chrome-agent 0.16.0

//! Every CDP call has a deadline, so no in-page promise can wedge the tool forever.

use std::process::{Command, Stdio};
use std::time::{Duration, Instant};

mod common;
use common::TestBrowser;

/// Generous enough that a real answer always beats it, short enough that a hang is caught.
const HANG_LIMIT: Duration = Duration::from_secs(45);

fn run_cli(args: &[&str]) -> (String, i32) {
    let output = Command::new(common::binary())
        .args(args)
        .output()
        .expect("Failed to run chrome-agent");
    (
        String::from_utf8_lossy(&output.stdout).to_string(),
        output.status.code().unwrap_or(-1),
    )
}

/// Run and fail the test rather than the suite if the command hangs.
fn run_bounded(args: &[&str]) -> (String, i32, Duration) {
    let started = Instant::now();
    let mut child = Command::new(common::binary())
        .args(args)
        .stdout(Stdio::piped())
        .stderr(Stdio::null())
        .spawn()
        .expect("spawn chrome-agent");
    loop {
        if let Some(status) = child.try_wait().expect("poll chrome-agent") {
            let output = child.wait_with_output().expect("collect output");
            return (
                String::from_utf8_lossy(&output.stdout).to_string(),
                status.code().unwrap_or(-1),
                started.elapsed(),
            );
        }
        if started.elapsed() > HANG_LIMIT {
            let _ = child.kill();
            let _ = child.wait();
            panic!("command hung for more than {HANG_LIMIT:?}: {args:?}");
        }
        std::thread::sleep(Duration::from_millis(50));
    }
}

fn open(browser: &str, fixture: &str) -> bool {
    if !common::browser_ready() {
        return false;
    }
    let url = common::fixture_url(fixture);
    let (_, code) = run_cli(&["--browser", browser, "goto", &url]);
    if code != 0 {
        return common::unavailable(&format!("goto {fixture} failed"));
    }
    true
}

/// `eval` on a promise that never resolves errors instead of hanging.
#[test]
fn a_promise_that_never_resolves_becomes_an_error_not_a_hang() {
    let b = TestBrowser::new("cdp-timeout-eval");
    if !open(b.name(), "verdict_states.html") {
        return;
    }
    let (stdout, code, elapsed) = run_bounded(&[
        "--browser",
        b.name(),
        "--timeout",
        "5",
        "--json",
        "eval",
        "new Promise(() => {})",
    ]);
    assert_ne!(
        code, 0,
        "a command that never got an answer is not a success: {stdout}"
    );
    assert!(
        stdout.contains("timed out") || stdout.contains("timeout"),
        "the error must say what happened: {stdout}"
    );
    assert!(
        elapsed < Duration::from_secs(30),
        "the deadline should be the one asked for, not a multiple: {elapsed:?}"
    );
}

#[test]
fn the_deadline_is_the_one_the_caller_asked_for() {
    let b = TestBrowser::new("cdp-timeout-short");
    if !open(b.name(), "verdict_states.html") {
        return;
    }
    let (_, _, elapsed) = run_bounded(&[
        "--browser",
        b.name(),
        "--timeout",
        "3",
        "--json",
        "eval",
        "new Promise(() => {})",
    ]);
    assert!(
        elapsed >= Duration::from_secs(3),
        "it must actually wait the deadline: {elapsed:?}"
    );
    assert!(
        elapsed < Duration::from_secs(20),
        "and not much beyond it: {elapsed:?}"
    );
}

/// `inspect --limit` returns on a page whose mutations never stop: its settle debounce has
/// a hard ceiling.
#[test]
fn inspect_limit_returns_on_a_page_that_never_stops_mutating() {
    let b = TestBrowser::new("cdp-timeout-ticker");
    if !open(b.name(), "goto_ticker.html") {
        return;
    }
    // The limit must exceed what the page holds, or the collector returns before it reaches
    // the scroll probe and the test proves nothing.
    let (stdout, code, _) = run_bounded(&[
        "--browser",
        b.name(),
        "--timeout",
        "10",
        "--json",
        "inspect",
        "--limit",
        "500",
    ]);
    assert_eq!(code, 0, "the page is alive, not broken: {stdout}");
    assert!(stdout.contains("snapshot"), "{stdout}");
}

#[test]
fn a_normal_command_is_unaffected() {
    let b = TestBrowser::new("cdp-timeout-normal");
    if !open(b.name(), "verdict_states.html") {
        return;
    }
    let (stdout, code, elapsed) = run_bounded(&[
        "--browser",
        b.name(),
        "--timeout",
        "5",
        "--json",
        "eval",
        "1 + 1",
    ]);
    assert_eq!(code, 0, "{stdout}");
    assert!(stdout.contains("\"result\":2"), "{stdout}");
    assert!(
        elapsed < Duration::from_secs(5),
        "no deadline was reached: {elapsed:?}"
    );
}