denoland-deno/cli/tests/watcher_tests.rs

// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.

use flaky_test::flaky_test;
use std::fs::write;
use std::io::BufRead;
use test_util as util;
use test_util::assert_contains;
use test_util::TempDir;

mod watcher {
  use super::*;

  const CLEAR_SCREEN: &str = r#"[2J"#;

  // Helper function to skip watcher output that contains "Restarting"
  // phrase.
  fn skip_restarting_line(
    stderr_lines: &mut impl Iterator<Item = String>,
  ) -> String {
    loop {
      let msg = stderr_lines.next().unwrap();
      if !msg.contains("Restarting") {
        return msg;
      }
    }
  }

  fn read_all_lints(stderr_lines: &mut impl Iterator<Item = String>) -> String {
    let mut str = String::new();
    for t in stderr_lines {
      let t = util::strip_ansi_codes(&t);
      if t.starts_with("Watcher File change detected") {
        continue;
      }
      if t.starts_with("Watcher") {
        break;
      }
      if t.starts_with('(') {
        str.push_str(&t);
        str.push('\n');
      }
    }
    str
  }

  fn wait_for(
    condition: impl Fn(&str) -> bool,
    lines: &mut impl Iterator<Item = String>,
  ) {
    loop {
      let msg = lines.next().unwrap();
      if condition(&msg) {
        break;
      }
    }
  }

  fn wait_contains(s: &str, lines: &mut impl Iterator<Item = String>) {
    wait_for(|msg| msg.contains(s), lines)
  }

  fn read_line(s: &str, lines: &mut impl Iterator<Item = String>) -> String {
    lines.find(|m| m.contains(s)).unwrap()
  }

  fn check_alive_then_kill(mut child: std::process::Child) {
    assert!(child.try_wait().unwrap().is_none());
    child.kill().unwrap();
  }

  fn child_lines(
    child: &mut std::process::Child,
  ) -> (impl Iterator<Item = String>, impl Iterator<Item = String>) {
    let stdout_lines = std::io::BufReader::new(child.stdout.take().unwrap())
      .lines()
      .map(|r| {
        let line = r.unwrap();
        eprintln!("STDOUT: {}", line);
        line
      });
    let stderr_lines = std::io::BufReader::new(child.stderr.take().unwrap())
      .lines()
      .map(|r| {
        let line = r.unwrap();
        eprintln!("STERR: {}", line);
        line
      });
    (stdout_lines, stderr_lines)
  }

  #[test]
  fn lint_watch_test() {
    let t = TempDir::new();
    let badly_linted_original =
      util::testdata_path().join("lint/watch/badly_linted.js");
    let badly_linted_output =
      util::testdata_path().join("lint/watch/badly_linted.js.out");
    let badly_linted_fixed1 =
      util::testdata_path().join("lint/watch/badly_linted_fixed1.js");
    let badly_linted_fixed1_output =
      util::testdata_path().join("lint/watch/badly_linted_fixed1.js.out");
    let badly_linted_fixed2 =
      util::testdata_path().join("lint/watch/badly_linted_fixed2.js");
    let badly_linted_fixed2_output =
      util::testdata_path().join("lint/watch/badly_linted_fixed2.js.out");
    let badly_linted = t.path().join("badly_linted.js");

    std::fs::copy(badly_linted_original, &badly_linted).unwrap();

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("lint")
      .arg(&badly_linted)
      .arg("--watch")
      .arg("--unstable")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (_stdout_lines, mut stderr_lines) = child_lines(&mut child);
    let next_line = stderr_lines.next().unwrap();
    assert_contains!(&next_line, "Lint started");
    let mut output = read_all_lints(&mut stderr_lines);
    let expected = std::fs::read_to_string(badly_linted_output).unwrap();
    assert_eq!(output, expected);

    // Change content of the file again to be badly-linted1
    std::fs::copy(badly_linted_fixed1, &badly_linted).unwrap();
    std::thread::sleep(std::time::Duration::from_secs(1));

    output = read_all_lints(&mut stderr_lines);
    let expected = std::fs::read_to_string(badly_linted_fixed1_output).unwrap();
    assert_eq!(output, expected);

    // Change content of the file again to be badly-linted1
    std::fs::copy(badly_linted_fixed2, &badly_linted).unwrap();

    output = read_all_lints(&mut stderr_lines);
    let expected = std::fs::read_to_string(badly_linted_fixed2_output).unwrap();
    assert_eq!(output, expected);

    // the watcher process is still alive
    assert!(child.try_wait().unwrap().is_none());

    child.kill().unwrap();
    drop(t);
  }

  #[test]
  fn lint_watch_without_args_test() {
    let t = TempDir::new();
    let badly_linted_original =
      util::testdata_path().join("lint/watch/badly_linted.js");
    let badly_linted_output =
      util::testdata_path().join("lint/watch/badly_linted.js.out");
    let badly_linted_fixed1 =
      util::testdata_path().join("lint/watch/badly_linted_fixed1.js");
    let badly_linted_fixed1_output =
      util::testdata_path().join("lint/watch/badly_linted_fixed1.js.out");
    let badly_linted_fixed2 =
      util::testdata_path().join("lint/watch/badly_linted_fixed2.js");
    let badly_linted_fixed2_output =
      util::testdata_path().join("lint/watch/badly_linted_fixed2.js.out");
    let badly_linted = t.path().join("badly_linted.js");

    std::fs::copy(badly_linted_original, &badly_linted).unwrap();

    let mut child = util::deno_cmd()
      .current_dir(t.path())
      .arg("lint")
      .arg("--watch")
      .arg("--unstable")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (_stdout_lines, mut stderr_lines) = child_lines(&mut child);

    let next_line = stderr_lines.next().unwrap();
    assert_contains!(&next_line, "Lint started");
    let mut output = read_all_lints(&mut stderr_lines);
    let expected = std::fs::read_to_string(badly_linted_output).unwrap();
    assert_eq!(output, expected);

    // Change content of the file again to be badly-linted1
    std::fs::copy(badly_linted_fixed1, &badly_linted).unwrap();

    output = read_all_lints(&mut stderr_lines);
    let expected = std::fs::read_to_string(badly_linted_fixed1_output).unwrap();
    assert_eq!(output, expected);

    // Change content of the file again to be badly-linted1
    std::fs::copy(badly_linted_fixed2, &badly_linted).unwrap();
    std::thread::sleep(std::time::Duration::from_secs(1));

    output = read_all_lints(&mut stderr_lines);
    let expected = std::fs::read_to_string(badly_linted_fixed2_output).unwrap();
    assert_eq!(output, expected);

    // the watcher process is still alive
    assert!(child.try_wait().unwrap().is_none());

    child.kill().unwrap();
    drop(t);
  }

  #[test]
  fn lint_all_files_on_each_change_test() {
    let t = TempDir::new();
    let badly_linted_fixed0 =
      util::testdata_path().join("lint/watch/badly_linted.js");
    let badly_linted_fixed1 =
      util::testdata_path().join("lint/watch/badly_linted_fixed1.js");
    let badly_linted_fixed2 =
      util::testdata_path().join("lint/watch/badly_linted_fixed2.js");

    let badly_linted_1 = t.path().join("badly_linted_1.js");
    let badly_linted_2 = t.path().join("badly_linted_2.js");
    std::fs::copy(badly_linted_fixed0, badly_linted_1).unwrap();
    std::fs::copy(badly_linted_fixed1, &badly_linted_2).unwrap();

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("lint")
      .arg(t.path())
      .arg("--watch")
      .arg("--unstable")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (_stdout_lines, mut stderr_lines) = child_lines(&mut child);

    assert_contains!(
      read_line("Checked", &mut stderr_lines),
      "Checked 2 files"
    );

    std::fs::copy(badly_linted_fixed2, badly_linted_2).unwrap();

    assert_contains!(
      read_line("Checked", &mut stderr_lines),
      "Checked 2 files"
    );

    assert!(child.try_wait().unwrap().is_none());

    child.kill().unwrap();
    drop(t);
  }

  #[test]
  fn fmt_watch_test() {
    let fmt_testdata_path = util::testdata_path().join("fmt");
    let t = TempDir::new();
    let fixed = fmt_testdata_path.join("badly_formatted_fixed.js");
    let badly_formatted_original =
      fmt_testdata_path.join("badly_formatted.mjs");
    let badly_formatted = t.path().join("badly_formatted.js");
    std::fs::copy(&badly_formatted_original, &badly_formatted).unwrap();

    let mut child = util::deno_cmd()
      .current_dir(&fmt_testdata_path)
      .arg("fmt")
      .arg(&badly_formatted)
      .arg("--watch")
      .arg("--unstable")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (_stdout_lines, mut stderr_lines) = child_lines(&mut child);

    let next_line = stderr_lines.next().unwrap();
    assert_contains!(&next_line, "Fmt started");
    assert_contains!(
      skip_restarting_line(&mut stderr_lines),
      "badly_formatted.js"
    );
    assert_contains!(read_line("Checked", &mut stderr_lines), "Checked 1 file");

    let expected = std::fs::read_to_string(fixed.clone()).unwrap();
    let actual = std::fs::read_to_string(badly_formatted.clone()).unwrap();
    assert_eq!(actual, expected);

    // Change content of the file again to be badly formatted
    std::fs::copy(&badly_formatted_original, &badly_formatted).unwrap();

    assert_contains!(
      skip_restarting_line(&mut stderr_lines),
      "badly_formatted.js"
    );
    assert_contains!(read_line("Checked", &mut stderr_lines), "Checked 1 file");

    // Check if file has been automatically formatted by watcher
    let expected = std::fs::read_to_string(fixed).unwrap();
    let actual = std::fs::read_to_string(badly_formatted).unwrap();
    assert_eq!(actual, expected);
    check_alive_then_kill(child);
  }

  #[test]
  fn fmt_watch_without_args_test() {
    let fmt_testdata_path = util::testdata_path().join("fmt");
    let t = TempDir::new();
    let fixed = fmt_testdata_path.join("badly_formatted_fixed.js");
    let badly_formatted_original =
      fmt_testdata_path.join("badly_formatted.mjs");
    let badly_formatted = t.path().join("badly_formatted.js");
    std::fs::copy(&badly_formatted_original, &badly_formatted).unwrap();

    let mut child = util::deno_cmd()
      .current_dir(t.path())
      .arg("fmt")
      .arg("--watch")
      .arg("--unstable")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (_stdout_lines, mut stderr_lines) = child_lines(&mut child);

    let next_line = stderr_lines.next().unwrap();
    assert_contains!(&next_line, "Fmt started");
    assert_contains!(
      skip_restarting_line(&mut stderr_lines),
      "badly_formatted.js"
    );
    assert_contains!(read_line("Checked", &mut stderr_lines), "Checked 1 file");

    let expected = std::fs::read_to_string(fixed.clone()).unwrap();
    let actual = std::fs::read_to_string(badly_formatted.clone()).unwrap();
    assert_eq!(actual, expected);

    // Change content of the file again to be badly formatted
    std::fs::copy(&badly_formatted_original, &badly_formatted).unwrap();
    assert_contains!(
      skip_restarting_line(&mut stderr_lines),
      "badly_formatted.js"
    );
    assert_contains!(read_line("Checked", &mut stderr_lines), "Checked 1 file");

    // Check if file has been automatically formatted by watcher
    let expected = std::fs::read_to_string(fixed).unwrap();
    let actual = std::fs::read_to_string(badly_formatted).unwrap();
    assert_eq!(actual, expected);
    check_alive_then_kill(child);
  }

  #[test]
  fn fmt_check_all_files_on_each_change_test() {
    let t = TempDir::new();
    let fmt_testdata_path = util::testdata_path().join("fmt");
    let badly_formatted_original =
      fmt_testdata_path.join("badly_formatted.mjs");
    let badly_formatted_1 = t.path().join("badly_formatted_1.js");
    let badly_formatted_2 = t.path().join("badly_formatted_2.js");
    std::fs::copy(&badly_formatted_original, &badly_formatted_1).unwrap();
    std::fs::copy(&badly_formatted_original, badly_formatted_2).unwrap();

    let mut child = util::deno_cmd()
      .current_dir(&fmt_testdata_path)
      .arg("fmt")
      .arg(t.path())
      .arg("--watch")
      .arg("--check")
      .arg("--unstable")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (_stdout_lines, mut stderr_lines) = child_lines(&mut child);

    assert_contains!(
      read_line("error", &mut stderr_lines),
      "Found 2 not formatted files in 2 files"
    );

    // Change content of the file again to be badly formatted
    std::fs::copy(&badly_formatted_original, &badly_formatted_1).unwrap();

    assert_contains!(
      read_line("error", &mut stderr_lines),
      "Found 2 not formatted files in 2 files"
    );

    check_alive_then_kill(child);
  }

  #[test]
  fn bundle_js_watch() {
    use std::path::PathBuf;
    // Test strategy extends this of test bundle_js by adding watcher
    let t = TempDir::new();
    let file_to_watch = t.path().join("file_to_watch.ts");
    write(&file_to_watch, "console.log('Hello world');").unwrap();
    assert!(file_to_watch.is_file());
    let t = TempDir::new();
    let bundle = t.path().join("mod6.bundle.js");
    let mut deno = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("bundle")
      .arg(&file_to_watch)
      .arg(&bundle)
      .arg("--watch")
      .arg("--unstable")
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();

    let (_stdout_lines, mut stderr_lines) = child_lines(&mut deno);

    assert_contains!(stderr_lines.next().unwrap(), "Check");
    let next_line = stderr_lines.next().unwrap();
    assert_contains!(&next_line, "Bundle started");
    assert_contains!(stderr_lines.next().unwrap(), "file_to_watch.ts");
    assert_contains!(stderr_lines.next().unwrap(), "mod6.bundle.js");
    let file = PathBuf::from(&bundle);
    assert!(file.is_file());
    wait_contains("Bundle finished", &mut stderr_lines);

    write(&file_to_watch, "console.log('Hello world2');").unwrap();

    assert_contains!(stderr_lines.next().unwrap(), "Check");
    let next_line = stderr_lines.next().unwrap();
    assert_contains!(&next_line, CLEAR_SCREEN);
    assert_contains!(&next_line, "File change detected!");
    assert_contains!(stderr_lines.next().unwrap(), "file_to_watch.ts");
    assert_contains!(stderr_lines.next().unwrap(), "mod6.bundle.js");
    let file = PathBuf::from(&bundle);
    assert!(file.is_file());
    wait_contains("Bundle finished", &mut stderr_lines);

    // Confirm that the watcher keeps on working even if the file is updated and has invalid syntax
    write(&file_to_watch, "syntax error ^^").unwrap();

    assert_contains!(stderr_lines.next().unwrap(), "File change detected!");
    assert_contains!(stderr_lines.next().unwrap(), "error: ");
    wait_contains("Bundle failed", &mut stderr_lines);
    check_alive_then_kill(deno);
  }

  /// Confirm that the watcher continues to work even if module resolution fails at the *first* attempt
  #[test]
  fn bundle_watch_not_exit() {
    let t = TempDir::new();
    let file_to_watch = t.path().join("file_to_watch.ts");
    write(&file_to_watch, "syntax error ^^").unwrap();
    let target_file = t.path().join("target.js");

    let mut deno = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("bundle")
      .arg(&file_to_watch)
      .arg(&target_file)
      .arg("--watch")
      .arg("--unstable")
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (_stdout_lines, mut stderr_lines) = child_lines(&mut deno);

    let next_line = stderr_lines.next().unwrap();
    assert_contains!(&next_line, "Bundle started");
    assert_contains!(stderr_lines.next().unwrap(), "error:");
    assert_contains!(stderr_lines.next().unwrap(), "Bundle failed");
    // the target file hasn't been created yet
    assert!(!target_file.is_file());

    // Make sure the watcher actually restarts and works fine with the proper syntax
    write(&file_to_watch, "console.log(42);").unwrap();

    assert_contains!(stderr_lines.next().unwrap(), "Check");
    let next_line = stderr_lines.next().unwrap();
    assert_contains!(&next_line, CLEAR_SCREEN);
    assert_contains!(&next_line, "File change detected!");
    assert_contains!(stderr_lines.next().unwrap(), "file_to_watch.ts");
    assert_contains!(stderr_lines.next().unwrap(), "target.js");

    wait_contains("Bundle finished", &mut stderr_lines);

    // bundled file is created
    assert!(target_file.is_file());
    check_alive_then_kill(deno);
  }

  #[test]
  fn run_watch_no_dynamic() {
    let t = TempDir::new();
    let file_to_watch = t.path().join("file_to_watch.js");
    write(&file_to_watch, "console.log('Hello world');").unwrap();

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("run")
      .arg("--watch")
      .arg("--unstable")
      .arg("-L")
      .arg("debug")
      .arg(&file_to_watch)
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);

    wait_contains("Hello world", &mut stdout_lines);
    wait_for(
      |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
      &mut stderr_lines,
    );

    // Change content of the file
    write(&file_to_watch, "console.log('Hello world2');").unwrap();

    wait_contains("Restarting", &mut stderr_lines);
    wait_contains("Hello world2", &mut stdout_lines);
    wait_for(
      |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
      &mut stderr_lines,
    );

    // Add dependency
    let another_file = t.path().join("another_file.js");
    write(&another_file, "export const foo = 0;").unwrap();
    write(
      &file_to_watch,
      "import { foo } from './another_file.js'; console.log(foo);",
    )
    .unwrap();

    wait_contains("Restarting", &mut stderr_lines);
    wait_contains("0", &mut stdout_lines);
    wait_for(
      |m| m.contains("Watching paths") && m.contains("another_file.js"),
      &mut stderr_lines,
    );

    // Confirm that restarting occurs when a new file is updated
    write(&another_file, "export const foo = 42;").unwrap();

    wait_contains("Restarting", &mut stderr_lines);
    wait_contains("42", &mut stdout_lines);
    wait_for(
      |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
      &mut stderr_lines,
    );

    // Confirm that the watcher keeps on working even if the file is updated and has invalid syntax
    write(&file_to_watch, "syntax error ^^").unwrap();

    wait_contains("Restarting", &mut stderr_lines);
    wait_contains("error:", &mut stderr_lines);
    wait_for(
      |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
      &mut stderr_lines,
    );

    // Then restore the file
    write(
      &file_to_watch,
      "import { foo } from './another_file.js'; console.log(foo);",
    )
    .unwrap();

    wait_contains("Restarting", &mut stderr_lines);
    wait_contains("42", &mut stdout_lines);
    wait_for(
      |m| m.contains("Watching paths") && m.contains("another_file.js"),
      &mut stderr_lines,
    );

    // Update the content of the imported file with invalid syntax
    write(&another_file, "syntax error ^^").unwrap();

    wait_contains("Restarting", &mut stderr_lines);
    wait_contains("error:", &mut stderr_lines);
    wait_for(
      |m| m.contains("Watching paths") && m.contains("another_file.js"),
      &mut stderr_lines,
    );

    // Modify the imported file and make sure that restarting occurs
    write(&another_file, "export const foo = 'modified!';").unwrap();

    wait_contains("Restarting", &mut stderr_lines);
    wait_contains("modified!", &mut stdout_lines);
    wait_contains("Watching paths", &mut stderr_lines);
    check_alive_then_kill(child);
  }

  // TODO(bartlomieju): this test became flaky on macOS runner; it is unclear
  // if that's because of a bug in code or the runner itself. We should reenable
  // it once we upgrade to XL runners for macOS.
  #[cfg(not(target_os = "macos"))]
  #[test]
  fn run_watch_external_watch_files() {
    let t = TempDir::new();
    let file_to_watch = t.path().join("file_to_watch.js");
    write(&file_to_watch, "console.log('Hello world');").unwrap();

    let external_file_to_watch = t.path().join("external_file_to_watch.txt");
    write(&external_file_to_watch, "Hello world").unwrap();

    let mut watch_arg = "--watch=".to_owned();
    let external_file_to_watch_str = external_file_to_watch
      .clone()
      .into_os_string()
      .into_string()
      .unwrap();
    watch_arg.push_str(&external_file_to_watch_str);

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("run")
      .arg(watch_arg)
      .arg("-L")
      .arg("debug")
      .arg("--unstable")
      .arg(&file_to_watch)
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);
    wait_contains("Process started", &mut stderr_lines);
    wait_contains("Hello world", &mut stdout_lines);
    wait_for(
      |m| {
        m.contains("Watching paths") && m.contains("external_file_to_watch.txt")
      },
      &mut stderr_lines,
    );

    // Change content of the external file
    write(&external_file_to_watch, "Hello world2").unwrap();

    wait_contains("Restarting", &mut stderr_lines);
    wait_contains("Process finished", &mut stderr_lines);
    check_alive_then_kill(child);
  }

  #[test]
  fn run_watch_load_unload_events() {
    let t = TempDir::new();
    let file_to_watch = t.path().join("file_to_watch.js");
    write(
      &file_to_watch,
      r#"
      setInterval(() => {}, 0);
      window.addEventListener("load", () => {
        console.log("load");
      });

      window.addEventListener("unload", () => {
        console.log("unload");
      });
    "#,
    )
    .unwrap();

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("run")
      .arg("--watch")
      .arg("--unstable")
      .arg("-L")
      .arg("debug")
      .arg(&file_to_watch)
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);

    // Wait for the first load event to fire
    wait_contains("load", &mut stdout_lines);
    wait_for(
      |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
      &mut stderr_lines,
    );

    // Change content of the file, this time without an interval to keep it alive.
    write(
      &file_to_watch,
      r#"
      window.addEventListener("load", () => {
        console.log("load");
      });

      window.addEventListener("unload", () => {
        console.log("unload");
      });
    "#,
    )
    .unwrap();

    // Wait for the restart
    wait_contains("Restarting", &mut stderr_lines);

    // Confirm that the unload event was dispatched from the first run
    wait_contains("unload", &mut stdout_lines);

    // Followed by the load event of the second run
    wait_contains("load", &mut stdout_lines);

    // Which is then unloaded as there is nothing keeping it alive.
    wait_contains("unload", &mut stdout_lines);
    check_alive_then_kill(child);
  }

  /// Confirm that the watcher continues to work even if module resolution fails at the *first* attempt
  #[test]
  fn run_watch_not_exit() {
    let t = TempDir::new();
    let file_to_watch = t.path().join("file_to_watch.js");
    write(&file_to_watch, "syntax error ^^").unwrap();

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("run")
      .arg("--watch")
      .arg("--unstable")
      .arg("-L")
      .arg("debug")
      .arg(&file_to_watch)
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);

    wait_contains("Process started", &mut stderr_lines);
    wait_contains("error:", &mut stderr_lines);
    wait_for(
      |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
      &mut stderr_lines,
    );

    // Make sure the watcher actually restarts and works fine with the proper syntax
    write(&file_to_watch, "console.log(42);").unwrap();

    wait_contains("Restarting", &mut stderr_lines);
    wait_contains("42", &mut stdout_lines);
    wait_contains("Process finished", &mut stderr_lines);
    check_alive_then_kill(child);
  }

  #[test]
  fn run_watch_with_import_map_and_relative_paths() {
    fn create_relative_tmp_file(
      directory: &TempDir,
      filename: &'static str,
      filecontent: &'static str,
    ) -> std::path::PathBuf {
      let absolute_path = directory.path().join(filename);
      write(&absolute_path, filecontent).unwrap();
      let relative_path = absolute_path
        .strip_prefix(util::testdata_path())
        .unwrap()
        .to_owned();
      assert!(relative_path.is_relative());
      relative_path
    }
    let temp_directory = TempDir::new_in(&util::testdata_path());
    let file_to_watch = create_relative_tmp_file(
      &temp_directory,
      "file_to_watch.js",
      "console.log('Hello world');",
    );
    let import_map_path = create_relative_tmp_file(
      &temp_directory,
      "import_map.json",
      "{\"imports\": {}}",
    );

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("run")
      .arg("--unstable")
      .arg("--watch")
      .arg("--import-map")
      .arg(&import_map_path)
      .arg(&file_to_watch)
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);
    let next_line = stderr_lines.next().unwrap();
    assert_contains!(&next_line, "Process started");
    assert_contains!(stderr_lines.next().unwrap(), "Process finished");
    assert_contains!(stdout_lines.next().unwrap(), "Hello world");

    check_alive_then_kill(child);
  }

  #[test]
  fn run_watch_error_messages() {
    let t = TempDir::new();
    let file_to_watch = t.path().join("file_to_watch.js");
    write(
      &file_to_watch,
      "throw SyntaxError(`outer`, {cause: TypeError(`inner`)})",
    )
    .unwrap();

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("run")
      .arg("--watch")
      .arg(&file_to_watch)
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (_, mut stderr_lines) = child_lines(&mut child);

    wait_contains("Process started", &mut stderr_lines);
    wait_contains("error: Uncaught SyntaxError: outer", &mut stderr_lines);
    wait_contains("Caused by: TypeError: inner", &mut stderr_lines);
    wait_contains("Process finished", &mut stderr_lines);

    check_alive_then_kill(child);
  }

  #[test]
  fn test_watch() {
    let t = TempDir::new();

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("test")
      .arg("--watch")
      .arg("--unstable")
      .arg("--no-check")
      .arg(t.path())
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);

    assert_eq!(stdout_lines.next().unwrap(), "");
    assert_contains!(stdout_lines.next().unwrap(), "0 passed | 0 failed");
    wait_contains("Test finished", &mut stderr_lines);

    let foo_file = t.path().join("foo.js");
    let bar_file = t.path().join("bar.js");
    let foo_test = t.path().join("foo_test.js");
    let bar_test = t.path().join("bar_test.js");
    write(&foo_file, "export default function foo() { 1 + 1 }").unwrap();
    write(&bar_file, "export default function bar() { 2 + 2 }").unwrap();
    write(
      &foo_test,
      "import foo from './foo.js'; Deno.test('foo', foo);",
    )
    .unwrap();
    write(
      bar_test,
      "import bar from './bar.js'; Deno.test('bar', bar);",
    )
    .unwrap();

    assert_eq!(stdout_lines.next().unwrap(), "");
    assert_contains!(stdout_lines.next().unwrap(), "running 1 test");
    assert_contains!(stdout_lines.next().unwrap(), "foo", "bar");
    assert_contains!(stdout_lines.next().unwrap(), "running 1 test");
    assert_contains!(stdout_lines.next().unwrap(), "foo", "bar");
    stdout_lines.next();
    stdout_lines.next();
    stdout_lines.next();
    wait_contains("Test finished", &mut stderr_lines);

    // Change content of the file
    write(
      &foo_test,
      "import foo from './foo.js'; Deno.test('foobar', foo);",
    )
    .unwrap();

    assert_contains!(stderr_lines.next().unwrap(), "Restarting");
    assert_contains!(stdout_lines.next().unwrap(), "running 1 test");
    assert_contains!(stdout_lines.next().unwrap(), "foobar");
    stdout_lines.next();
    stdout_lines.next();
    stdout_lines.next();
    wait_contains("Test finished", &mut stderr_lines);

    // Add test
    let another_test = t.path().join("new_test.js");
    write(&another_test, "Deno.test('another one', () => 3 + 3)").unwrap();
    assert_contains!(stderr_lines.next().unwrap(), "Restarting");
    assert_contains!(stdout_lines.next().unwrap(), "running 1 test");
    assert_contains!(stdout_lines.next().unwrap(), "another one");
    stdout_lines.next();
    stdout_lines.next();
    stdout_lines.next();
    wait_contains("Test finished", &mut stderr_lines);

    // Confirm that restarting occurs when a new file is updated
    write(&another_test, "Deno.test('another one', () => 3 + 3); Deno.test('another another one', () => 4 + 4)")
    .unwrap();
    assert_contains!(stderr_lines.next().unwrap(), "Restarting");
    assert_contains!(stdout_lines.next().unwrap(), "running 2 tests");
    assert_contains!(stdout_lines.next().unwrap(), "another one");
    assert_contains!(stdout_lines.next().unwrap(), "another another one");
    stdout_lines.next();
    stdout_lines.next();
    stdout_lines.next();
    wait_contains("Test finished", &mut stderr_lines);

    // Confirm that the watcher keeps on working even if the file is updated and has invalid syntax
    write(&another_test, "syntax error ^^").unwrap();
    assert_contains!(stderr_lines.next().unwrap(), "Restarting");
    assert_contains!(stderr_lines.next().unwrap(), "error:");
    assert_contains!(stderr_lines.next().unwrap(), "Test failed");

    // Then restore the file
    write(&another_test, "Deno.test('another one', () => 3 + 3)").unwrap();
    assert_contains!(stderr_lines.next().unwrap(), "Restarting");
    assert_contains!(stdout_lines.next().unwrap(), "running 1 test");
    assert_contains!(stdout_lines.next().unwrap(), "another one");
    stdout_lines.next();
    stdout_lines.next();
    stdout_lines.next();
    wait_contains("Test finished", &mut stderr_lines);

    // Confirm that the watcher keeps on working even if the file is updated and the test fails
    // This also confirms that it restarts when dependencies change
    write(
      &foo_file,
      "export default function foo() { throw new Error('Whoops!'); }",
    )
    .unwrap();
    assert_contains!(stderr_lines.next().unwrap(), "Restarting");
    assert_contains!(stdout_lines.next().unwrap(), "running 1 test");
    assert_contains!(stdout_lines.next().unwrap(), "FAILED");
    wait_for(|m| m.contains("FAILED"), &mut stdout_lines);
    stdout_lines.next();
    wait_contains("Test finished", &mut stderr_lines);

    // Then restore the file
    write(&foo_file, "export default function foo() { 1 + 1 }").unwrap();
    assert_contains!(stderr_lines.next().unwrap(), "Restarting");
    assert_contains!(stdout_lines.next().unwrap(), "running 1 test");
    assert_contains!(stdout_lines.next().unwrap(), "foo");
    stdout_lines.next();
    stdout_lines.next();
    stdout_lines.next();
    wait_contains("Test finished", &mut stderr_lines);

    // Test that circular dependencies work fine
    write(
      &foo_file,
      "import './bar.js'; export default function foo() { 1 + 1 }",
    )
    .unwrap();
    write(
      &bar_file,
      "import './foo.js'; export default function bar() { 2 + 2 }",
    )
    .unwrap();
    check_alive_then_kill(child);
  }

  #[flaky_test]
  fn test_watch_doc() {
    let t = TempDir::new();

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("test")
      .arg("--watch")
      .arg("--doc")
      .arg("--unstable")
      .arg(t.path())
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);

    assert_eq!(stdout_lines.next().unwrap(), "");
    assert_contains!(stdout_lines.next().unwrap(), "0 passed | 0 failed");
    wait_contains("Test finished", &mut stderr_lines);

    let foo_file = t.path().join("foo.ts");
    write(
      &foo_file,
      r#"
    export default function foo() {}
  "#,
    )
    .unwrap();

    write(
      &foo_file,
      r#"
    /**
     * ```ts
     * import foo from "./foo.ts";
     * ```
     */
    export default function foo() {}
  "#,
    )
    .unwrap();

    // We only need to scan for a Check file://.../foo.ts$3-6 line that
    // corresponds to the documentation block being type-checked.
    assert_contains!(skip_restarting_line(&mut stderr_lines), "foo.ts$3-6");
    check_alive_then_kill(child);
  }

  #[test]
  fn test_watch_module_graph_error_referrer() {
    let t = TempDir::new();
    let file_to_watch = t.path().join("file_to_watch.js");
    write(&file_to_watch, "import './nonexistent.js';").unwrap();
    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("run")
      .arg("--watch")
      .arg("--unstable")
      .arg(&file_to_watch)
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (_, mut stderr_lines) = child_lines(&mut child);
    let line1 = stderr_lines.next().unwrap();
    assert_contains!(&line1, "Process started");
    let line2 = stderr_lines.next().unwrap();
    assert_contains!(&line2, "error: Module not found");
    assert_contains!(&line2, "nonexistent.js");
    let line3 = stderr_lines.next().unwrap();
    assert_contains!(&line3, "    at ");
    assert_contains!(&line3, "file_to_watch.js");
    wait_contains("Process finished", &mut stderr_lines);
    check_alive_then_kill(child);
  }

  // Regression test for https://github.com/denoland/deno/issues/15428.
  #[test]
  fn test_watch_unload_handler_error_on_drop() {
    let t = TempDir::new();
    let file_to_watch = t.path().join("file_to_watch.js");
    write(
      &file_to_watch,
      r#"
    addEventListener("unload", () => {
      throw new Error("foo");
    });
    setTimeout(() => {
      throw new Error("bar");
    });
    "#,
    )
    .unwrap();
    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("run")
      .arg("--watch")
      .arg(&file_to_watch)
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (_, mut stderr_lines) = child_lines(&mut child);
    wait_contains("Process started", &mut stderr_lines);
    wait_contains("Uncaught Error: bar", &mut stderr_lines);
    wait_contains("Process finished", &mut stderr_lines);
    check_alive_then_kill(child);
  }

  #[test]
  fn run_watch_dynamic_imports() {
    let t = TempDir::new();
    let file_to_watch = t.path().join("file_to_watch.js");
    write(
      &file_to_watch,
      r#"
    console.log("Hopefully dynamic import will be watched...");
    await import("./imported.js");
    "#,
    )
    .unwrap();
    let file_to_watch2 = t.path().join("imported.js");
    write(
      file_to_watch2,
      r#"
    import "./imported2.js";
    console.log("I'm dynamically imported and I cause restarts!");
    "#,
    )
    .unwrap();
    let file_to_watch3 = t.path().join("imported2.js");
    write(
      &file_to_watch3,
      r#"
    console.log("I'm statically imported from the dynamic import");
    "#,
    )
    .unwrap();

    let mut child = util::deno_cmd()
      .current_dir(util::testdata_path())
      .arg("run")
      .arg("--watch")
      .arg("--unstable")
      .arg("--allow-read")
      .arg("-L")
      .arg("debug")
      .arg(&file_to_watch)
      .env("NO_COLOR", "1")
      .stdout(std::process::Stdio::piped())
      .stderr(std::process::Stdio::piped())
      .spawn()
      .unwrap();
    let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);

    assert_contains!(stderr_lines.next().unwrap(), "Process started");

    wait_contains(
      "Hopefully dynamic import will be watched...",
      &mut stdout_lines,
    );
    wait_contains(
      "I'm statically imported from the dynamic import",
      &mut stdout_lines,
    );
    wait_contains(
      "I'm dynamically imported and I cause restarts!",
      &mut stdout_lines,
    );

    wait_contains("finished", &mut stderr_lines);
    wait_for(
      |m| m.contains("Watching paths") && m.contains("imported2.js"),
      &mut stderr_lines,
    );

    write(
    &file_to_watch3,
    r#"
    console.log("I'm statically imported from the dynamic import and I've changed");
    "#,
  )
  .unwrap();

    wait_contains("Restarting", &mut stderr_lines);
    wait_contains(
      "Hopefully dynamic import will be watched...",
      &mut stdout_lines,
    );
    wait_contains(
      "I'm statically imported from the dynamic import and I've changed",
      &mut stdout_lines,
    );
    wait_contains(
      "I'm dynamically imported and I cause restarts!",
      &mut stdout_lines,
    );

    check_alive_then_kill(child);
  }
}