car-server-core 0.50.0

//! The stack budget these tests run on, asserted directly.
//!
//! `handler.rs` is one `async fn` dispatcher over 382 string-literal method
//! arms (the `match` at `handler.rs:1809`). In a debug build the future that
//! produces is megabytes wide, and every test in this crate that sends a
//! JSON-RPC request holds it on the stack of the thread libtest gave that
//! test. Rust's default for a spawned thread is 2 MiB, which this crate's
//! tests were already running just under: Parslee-ai/car runs 32769625795 and
//! 32774744912 each aborted an ARBITRARY — and different — test with
//! `fatal runtime error: stack overflow`, surfacing only as
//! `Process completed with exit code 100`, and the 2026-08-25 nightly's
//! `coverage` job went the same way.
//!
//! `RUST_MIN_STACK` in the repo-root `.cargo/config.toml` raises it to 8 MiB
//! for every entry point that runs these tests. Nothing else fails if that
//! line is deleted — not until some future change grows the dispatcher and an
//! unrelated test aborts, months later, wearing the same unattributable
//! costume. This test is what fails instead, immediately and by name.
//!
//! It asserts the PROPERTY (a test thread here has room to spare), not the
//! mechanism, so raising the budget a different way keeps it green.

/// 3 MiB live on the stack: comfortably inside 8 MiB, impossible in Rust's
/// 2 MiB default. Same shape as the dispatcher future — one large frame held
/// across the body of the test.
#[test]
fn a_test_thread_here_has_more_than_the_default_two_mib_of_stack() {
    let buf = [7u8; 3 * 1024 * 1024];
    assert_eq!(
        std::hint::black_box(&buf)[3 * 1024 * 1024 - 1],
        7,
        "if this aborted instead of failing, the stack budget is gone: see \
         docs/solutions/nextest-exit-100-is-a-stack-overflow.md"
    );
}