -1037,6 +1040,7 @@ pub(crate) struct SessionConfiguration {
     dynamic_tools: Vec<DynamicToolSpec>,
     persist_extended_history: bool,
     inherited_shell_snapshot: Option<Arc<ShellSnapshot>>,
+    user_shell_override: Option<shell::Shell>,
 }
 
 impl SessionConfiguration {
@@ -1617,7 +1621,11 @@ impl Session {
         );
 
         let use_zsh_fork_shell = config.features.enabled(Feature::ShellZshFork);
-        let mut default_shell = if use_zsh_fork_shell {
+        let mut default_shell = if let Some(user_shell_override) =
+            session_configuration.user_shell_override.clone()
+        {
+            user_shell_override
+        } else if use_zsh_fork_shell {
             let zsh_path = config.zsh_path.as_ref().ok_or_else(|| {
                 anyhow::anyhow!(
                     "zsh fork feature enabled, but `zsh_path` is not configured; set `zsh_path` in config.toml"

codex-rs/core/src/codex_delegate.rs

@@ -88,6 +88,7 @@ pub(crate) async fn run_codex_thread_interactive(
         persist_extended_history: false,
         metrics_service_name: None,
         inherited_shell_snapshot: None,
+        user_shell_override: None,
         parent_trace: None,
     })
     .await?;

codex-rs/core/src/codex_tests.rs

@@ -1663,6 +1663,7 @@ async fn set_rate_limits_retains_previous_credits() {
         dynamic_tools: Vec::new(),
         persist_extended_history: false,
         inherited_shell_snapshot: None,
+        user_shell_override: None,
     };
 
     let mut state = SessionState::new(session_configuration);
@@ -1760,6 +1761,7 @@ async fn set_rate_limits_updates_plan_type_when_present() {
         dynamic_tools: Vec::new(),
         persist_extended_history: false,
         inherited_shell_snapshot: None,
+        user_shell_override: None,
     };
 
     let mut state = SessionState::new(session_configuration);
@@ -2115,6 +2117,7 @@ pub(crate) async fn make_session_configuration_for_tests() -> SessionConfigurati
         dynamic_tools: Vec::new(),
         persist_extended_history: false,
         inherited_shell_snapshot: None,
+        user_shell_override: None,
     }
 }
 
@@ -2345,6 +2348,7 @@ async fn session_new_fails_when_zsh_fork_enabled_without_zsh_path() {
         dynamic_tools: Vec::new(),
         persist_extended_history: false,
         inherited_shell_snapshot: None,
+        user_shell_override: None,
     };
 
     let (tx_event, _rx_event) = async_channel::unbounded();
@@ -2439,6 +2443,7 @@ pub(crate) async fn make_session_and_context() -> (Session, TurnContext) {
         dynamic_tools: Vec::new(),
         persist_extended_history: false,
         inherited_shell_snapshot: None,
+        user_shell_override: None,
     };
     let per_turn_config = Session::build_per_turn_config(&session_configuration);
     let model_info = ModelsManager::construct_model_info_offline_for_tests(
@@ -3230,6 +3235,7 @@ pub(crate) async fn make_session_and_context_with_dynamic_tools_and_rx(
         dynamic_tools,
         persist_extended_history: false,
         inherited_shell_snapshot: None,
+        user_shell_override: None,
     };
     let per_turn_config = Session::build_per_turn_config(&session_configuration);
     let model_info = ModelsManager::construct_model_info_offline_for_tests(

codex-rs/core/src/codex_tests_guardian.rs

@@ -452,6 +452,7 @@ async fn guardian_subagent_does_not_inherit_parent_exec_policy_rules() {
         persist_extended_history: false,
         metrics_service_name: None,
         inherited_shell_snapshot: None,
+        user_shell_override: None,
         parent_trace: None,
     })
     .await

codex-rs/core/src/test_support.rs

@@ -64,6 +64,33 @@ pub fn thread_manager_with_models_provider_and_home(
     ThreadManager::with_models_provider_and_home_for_tests(auth, provider, codex_home)
 }
 
+pub async fn start_thread_with_user_shell_override(
+    thread_manager: &ThreadManager,
+    config: Config,
+    user_shell_override: crate::shell::Shell,
+) -> crate::error::Result<crate::NewThread> {
+    thread_manager
+        .start_thread_with_user_shell_override_for_tests(config, user_shell_override)
+        .await
+}
+
+pub async fn resume_thread_from_rollout_with_user_shell_override(
+    thread_manager: &ThreadManager,
+    config: Config,
+    rollout_path: PathBuf,
+    auth_manager: Arc<AuthManager>,
+    user_shell_override: crate::shell::Shell,
+) -> crate::error::Result<crate::NewThread> {
+    thread_manager
+        .resume_thread_from_rollout_with_user_shell_override_for_tests(
+            config,
+            rollout_path,
+            auth_manager,
+            user_shell_override,
+        )
+        .await
+}
+
 pub fn models_manager_with_provider(
     codex_home: PathBuf,
     auth_manager: Arc<AuthManager>,

codex-rs/core/src/thread_manager.rs

@@ -381,6 +381,7 @@ impl ThreadManager {
             persist_extended_history,
             metrics_service_name,
             parent_trace,
+            /*user_shell_override*/ None,
         ))
         .await
     }
@@ -420,6 +421,48 @@ impl ThreadManager {
             persist_extended_history,
             /*metrics_service_name*/ None,
             parent_trace,
+            /*user_shell_override*/ None,
+        ))
+        .await
+    }
+
+    pub(crate) async fn start_thread_with_user_shell_override_for_tests(
+        &self,
+        config: Config,
+        user_shell_override: crate::shell::Shell,
+    ) -> CodexResult<NewThread> {
+        Box::pin(self.state.spawn_thread(
+            config,
+            InitialHistory::New,
+            Arc::clone(&self.state.auth_manager),
+            self.agent_control(),
+            Vec::new(),
+            /*persist_extended_history*/ false,
+            /*metrics_service_name*/ None,
+            /*parent_trace*/ None,
+            /*user_shell_override*/ Some(user_shell_override),
+        ))
+        .await
+    }
+
+    pub(crate) async fn resume_thread_from_rollout_with_user_shell_override_for_tests(
+        &self,
+        config: Config,
+        rollout_path: PathBuf,
+        auth_manager: Arc<AuthManager>,
+        user_shell_override: crate::shell::Shell,
+    ) -> CodexResult<NewThread> {
+        let initial_history = RolloutRecorder::get_rollout_history(&rollout_path).await?;
+        Box::pin(self.state.spawn_thread(
+            config,
+            initial_history,
+            auth_manager,
+            self.agent_control(),
+            Vec::new(),
+            /*persist_extended_history*/ false,
+            /*metrics_service_name*/ None,
+            /*parent_trace*/ None,
+            /*user_shell_override*/ Some(user_shell_override),
         ))
         .await
     }
@@ -505,6 +548,7 @@ impl ThreadManager {
             persist_extended_history,
             /*metrics_service_name*/ None,
             parent_trace,
+            /*user_shell_override*/ None,
         ))
         .await
     }
@@ -590,6 +634,7 @@ impl ThreadManagerState {
             metrics_service_name,
             inherited_shell_snapshot,
             /*parent_trace*/ None,
+            /*user_shell_override*/ None,
         ))
         .await
     }
@@ -614,6 +659,7 @@ impl ThreadManagerState {
             /*metrics_service_name*/ None,
             inherited_shell_snapshot,
             /*parent_trace*/ None,
+            /*user_shell_override*/ None,
         ))
         .await
     }
@@ -638,6 +684,7 @@ impl ThreadManagerState {
             /*metrics_service_name*/ None,
             inherited_shell_snapshot,
             /*parent_trace*/ None,
+            /*user_shell_override*/ None,
         ))
         .await
     }
@@ -654,6 +701,7 @@ impl ThreadManagerState {
         persist_extended_history: bool,
         metrics_service_name: Option<String>,
         parent_trace: Option<W3cTraceContext>,
+        user_shell_override: Option<crate::shell::Shell>,
     ) -> CodexResult<NewThread> {
         Box::pin(self.spawn_thread_with_source(
             config,
@@ -666,6 +714,7 @@ impl ThreadManagerState {
             metrics_service_name,
             /*inherited_shell_snapshot*/ None,
             parent_trace,
+            user_shell_override,
         ))
         .await
     }
@@ -683,6 +732,7 @@ impl ThreadManagerState {
         metrics_service_name: Option<String>,
         inherited_shell_snapshot: Option<Arc<ShellSnapshot>>,
         parent_trace: Option<W3cTraceContext>,
+        user_shell_override: Option<crate::shell::Shell>,
     ) -> CodexResult<NewThread> {
         let watch_registration = self
             .file_watcher
@@ -704,6 +754,7 @@ impl ThreadManagerState {
             persist_extended_history,
             metrics_service_name,
             inherited_shell_snapshot,
+            user_shell_override,
             parent_trace,
         })
         .await?;

codex-rs/core/tests/common/test_codex.rs

@@ -13,6 +13,8 @@ use codex_core::built_in_model_providers;
 use codex_core::config::Config;
 use codex_core::features::Feature;
 use codex_core::models_manager::collaboration_mode_presets::CollaborationModesConfig;
+use codex_core::shell::Shell;
+use codex_core::shell::get_shell_by_model_provided_path;
 use codex_protocol::config_types::ServiceTier;
 use codex_protocol::openai_models::ModelsResponse;
 use codex_protocol::protocol::AskForApproval;
@@ -64,6 +66,7 @@ pub struct TestCodexBuilder {
     auth: CodexAuth,
     pre_build_hooks: Vec<Box<PreBuildHook>>,
     home: Option<Arc<TempDir>>,
+    user_shell_override: Option<Shell>,
 }
 
 impl TestCodexBuilder {
@@ -100,6 +103,19 @@ impl TestCodexBuilder {
         self
     }
 
+    pub fn with_user_shell(mut self, user_shell: Shell) -> Self {
+        self.user_shell_override = Some(user_shell);
+        self
+    }
+
+    pub fn with_windows_cmd_shell(self) -> Self {
+        if cfg!(windows) {
+            self.with_user_shell(get_shell_by_model_provided_path(&PathBuf::from("cmd.exe")))
+        } else {
+            self
+        }
+    }
+
     pub async fn build(&mut self, server: &wiremock::MockServer) -> anyhow::Result<TestCodex> {
         let home = match self.home.clone() {
             Some(home) => home,
@@ -199,9 +215,23 @@ impl TestCodexBuilder {
             )
         };
         let thread_manager = Arc::new(thread_manager);
+        let user_shell_override = self.user_shell_override.clone();
 
-        let new_conversation = match resume_from {
-            Some(path) => {
+        let new_conversation = match (resume_from, user_shell_override) {
+            (Some(path), Some(user_shell_override)) => {
+                let auth_manager = codex_core::test_support::auth_manager_from_auth(auth);
+                Box::pin(
+                    codex_core::test_support::resume_thread_from_rollout_with_user_shell_override(
+                        thread_manager.as_ref(),
+                        config.clone(),
+                        path,
+                        auth_manager,
+                        user_shell_override,
+                    ),
+                )
+                .await?
+            }
+            (Some(path), None) => {
                 let auth_manager = codex_core::test_support::auth_manager_from_auth(auth);
                 Box::pin(thread_manager.resume_thread_from_rollout(
                     config.clone(),
@@ -211,7 +241,17 @@ impl TestCodexBuilder {
                 ))
                 .await?
             }
-            None => Box::pin(thread_manager.start_thread(config.clone())).await?,
+            (None, Some(user_shell_override)) => {
+                Box::pin(
+                    codex_core::test_support::start_thread_with_user_shell_override(
+                        thread_manager.as_ref(),
+                        config.clone(),
+                        user_shell_override,
+                    ),
+                )
+                .await?
+            }
+            (None, None) => Box::pin(thread_manager.start_thread(config.clone())).await?,
         };
 
         Ok(TestCodex {
@@ -562,6 +602,7 @@ pub fn test_codex() -> TestCodexBuilder {
         auth: CodexAuth::from_api_key("dummy"),
         pre_build_hooks: vec![],
         home: None,
+        user_shell_override: None,
     }
 }
 

codex-rs/core/tests/suite/agent_websocket.rs

@@ -35,7 +35,7 @@ async fn websocket_test_codex_shell_chain() -> Result<()> {
     ]])
     .await;
 
-    let mut builder = test_codex();
+    let mut builder = test_codex().with_windows_cmd_shell();
 
     let test = builder.build_with_websocket_server(&server).await?;
     test.submit_turn_with_policy(
@@ -183,7 +183,7 @@ async fn websocket_v2_test_codex_shell_chain() -> Result<()> {
     ]])
     .await;
 
-    let mut builder = test_codex().with_config(|config| {
+    let mut builder = test_codex().with_windows_cmd_shell().with_config(|config| {
         config
             .features
             .enable(Feature::ResponsesWebsocketsV2)