fix: integration test for #9011 (#9166)

Adds an integration test for the new behavior introduced in
https://github.com/openai/codex/pull/9011. The work to create the test
setup was substantial enough that I thought it merited a separate PR.

This integration test spawns `codex` in TUI mode, which requires
spawning a PTY to run successfully, so I had to introduce quite a bit of
scaffolding in `run_codex_cli()`. I was surprised to discover that we
have not done this in our codebase before, so perhaps this should get
moved to a common location so it can be reused.

The test itself verifies that a malformed `rules` in `$CODEX_HOME`
prints a human-readable error message and exits nonzero.

codex-rs/Cargo.lock

@@ -1746,6 +1746,7 @@ dependencies = [
  "codex-app-server-protocol",
  "codex-arg0",
  "codex-backend-client",
+ "codex-cli",
  "codex-common",
  "codex-core",
  "codex-feedback",
@@ -1753,6 +1754,8 @@ dependencies = [
  "codex-login",
  "codex-protocol",
  "codex-utils-absolute-path",
+ "codex-utils-cargo-bin",
+ "codex-utils-pty",
  "codex-windows-sandbox",
  "color-eyre",
  "crossterm",
@@ -1818,6 +1821,7 @@ dependencies = [
  "codex-app-server-protocol",
  "codex-arg0",
  "codex-backend-client",
+ "codex-cli",
  "codex-common",
  "codex-core",
  "codex-feedback",
@@ -1826,6 +1830,8 @@ dependencies = [
  "codex-protocol",
  "codex-tui",
  "codex-utils-absolute-path",
+ "codex-utils-cargo-bin",
+ "codex-utils-pty",
  "codex-windows-sandbox",
  "color-eyre",
  "crossterm",

codex-rs/Cargo.toml

@@ -71,6 +71,7 @@ codex-arg0 = { path = "arg0" }
 codex-async-utils = { path = "async-utils" }
 codex-backend-client = { path = "backend-client" }
 codex-chatgpt = { path = "chatgpt" }
+codex-cli = { path = "cli"}
 codex-client = { path = "codex-client" }
 codex-common = { path = "common" }
 codex-core = { path = "core" }

codex-rs/tui/BUILD.bazel

@@ -14,4 +14,7 @@ codex_rust_crate(
     ),
     test_data_extra = glob(["src/**/snapshots/**"]),
     integration_compile_data_extra = ["src/test_backend.rs"],
+    extra_binaries = [
+        "//codex-rs/cli:codex",
+    ],
 )

codex-rs/tui/Cargo.toml

@@ -113,7 +113,10 @@ arboard = { workspace = true }
 
 
 [dev-dependencies]
+codex-cli = { workspace = true }
 codex-core = { workspace = true, features = ["test-support"] }
+codex-utils-cargo-bin = { workspace = true }
+codex-utils-pty = { workspace = true }
 assert_matches = { workspace = true }
 chrono = { workspace = true, features = ["serde"] }
 insta = { workspace = true }

codex-rs/tui/tests/all.rs

@@ -3,4 +3,7 @@
 #[cfg(feature = "vt100-tests")]
 mod test_backend;
 
+#[allow(unused_imports)]
+use codex_cli as _; // Keep dev-dep for cargo-shear; tests spawn the codex binary.
+
 mod suite;

codex-rs/tui/tests/suite/mod.rs

@@ -1,4 +1,5 @@
 // Aggregates all former standalone integration tests as modules.
+mod no_panic_on_startup;
 mod status_indicator;
 mod vt100_history;
 mod vt100_live_commit;

codex-rs/tui/tests/suite/no_panic_on_startup.rs

@@ -0,0 +1,119 @@
+use std::collections::HashMap;
+use std::path::Path;
+use std::time::Duration;
+use tokio::select;
+use tokio::time::timeout;
+
+/// Regression test for https://github.com/openai/codex/issues/8803.
+#[tokio::test]
+async fn malformed_rules_should_not_panic() -> anyhow::Result<()> {
+    // run_codex_cli() does not work on Windows due to PTY limitations.
+    if cfg!(windows) {
+        return Ok(());
+    }
+
+    let tmp = tempfile::tempdir()?;
+    let codex_home = tmp.path();
+    std::fs::write(
+        codex_home.join("rules"),
+        "rules should be a directory not a file",
+    )?;
+
+    // TODO(mbolin): Figure out why using a temp dir as the cwd causes this test
+    // to hang.
+    let cwd = std::env::current_dir()?;
+    let config_contents = format!(
+        r#"
+# Pick a local provider so the CLI doesn't prompt for OpenAI auth in this test.
+model_provider = "ollama"
+
+[projects]
+"{cwd}" = {{ trust_level = "trusted" }}
+"#,
+        cwd = cwd.display()
+    );
+    std::fs::write(codex_home.join("config.toml"), config_contents)?;
+
+    let CodexCliOutput { exit_code, output } = run_codex_cli(codex_home, cwd).await?;
+    assert_eq!(1, exit_code, "Codex CLI should exit nonzero.");
+    assert!(
+        output.contains("ERROR: Failed to initialize codex:"),
+        "expected startup error in output, got: {output}"
+    );
+    assert!(
+        output.contains("failed to read execpolicy files"),
+        "expected execpolicy read error in output, got: {output}"
+    );
+    Ok(())
+}
+
+struct CodexCliOutput {
+    exit_code: i32,
+    output: String,
+}
+
+async fn run_codex_cli(
+    codex_home: impl AsRef<Path>,
+    cwd: impl AsRef<Path>,
+) -> anyhow::Result<CodexCliOutput> {
+    let codex_cli = codex_utils_cargo_bin::cargo_bin("codex")?;
+    let mut env = HashMap::new();
+    env.insert(
+        "CODEX_HOME".to_string(),
+        codex_home.as_ref().display().to_string(),
+    );
+
+    let args = vec!["-c".to_string(), "analytics_enabled=false".to_string()];
+    let spawned = codex_utils_pty::spawn_pty_process(
+        codex_cli.to_string_lossy().as_ref(),
+        &args,
+        cwd.as_ref(),
+        &env,
+        &None,
+    )
+    .await?;
+    let mut output = Vec::new();
+    let mut output_rx = spawned.output_rx;
+    let mut exit_rx = spawned.exit_rx;
+    let writer_tx = spawned.session.writer_sender();
+    let exit_code_result = timeout(Duration::from_secs(10), async {
+        // Read PTY output until the process exits while replying to cursor
+        // position queries so the TUI can initialize without a real terminal.
+        loop {
+            select! {
+                result = output_rx.recv() => match result {
+                    Ok(chunk) => {
+                        // The TUI asks for the cursor position via ESC[6n.
+                        // Respond with a valid position to unblock startup.
+                        if chunk.windows(4).any(|window| window == b"\x1b[6n") {
+                            let _ = writer_tx.send(b"\x1b[1;1R".to_vec()).await;
+                        }
+                        output.extend_from_slice(&chunk);
+                    }
+                    Err(tokio::sync::broadcast::error::RecvError::Closed) => break exit_rx.await,
+                    Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => {}
+                },
+                result = &mut exit_rx => break result,
+            }
+        }
+    })
+    .await;
+    let exit_code = match exit_code_result {
+        Ok(Ok(code)) => code,
+        Ok(Err(err)) => return Err(err.into()),
+        Err(_) => {
+            spawned.session.terminate();
+            anyhow::bail!("timed out waiting for codex CLI to exit");
+        }
+    };
+    // Drain any output that raced with the exit notification.
+    while let Ok(chunk) = output_rx.try_recv() {
+        output.extend_from_slice(&chunk);
+    }
+
+    let output = String::from_utf8_lossy(&output);
+    Ok(CodexCliOutput {
+        exit_code,
+        output: output.to_string(),
+    })
+}

codex-rs/tui2/BUILD.bazel

@@ -14,4 +14,7 @@ codex_rust_crate(
     ),
     test_data_extra = glob(["src/**/snapshots/**"]),
     integration_compile_data_extra = ["src/test_backend.rs"],
+    extra_binaries = [
+        "//codex-rs/cli:codex",
+    ],
 )

codex-rs/tui2/Cargo.toml

@@ -109,7 +109,10 @@ arboard = { workspace = true }
 
 [dev-dependencies]
 assert_matches = { workspace = true }
+codex-cli = { workspace = true }
 codex-core = { workspace = true, features = ["test-support"] }
+codex-utils-cargo-bin = { workspace = true }
+codex-utils-pty = { workspace = true }
 chrono = { workspace = true, features = ["serde"] }
 insta = { workspace = true }
 pretty_assertions = { workspace = true }

codex-rs/tui2/tests/all.rs

@@ -3,4 +3,7 @@
 #[cfg(feature = "vt100-tests")]
 mod test_backend;
 
+#[allow(unused_imports)]
+use codex_cli as _; // Keep dev-dep for cargo-shear; tests spawn the codex binary.
+
 mod suite;

codex-rs/tui2/tests/suite/mod.rs

@@ -1,4 +1,5 @@
 // Aggregates all former standalone integration tests as modules.
+mod no_panic_on_startup;
 mod status_indicator;
 mod vt100_history;
 mod vt100_live_commit;

codex-rs/tui2/tests/suite/no_panic_on_startup.rs

@@ -0,0 +1,119 @@
+use std::collections::HashMap;
+use std::path::Path;
+use std::time::Duration;
+use tokio::select;
+use tokio::time::timeout;
+
+/// Regression test for https://github.com/openai/codex/issues/8803.
+#[tokio::test]
+async fn malformed_rules_should_not_panic() -> anyhow::Result<()> {
+    // run_codex_cli() does not work on Windows due to PTY limitations.
+    if cfg!(windows) {
+        return Ok(());
+    }
+
+    let tmp = tempfile::tempdir()?;
+    let codex_home = tmp.path();
+    std::fs::write(
+        codex_home.join("rules"),
+        "rules should be a directory not a file",
+    )?;
+
+    // TODO(mbolin): Figure out why using a temp dir as the cwd causes this test
+    // to hang.
+    let cwd = std::env::current_dir()?;
+    let config_contents = format!(
+        r#"
+# Pick a local provider so the CLI doesn't prompt for OpenAI auth in this test.
+model_provider = "ollama"
+
+[projects]
+"{cwd}" = {{ trust_level = "trusted" }}
+"#,
+        cwd = cwd.display()
+    );
+    std::fs::write(codex_home.join("config.toml"), config_contents)?;
+
+    let CodexCliOutput { exit_code, output } = run_codex_cli(codex_home, cwd).await?;
+    assert_eq!(1, exit_code, "Codex CLI should exit nonzero.");
+    assert!(
+        output.contains("ERROR: Failed to initialize codex:"),
+        "expected startup error in output, got: {output}"
+    );
+    assert!(
+        output.contains("failed to read execpolicy files"),
+        "expected execpolicy read error in output, got: {output}"
+    );
+    Ok(())
+}
+
+struct CodexCliOutput {
+    exit_code: i32,
+    output: String,
+}
+
+async fn run_codex_cli(
+    codex_home: impl AsRef<Path>,
+    cwd: impl AsRef<Path>,
+) -> anyhow::Result<CodexCliOutput> {
+    let codex_cli = codex_utils_cargo_bin::cargo_bin("codex")?;
+    let mut env = HashMap::new();
+    env.insert(
+        "CODEX_HOME".to_string(),
+        codex_home.as_ref().display().to_string(),
+    );
+
+    let args = vec!["-c".to_string(), "analytics_enabled=false".to_string()];
+    let spawned = codex_utils_pty::spawn_pty_process(
+        codex_cli.to_string_lossy().as_ref(),
+        &args,
+        cwd.as_ref(),
+        &env,
+        &None,
+    )
+    .await?;
+    let mut output = Vec::new();
+    let mut output_rx = spawned.output_rx;
+    let mut exit_rx = spawned.exit_rx;
+    let writer_tx = spawned.session.writer_sender();
+    let exit_code_result = timeout(Duration::from_secs(10), async {
+        // Read PTY output until the process exits while replying to cursor
+        // position queries so the TUI can initialize without a real terminal.
+        loop {
+            select! {
+                result = output_rx.recv() => match result {
+                    Ok(chunk) => {
+                        // The TUI asks for the cursor position via ESC[6n.
+                        // Respond with a valid position to unblock startup.
+                        if chunk.windows(4).any(|window| window == b"\x1b[6n") {
+                            let _ = writer_tx.send(b"\x1b[1;1R".to_vec()).await;
+                        }
+                        output.extend_from_slice(&chunk);
+                    }
+                    Err(tokio::sync::broadcast::error::RecvError::Closed) => break exit_rx.await,
+                    Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => {}
+                },
+                result = &mut exit_rx => break result,
+            }
+        }
+    })
+    .await;
+    let exit_code = match exit_code_result {
+        Ok(Ok(code)) => code,
+        Ok(Err(err)) => return Err(err.into()),
+        Err(_) => {
+            spawned.session.terminate();
+            anyhow::bail!("timed out waiting for codex CLI to exit");
+        }
+    };
+    // Drain any output that raced with the exit notification.
+    while let Ok(chunk) = output_rx.try_recv() {
+        output.extend_from_slice(&chunk);
+    }
+
+    let output = String::from_utf8_lossy(&output);
+    Ok(CodexCliOutput {
+        exit_code,
+        output: output.to_string(),
+    })
+}