//! Baseline pin (Embedding-ABI M1, spec Testing-strategy item 0):
//! `ail build` (default executable mode) on a `main`-free module
//! surfaces `CodegenError::MissingEntryMain` at the CLI build-path
//! layer. The staticlib emit-mode (Task 5/6) is *defined* as
//! suppressing exactly this rejection; this pin guards the baseline
//! at the layer the suppression branches on. The codegen-unit layer
//! is independently pinned by
//! `crates/ailang-codegen/src/lib.rs` `missing_entry_main_is_error`.
//!
//! Pure reader: writes nothing to the repo.

use ailang_test_support::workspace_root;
use std::process::Command;

fn ail_bin() -> &'static str {
    env!("CARGO_BIN_EXE_ail")
}

#[test]
fn ail_build_on_main_free_module_is_rejected_at_cli() {
    let fixture = workspace_root()
        .join("examples")
        .join("embed_noentry_baseline.ail");
    assert!(fixture.exists(), "missing fixture {fixture:?}");

    let out_bin = std::env::temp_dir().join(format!(
        "ailang-embed-baseline-{}", std::process::id()
    ));
    let output = Command::new(ail_bin())
        .args([
            "build",
            fixture.to_str().unwrap(),
            "-o",
            out_bin.to_str().unwrap(),
        ])
        .output()
        .expect("run `ail build`");

    assert!(
        !output.status.success(),
        "ail build of a main-free module unexpectedly succeeded; \
         stdout={} stderr={}",
        String::from_utf8_lossy(&output.stdout),
        String::from_utf8_lossy(&output.stderr),
    );
    let stderr = String::from_utf8_lossy(&output.stderr);
    assert!(
        stderr.contains("has no `main` def"),
        "expected the MissingEntryMain message \
         (`entry module ... has no `main` def`); got stderr: {stderr}",
    );
    assert!(
        !out_bin.exists(),
        "no binary should be produced for a main-free module",
    );
}