test(cli): cover the signed-out chatgpt and --models paths

Author: cloudbridgeuy

crates/llm_stream/tests/cli.rs

@@ -0,0 +1,68 @@
+//! Offline coverage of the CLI's surface.
+//!
+//! Nothing here touches the network or needs credentials — every path asserted
+//! below fails (or answers) before a socket is opened — so these run on any
+//! machine, in CI, for free. Contrast `live_chatgpt.rs`, which is opt-in.
+
+use std::process::{Command, Stdio};
+
+/// The one sentence a signed-out operator should ever see. Duplicated from
+/// `crate::auth::flow::NOT_SIGNED_IN` on purpose: an integration test cannot
+/// import from a binary-only crate, and a test that reads the constant it is
+/// checking would pass no matter what the constant said.
+///
+/// The dash is U+2014.
+const NOT_SIGNED_IN: &str = "not signed in — run: llm-stream --login";
+
+/// Runs the CLI against an empty, throwaway config directory, so there are no
+/// credentials to find. Returns `(exit_ok, stdout, stderr)`.
+fn run_without_credentials(args: &[&str]) -> (bool, String, String) {
+    let dir = match tempfile::tempdir() {
+        Ok(dir) => dir,
+        Err(e) => panic!("could not create a temporary config directory: {e}"),
+    };
+    let mut command = Command::new(env!("CARGO_BIN_EXE_llm-stream"));
+    command.arg("--config-dir").arg(dir.path());
+    command.args(args);
+    // Without this the child inherits the harness's stdin, and `parse_args`
+    // reads stdin whenever it is not a terminal — the test would hang.
+    let output = match command.stdin(Stdio::null()).output() {
+        Ok(output) => output,
+        Err(e) => panic!("could not run the llm-stream binary: {e}"),
+    };
+    (
+        output.status.success(),
+        String::from_utf8_lossy(&output.stdout).into_owned(),
+        String::from_utf8_lossy(&output.stderr).into_owned(),
+    )
+}
+
+#[test]
+fn a_prompt_without_credentials_names_the_login_command() {
+    let (ok, stdout, stderr) = run_without_credentials(&["--api", "chatgpt", "hi"]);
+    assert!(
+        !ok,
+        "expected a failure exit\nstdout: {stdout}\nstderr: {stderr}"
+    );
+    assert!(stderr.contains(NOT_SIGNED_IN), "stderr: {stderr}");
+    // A caller piping stdout must get an empty pipe, not half an error.
+    assert!(stdout.is_empty(), "nothing should reach stdout: {stdout}");
+}
+
+#[test]
+fn models_without_credentials_names_the_login_command() {
+    let (ok, stdout, stderr) = run_without_credentials(&["--models"]);
+    assert!(
+        !ok,
+        "expected a failure exit\nstdout: {stdout}\nstderr: {stderr}"
+    );
+    assert!(stderr.contains(NOT_SIGNED_IN), "stderr: {stderr}");
+    // The quota warning must come after the credential check. Warning someone
+    // about a cost they were never going to pay is noise that trains them to
+    // ignore the warning when it matters.
+    assert!(
+        !stderr.contains("quota"),
+        "no quota warning before the guard: {stderr}"
+    );
+    assert!(stdout.is_empty(), "nothing should reach stdout: {stdout}");
+}