feat: "deno bench" subcommand (#13713)

This commit adds "deno bench" subcommand and "Deno.bench()"
API that allows to register bench cases. 

The API is modelled after "Deno.test()" and "deno test" subcommand.

Currently the output is rudimentary and bench cases and not
subject to "ops" and "resource" sanitizers.

Co-authored-by: evan <github@evan.lol>

Cargo.lock

@@ -119,6 +119,15 @@ version = "1.0.55"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "159bb86af3a200e19a068f4224eae4c8bb2d0fa054c7e5d1cacd5cef95e684cd"
 
+[[package]]
+name = "arrayvec"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cd9fd44efafa8690358b7408d253adf110036b88f55672a933f01d616ad9b1b9"
+dependencies = [
+ "nodrop",
+]
+
 [[package]]
 name = "arrayvec"
 version = "0.5.2"
@@ -775,6 +784,7 @@ dependencies = [
  "nix",
  "node_resolver",
  "notify",
+ "num-format",
  "once_cell",
  "os_pipe",
  "percent-encoding",
@@ -2506,6 +2516,12 @@ dependencies = [
  "serde_json",
 ]
 
+[[package]]
+name = "nodrop"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72ef4a56884ca558e5ddb05a1d1e7e1bfd9a68d9ed024c21704cc98872dae1bb"
+
 [[package]]
 name = "notify"
 version = "5.0.0-pre.12"
@@ -2563,6 +2579,16 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "num-format"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bafe4179722c2894288ee77a9f044f02811c86af699344c498b0840c698a2465"
+dependencies = [
+ "arrayvec 0.4.12",
+ "itoa 0.4.8",
+]
+
 [[package]]
 name = "num-integer"
 version = "0.1.44"

cli/Cargo.toml

@@ -77,6 +77,7 @@ log = { version = "=0.4.14", features = ["serde"] }
 lspower = "=1.4.0"
 node_resolver = "0.1.0"
 notify = "=5.0.0-pre.12"
+num-format = "=0.4.0"
 once_cell = "=1.9.0"
 percent-encoding = "=2.1.0"
 pin-project = "=1.0.8"

cli/dts/lib.deno.ns.d.ts

@@ -457,6 +457,7 @@ declare namespace Deno {
     options: Omit<TestDefinition, "fn" | "name">,
     fn: (t: TestContext) => void | Promise<void>,
   ): void;
+
   /** Exit the Deno process with optional exit code. If no exit code is supplied
    * then Deno will exit with return code of 0.
    *

cli/dts/lib.deno.unstable.d.ts

@@ -4,6 +4,180 @@
 /// <reference lib="deno.ns" />
 
 declare namespace Deno {
+  export interface BenchDefinition {
+    fn: () => void | Promise<void>;
+    name: string;
+    ignore?: boolean;
+    /** Specify number of iterations benchmark should perform. Defaults to 1000. */
+    n?: number;
+    /** Specify number of warmup iterations benchmark should perform. Defaults
+     * to 1000.
+     *
+     * These iterations are not measured. It allows the code to be optimized
+     * by JIT compiler before measuring its performance. */
+    warmup?: number;
+    /** If at least one bench has `only` set to true, only run benches that have
+     * `only` set to true and fail the bench suite. */
+    only?: boolean;
+    /** Ensure the bench case does not prematurely cause the process to exit,
+     * for example via a call to `Deno.exit`. Defaults to true. */
+    sanitizeExit?: boolean;
+
+    /** Specifies the permissions that should be used to run the bench.
+     * Set this to "inherit" to keep the calling thread's permissions.
+     * Set this to "none" to revoke all permissions.
+     *
+     * Defaults to "inherit".
+     */
+    permissions?: Deno.PermissionOptions;
+  }
+
+  /** Register a bench which will be run when `deno bench` is used on the command
+   * line and the containing module looks like a bench module.
+   * `fn` can be async if required.
+   * ```ts
+   * import {assert, fail, assertEquals} from "https://deno.land/std/testing/asserts.ts";
+   *
+   * Deno.bench({
+   *   name: "example test",
+   *   fn(): void {
+   *     assertEquals("world", "world");
+   *   },
+   * });
+   *
+   * Deno.bench({
+   *   name: "example ignored test",
+   *   ignore: Deno.build.os === "windows",
+   *   fn(): void {
+   *     // This test is ignored only on Windows machines
+   *   },
+   * });
+   *
+   * Deno.bench({
+   *   name: "example async test",
+   *   async fn() {
+   *     const decoder = new TextDecoder("utf-8");
+   *     const data = await Deno.readFile("hello_world.txt");
+   *     assertEquals(decoder.decode(data), "Hello world");
+   *   }
+   * });
+   * ```
+   */
+  export function bench(t: BenchDefinition): void;
+
+  /** Register a bench which will be run when `deno bench` is used on the command
+   * line and the containing module looks like a bench module.
+   * `fn` can be async if required.
+   *
+   * ```ts
+   * import {assert, fail, assertEquals} from "https://deno.land/std/testing/asserts.ts";
+   *
+   * Deno.bench("My test description", (): void => {
+   *   assertEquals("hello", "hello");
+   * });
+   *
+   * Deno.bench("My async test description", async (): Promise<void> => {
+   *   const decoder = new TextDecoder("utf-8");
+   *   const data = await Deno.readFile("hello_world.txt");
+   *   assertEquals(decoder.decode(data), "Hello world");
+   * });
+   * ```
+   */
+  export function bench(
+    name: string,
+    fn: () => void | Promise<void>,
+  ): void;
+
+  /** Register a bench which will be run when `deno bench` is used on the command
+   * line and the containing module looks like a bench module.
+   * `fn` can be async if required. Declared function must have a name.
+   *
+   * ```ts
+   * import {assert, fail, assertEquals} from "https://deno.land/std/testing/asserts.ts";
+   *
+   * Deno.bench(function myTestName(): void {
+   *   assertEquals("hello", "hello");
+   * });
+   *
+   * Deno.bench(async function myOtherTestName(): Promise<void> {
+   *   const decoder = new TextDecoder("utf-8");
+   *   const data = await Deno.readFile("hello_world.txt");
+   *   assertEquals(decoder.decode(data), "Hello world");
+   * });
+   * ```
+   */
+  export function bench(fn: () => void | Promise<void>): void;
+
+  /** Register a bench which will be run when `deno bench` is used on the command
+   * line and the containing module looks like a bench module.
+   * `fn` can be async if required.
+   *
+   * ```ts
+   * import {assert, fail, assertEquals} from "https://deno.land/std/testing/asserts.ts";
+   *
+   * Deno.bench("My test description", { permissions: { read: true } }, (): void => {
+   *   assertEquals("hello", "hello");
+   * });
+   *
+   * Deno.bench("My async test description", { permissions: { read: false } }, async (): Promise<void> => {
+   *   const decoder = new TextDecoder("utf-8");
+   *   const data = await Deno.readFile("hello_world.txt");
+   *   assertEquals(decoder.decode(data), "Hello world");
+   * });
+   * ```
+   */
+  export function bench(
+    name: string,
+    options: Omit<BenchDefinition, "fn" | "name">,
+    fn: () => void | Promise<void>,
+  ): void;
+
+  /** Register a bench which will be run when `deno bench` is used on the command
+   * line and the containing module looks like a bench module.
+   * `fn` can be async if required.
+   *
+   * ```ts
+   * import {assert, fail, assertEquals} from "https://deno.land/std/testing/asserts.ts";
+   *
+   * Deno.bench({ name: "My test description", permissions: { read: true } }, (): void => {
+   *   assertEquals("hello", "hello");
+   * });
+   *
+   * Deno.bench({ name: "My async test description", permissions: { read: false } }, async (): Promise<void> => {
+   *   const decoder = new TextDecoder("utf-8");
+   *   const data = await Deno.readFile("hello_world.txt");
+   *   assertEquals(decoder.decode(data), "Hello world");
+   * });
+   * ```
+   */
+  export function bench(
+    options: Omit<BenchDefinition, "fn">,
+    fn: () => void | Promise<void>,
+  ): void;
+
+  /** Register a bench which will be run when `deno bench` is used on the command
+   * line and the containing module looks like a bench module.
+   * `fn` can be async if required. Declared function must have a name.
+   *
+   * ```ts
+   * import {assert, fail, assertEquals} from "https://deno.land/std/testing/asserts.ts";
+   *
+   * Deno.bench({ permissions: { read: true } }, function myTestName(): void {
+   *   assertEquals("hello", "hello");
+   * });
+   *
+   * Deno.bench({ permissions: { read: false } }, async function myOtherTestName(): Promise<void> {
+   *   const decoder = new TextDecoder("utf-8");
+   *   const data = await Deno.readFile("hello_world.txt");
+   *   assertEquals(decoder.decode(data), "Hello world");
+   * });
+   * ```
+   */
+  export function bench(
+    options: Omit<BenchDefinition, "fn" | "name">,
+    fn: () => void | Promise<void>,
+  ): void;
+
   /**
    * **UNSTABLE**: New API, yet to be vetted.  This API is under consideration to
    * determine if permissions are required to call it.

cli/flags.rs

@@ -35,6 +35,13 @@ static LONG_VERSION: Lazy<String> = Lazy::new(|| {
   )
 });
 
+#[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
+pub struct BenchFlags {
+  pub ignore: Vec<PathBuf>,
+  pub include: Option<Vec<String>>,
+  pub filter: Option<String>,
+}
+
 #[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
 pub struct BundleFlags {
   pub source_file: String,
@@ -177,6 +184,7 @@ pub struct VendorFlags {
 
 #[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
 pub enum DenoSubcommand {
+  Bench(BenchFlags),
   Bundle(BundleFlags),
   Cache(CacheFlags),
   Compile(CompileFlags),
@@ -487,26 +495,27 @@ pub fn flags_from_vec(args: Vec<String>) -> clap::Result<Flags> {
   }
 
   match matches.subcommand() {
-    Some(("run", m)) => run_parse(&mut flags, m),
-    Some(("fmt", m)) => fmt_parse(&mut flags, m),
-    Some(("types", m)) => types_parse(&mut flags, m),
-    Some(("cache", m)) => cache_parse(&mut flags, m),
-    Some(("coverage", m)) => coverage_parse(&mut flags, m),
-    Some(("info", m)) => info_parse(&mut flags, m),
-    Some(("eval", m)) => eval_parse(&mut flags, m),
-    Some(("repl", m)) => repl_parse(&mut flags, m),
+    Some(("bench", m)) => bench_parse(&mut flags, m),
     Some(("bundle", m)) => bundle_parse(&mut flags, m),
-    Some(("install", m)) => install_parse(&mut flags, m),
-    Some(("uninstall", m)) => uninstall_parse(&mut flags, m),
-    Some(("completions", m)) => completions_parse(&mut flags, m, app),
-    Some(("test", m)) => test_parse(&mut flags, m),
-    Some(("upgrade", m)) => upgrade_parse(&mut flags, m),
-    Some(("doc", m)) => doc_parse(&mut flags, m),
-    Some(("lint", m)) => lint_parse(&mut flags, m),
+    Some(("cache", m)) => cache_parse(&mut flags, m),
     Some(("compile", m)) => compile_parse(&mut flags, m),
+    Some(("completions", m)) => completions_parse(&mut flags, m, app),
+    Some(("coverage", m)) => coverage_parse(&mut flags, m),
+    Some(("doc", m)) => doc_parse(&mut flags, m),
+    Some(("eval", m)) => eval_parse(&mut flags, m),
+    Some(("fmt", m)) => fmt_parse(&mut flags, m),
+    Some(("info", m)) => info_parse(&mut flags, m),
+    Some(("install", m)) => install_parse(&mut flags, m),
+    Some(("lint", m)) => lint_parse(&mut flags, m),
     Some(("lsp", m)) => lsp_parse(&mut flags, m),
-    Some(("vendor", m)) => vendor_parse(&mut flags, m),
+    Some(("repl", m)) => repl_parse(&mut flags, m),
+    Some(("run", m)) => run_parse(&mut flags, m),
     Some(("task", m)) => task_parse(&mut flags, m),
+    Some(("test", m)) => test_parse(&mut flags, m),
+    Some(("types", m)) => types_parse(&mut flags, m),
+    Some(("uninstall", m)) => uninstall_parse(&mut flags, m),
+    Some(("upgrade", m)) => upgrade_parse(&mut flags, m),
+    Some(("vendor", m)) => vendor_parse(&mut flags, m),
     _ => handle_repl_flags(&mut flags, ReplFlags { eval: None }),
   }
 
@@ -560,6 +569,7 @@ If the flag is set, restrict these messages to errors.",
         )
         .global(true),
     )
+    .subcommand(bench_subcommand())
     .subcommand(bundle_subcommand())
     .subcommand(cache_subcommand())
     .subcommand(compile_subcommand())
@@ -584,6 +594,50 @@ If the flag is set, restrict these messages to errors.",
     .after_help(ENV_VARIABLES_HELP)
 }
 
+fn bench_subcommand<'a>() -> App<'a> {
+  runtime_args(App::new("bench"), true, false)
+    .setting(AppSettings::TrailingVarArg)
+    .arg(
+      Arg::new("ignore")
+        .long("ignore")
+        .takes_value(true)
+        .use_delimiter(true)
+        .require_equals(true)
+        .help("Ignore files"),
+    )
+    .arg(
+      Arg::new("filter")
+        .setting(ArgSettings::AllowHyphenValues)
+        .long("filter")
+        .takes_value(true)
+        .help("Run benchmarks with this string or pattern in the bench name"),
+    )
+    .arg(
+      Arg::new("files")
+        .help("List of file names to run")
+        .takes_value(true)
+        .multiple_values(true)
+        .multiple_occurrences(true),
+    )
+    .arg(watch_arg(false))
+    .arg(no_clear_screen_arg())
+    .arg(script_arg().last(true))
+    .about("Run benchmarks")
+    .long_about(
+      "Run benchmarks using Deno's built-in bench tool.
+
+Evaluate the given modules, run all benches declared with 'Deno.bench()' and
+report results to standard output:
+
+  deno bench src/fetch_bench.ts src/signal_bench.ts
+
+Directory arguments are expanded to all contained files matching the glob
+{*_,*.,}bench.{js,mjs,ts,jsx,tsx}:
+
+  deno bench src/",
+    )
+}
+
 fn bundle_subcommand<'a>() -> App<'a> {
   compile_args(App::new("bundle"))
     .arg(Arg::new("source_file").takes_value(true).required(true))
@@ -1880,6 +1934,51 @@ fn unsafely_ignore_certificate_errors_arg<'a>() -> Arg<'a> {
     .validator(crate::flags_allow_net::validator)
 }
 
+fn bench_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
+  runtime_args_parse(flags, matches, true, false);
+
+  // NOTE: `deno bench` always uses `--no-prompt`, tests shouldn't ever do
+  // interactive prompts, unless done by user code
+  flags.no_prompt = true;
+
+  let ignore = match matches.values_of("ignore") {
+    Some(f) => f.map(PathBuf::from).collect(),
+    None => vec![],
+  };
+
+  let filter = matches.value_of("filter").map(String::from);
+
+  if matches.is_present("script_arg") {
+    let script_arg: Vec<String> = matches
+      .values_of("script_arg")
+      .unwrap()
+      .map(String::from)
+      .collect();
+
+    for v in script_arg {
+      flags.argv.push(v);
+    }
+  }
+
+  let include = if matches.is_present("files") {
+    let files: Vec<String> = matches
+      .values_of("files")
+      .unwrap()
+      .map(String::from)
+      .collect();
+    Some(files)
+  } else {
+    None
+  };
+
+  watch_arg_parse(flags, matches, false);
+  flags.subcommand = DenoSubcommand::Bench(BenchFlags {
+    include,
+    ignore,
+    filter,
+  });
+}
+
 fn bundle_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
   compile_args_parse(flags, matches);
 
@@ -5166,4 +5265,39 @@ mod tests {
       }
     );
   }
+
+  #[test]
+  fn bench_with_flags() {
+    let r = flags_from_vec(svec![
+      "deno",
+      "bench",
+      "--unstable",
+      "--filter",
+      "- foo",
+      "--location",
+      "https:foo",
+      "--allow-net",
+      "dir1/",
+      "dir2/",
+      "--",
+      "arg1",
+      "arg2"
+    ]);
+    assert_eq!(
+      r.unwrap(),
+      Flags {
+        subcommand: DenoSubcommand::Bench(BenchFlags {
+          filter: Some("- foo".to_string()),
+          include: Some(svec!["dir1/", "dir2/"]),
+          ignore: vec![],
+        }),
+        unstable: true,
+        location: Some(Url::parse("https://foo/").unwrap()),
+        allow_net: Some(vec![]),
+        no_prompt: true,
+        argv: svec!["arg1", "arg2"],
+        ..Flags::default()
+      }
+    );
+  }
 }

cli/fs_util.rs

@@ -152,6 +152,19 @@ pub fn is_supported_test_path(path: &Path) -> bool {
   }
 }
 
+/// Checks if the path has a basename and extension Deno supports for benches.
+pub fn is_supported_bench_path(path: &Path) -> bool {
+  if let Some(name) = path.file_stem() {
+    let basename = name.to_string_lossy();
+    (basename.ends_with("_bench")
+      || basename.ends_with(".bench")
+      || basename == "bench")
+      && is_supported_ext(path)
+  } else {
+    false
+  }
+}
+
 /// Checks if the path has an extension Deno supports for tests.
 pub fn is_supported_test_ext(path: &Path) -> bool {
   if let Some(ext) = get_extension(path) {

cli/main.rs

@@ -40,6 +40,7 @@ mod windows_util;
 
 use crate::file_fetcher::File;
 use crate::file_watcher::ResolutionResult;
+use crate::flags::BenchFlags;
 use crate::flags::BundleFlags;
 use crate::flags::CacheFlags;
 use crate::flags::CheckFlag;
@@ -1248,6 +1249,19 @@ async fn coverage_command(
   Ok(0)
 }
 
+async fn bench_command(
+  flags: Flags,
+  bench_flags: BenchFlags,
+) -> Result<i32, AnyError> {
+  if flags.watch.is_some() {
+    tools::bench::run_benchmarks_with_watch(flags, bench_flags).await?;
+  } else {
+    tools::bench::run_benchmarks(flags, bench_flags).await?;
+  }
+
+  Ok(0)
+}
+
 async fn test_command(
   flags: Flags,
   test_flags: TestFlags,
@@ -1328,6 +1342,9 @@ fn get_subcommand(
   flags: Flags,
 ) -> Pin<Box<dyn Future<Output = Result<i32, AnyError>>>> {
   match flags.subcommand.clone() {
+    DenoSubcommand::Bench(bench_flags) => {
+      bench_command(flags, bench_flags).boxed_local()
+    }
     DenoSubcommand::Bundle(bundle_flags) => {
       bundle_command(flags, bundle_flags).boxed_local()
     }

cli/ops/bench.rs

@@ -0,0 +1,99 @@
+use crate::tools::bench::BenchEvent;
+use deno_core::error::generic_error;
+use deno_core::error::AnyError;
+use deno_core::op_sync;
+use deno_core::Extension;
+use deno_core::ModuleSpecifier;
+use deno_core::OpState;
+use deno_runtime::permissions::create_child_permissions;
+use deno_runtime::permissions::ChildPermissionsArg;
+use deno_runtime::permissions::Permissions;
+use std::time;
+use tokio::sync::mpsc::UnboundedSender;
+use uuid::Uuid;
+
+pub fn init(sender: UnboundedSender<BenchEvent>) -> Extension {
+  Extension::builder()
+    .ops(vec![
+      (
+        "op_pledge_test_permissions",
+        op_sync(op_pledge_test_permissions),
+      ),
+      (
+        "op_restore_test_permissions",
+        op_sync(op_restore_test_permissions),
+      ),
+      ("op_get_bench_origin", op_sync(op_get_bench_origin)),
+      ("op_dispatch_bench_event", op_sync(op_dispatch_bench_event)),
+      ("op_bench_now", op_sync(op_bench_now)),
+    ])
+    .state(move |state| {
+      state.put(sender.clone());
+      Ok(())
+    })
+    .build()
+}
+
+#[derive(Clone)]
+struct PermissionsHolder(Uuid, Permissions);
+
+pub fn op_pledge_test_permissions(
+  state: &mut OpState,
+  args: ChildPermissionsArg,
+  _: (),
+) -> Result<Uuid, AnyError> {
+  let token = Uuid::new_v4();
+  let parent_permissions = state.borrow_mut::<Permissions>();
+  let worker_permissions = create_child_permissions(parent_permissions, args)?;
+  let parent_permissions = parent_permissions.clone();
+
+  state.put::<PermissionsHolder>(PermissionsHolder(token, parent_permissions));
+
+  // NOTE: This call overrides current permission set for the worker
+  state.put::<Permissions>(worker_permissions);
+
+  Ok(token)
+}
+
+pub fn op_restore_test_permissions(
+  state: &mut OpState,
+  token: Uuid,
+  _: (),
+) -> Result<(), AnyError> {
+  if let Some(permissions_holder) = state.try_take::<PermissionsHolder>() {
+    if token != permissions_holder.0 {
+      panic!("restore test permissions token does not match the stored token");
+    }
+
+    let permissions = permissions_holder.1;
+    state.put::<Permissions>(permissions);
+    Ok(())
+  } else {
+    Err(generic_error("no permissions to restore"))
+  }
+}
+
+fn op_get_bench_origin(
+  state: &mut OpState,
+  _: (),
+  _: (),
+) -> Result<String, AnyError> {
+  Ok(state.borrow::<ModuleSpecifier>().to_string())
+}
+
+fn op_dispatch_bench_event(
+  state: &mut OpState,
+  event: BenchEvent,
+  _: (),
+) -> Result<(), AnyError> {
+  let sender = state.borrow::<UnboundedSender<BenchEvent>>().clone();
+  sender.send(event).ok();
+
+  Ok(())
+}
+
+fn op_bench_now(state: &mut OpState, _: (), _: ()) -> Result<u64, AnyError> {
+  let ns = state.borrow::<time::Instant>().elapsed().as_nanos();
+  let ns_u64 = u64::try_from(ns)?;
+  Ok(ns_u64)
+}

cli/ops/mod.rs

@@ -3,6 +3,7 @@
 use crate::proc_state::ProcState;
 use deno_core::Extension;
 
+pub mod bench;
 mod errors;
 mod runtime_compiler;
 pub mod testing;

cli/tests/integration/bench_tests.rs

@@ -0,0 +1,135 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use crate::itest;
+
+itest!(overloads {
+  args: "bench --unstable bench/overloads.ts",
+  exit_code: 0,
+  output: "bench/overloads.out",
+});
+
+itest!(meta {
+  args: "bench --unstable bench/meta.ts",
+  exit_code: 0,
+  output: "bench/meta.out",
+});
+
+itest!(pass {
+  args: "bench --unstable bench/pass.ts",
+  exit_code: 0,
+  output: "bench/pass.out",
+});
+
+itest!(ignore {
+  args: "bench --unstable bench/ignore.ts",
+  exit_code: 0,
+  output: "bench/ignore.out",
+});
+
+itest!(ignore_permissions {
+  args: "bench --unstable bench/ignore_permissions.ts",
+  exit_code: 0,
+  output: "bench/ignore_permissions.out",
+});
+
+itest!(fail {
+  args: "bench --unstable bench/fail.ts",
+  exit_code: 1,
+  output: "bench/fail.out",
+});
+
+itest!(collect {
+  args: "bench --unstable --ignore=bench/collect/ignore bench/collect",
+  exit_code: 0,
+  output: "bench/collect.out",
+});
+
+itest!(load_unload {
+  args: "bench --unstable bench/load_unload.ts",
+  exit_code: 0,
+  output: "bench/load_unload.out",
+});
+
+itest!(interval {
+  args: "bench --unstable bench/interval.ts",
+  exit_code: 0,
+  output: "bench/interval.out",
+});
+
+itest!(quiet {
+  args: "bench --unstable --quiet bench/quiet.ts",
+  exit_code: 0,
+  output: "bench/quiet.out",
+});
+
+itest!(only {
+  args: "bench --unstable bench/only.ts",
+  exit_code: 1,
+  output: "bench/only.out",
+});
+
+itest!(no_check {
+  args: "bench --unstable --no-check bench/no_check.ts",
+  exit_code: 1,
+  output: "bench/no_check.out",
+});
+
+itest!(allow_all {
+  args: "bench  --unstable --allow-all bench/allow_all.ts",
+  exit_code: 0,
+  output: "bench/allow_all.out",
+});
+
+itest!(allow_none {
+  args: "bench --unstable bench/allow_none.ts",
+  exit_code: 1,
+  output: "bench/allow_none.out",
+});
+
+itest!(exit_sanitizer {
+  args: "bench --unstable bench/exit_sanitizer.ts",
+  output: "bench/exit_sanitizer.out",
+  exit_code: 1,
+});
+
+itest!(clear_timeout {
+  args: "bench --unstable bench/clear_timeout.ts",
+  exit_code: 0,
+  output: "bench/clear_timeout.out",
+});
+
+itest!(finally_timeout {
+  args: "bench --unstable bench/finally_timeout.ts",
+  exit_code: 1,
+  output: "bench/finally_timeout.out",
+});
+
+itest!(unresolved_promise {
+  args: "bench --unstable bench/unresolved_promise.ts",
+  exit_code: 1,
+  output: "bench/unresolved_promise.out",
+});
+
+itest!(unhandled_rejection {
+  args: "bench --unstable bench/unhandled_rejection.ts",
+  exit_code: 1,
+  output: "bench/unhandled_rejection.out",
+});
+
+itest!(filter {
+  args: "bench --unstable --filter=foo bench/filter",
+  exit_code: 0,
+  output: "bench/filter.out",
+});
+
+itest!(no_prompt_by_default {
+  args: "bench --unstable bench/no_prompt_by_default.ts",
+  exit_code: 1,
+  output: "bench/no_prompt_by_default.out",
+});
+
+itest!(no_prompt_with_denied_perms {
+  args: "bench --unstable --allow-read bench/no_prompt_with_denied_perms.ts",
+  exit_code: 1,
+  output: "bench/no_prompt_with_denied_perms.out",
+});

cli/tests/integration/mod.rs

@@ -50,6 +50,8 @@ macro_rules! itest_flaky(
 // the test (ex. `lint_tests.rs`) and which is the implementation (ex. `lint.rs`)
 // when both are open, especially for two tabs in VS Code
 
+#[path = "bench_tests.rs"]
+mod bench;
 #[path = "bundle_tests.rs"]
 mod bundle;
 #[path = "cache_tests.rs"]

cli/tests/testdata/bench/allow_all.out

@@ -0,0 +1,18 @@
+[WILDCARD]
+running 14 benches from [WILDCARD]
+bench read false ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench read true ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench write false ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench write true ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench net false ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench net true ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench env false ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench env true ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench run false ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench run true ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench ffi false ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench ffi true ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench hrtime false ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench hrtime true ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+
+bench result: ok. 14 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out [WILDCARD]

cli/tests/testdata/bench/allow_all.ts

@@ -0,0 +1,35 @@
+import { assertEquals } from "../../../../test_util/std/testing/asserts.ts";
+
+const permissions: Deno.PermissionName[] = [
+  "read",
+  "write",
+  "net",
+  "env",
+  "run",
+  "ffi",
+  "hrtime",
+];
+
+for (const name of permissions) {
+  Deno.bench({
+    name: `${name} false`,
+    permissions: {
+      [name]: false,
+    },
+    async fn() {
+      const status = await Deno.permissions.query({ name });
+      assertEquals(status.state, "prompt");
+    },
+  });
+
+  Deno.bench({
+    name: `${name} true`,
+    permissions: {
+      [name]: true,
+    },
+    async fn() {
+      const status = await Deno.permissions.query({ name });
+      assertEquals(status.state, "granted");
+    },
+  });
+}

cli/tests/testdata/bench/allow_none.out

@@ -0,0 +1,51 @@
+[WILDCARD]
+running 7 benches from [WILDCARD]
+bench read ... 1000 iterations FAILED [WILDCARD]
+bench write ... 1000 iterations FAILED [WILDCARD]
+bench net ... 1000 iterations FAILED [WILDCARD]
+bench env ... 1000 iterations FAILED [WILDCARD]
+bench run ... 1000 iterations FAILED [WILDCARD]
+bench ffi ... 1000 iterations FAILED [WILDCARD]
+bench hrtime ... 1000 iterations FAILED [WILDCARD]
+
+failures:
+
+read
+PermissionDenied: Can't escalate parent thread permissions
+[WILDCARD]
+
+write
+PermissionDenied: Can't escalate parent thread permissions
+[WILDCARD]
+
+net
+PermissionDenied: Can't escalate parent thread permissions
+[WILDCARD]
+
+env
+PermissionDenied: Can't escalate parent thread permissions
+[WILDCARD]
+
+run
+PermissionDenied: Can't escalate parent thread permissions
+[WILDCARD]
+
+ffi
+PermissionDenied: Can't escalate parent thread permissions
+[WILDCARD]
+
+hrtime
+PermissionDenied: Can't escalate parent thread permissions
+[WILDCARD]
+
+failures:
+
+	read
+	write
+	net
+	env
+	run
+	ffi
+	hrtime
+
+bench result: FAILED. 0 passed; 7 failed; 0 ignored; 0 measured; 0 filtered out [WILDCARD]

cli/tests/testdata/bench/allow_none.ts

@@ -0,0 +1,23 @@
+import { unreachable } from "../../../../test_util/std/testing/asserts.ts";
+
+const permissions: Deno.PermissionName[] = [
+  "read",
+  "write",
+  "net",
+  "env",
+  "run",
+  "ffi",
+  "hrtime",
+];
+
+for (const name of permissions) {
+  Deno.bench({
+    name,
+    permissions: {
+      [name]: true,
+    },
+    fn() {
+      unreachable();
+    },
+  });
+}

cli/tests/testdata/bench/clear_timeout.out

@@ -0,0 +1,8 @@
+Check [WILDCARD]/bench/clear_timeout.ts
+running 3 benches from [WILDCARD]/bench/clear_timeout.ts
+bench bench1 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench2 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench3 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+
+bench result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/clear_timeout.ts

@@ -0,0 +1,5 @@
+clearTimeout(setTimeout(() => {}, 1000));
+
+Deno.bench("bench1", () => {});
+Deno.bench("bench2", () => {});
+Deno.bench("bench3", () => {});

cli/tests/testdata/bench/collect.out

@@ -0,0 +1,5 @@
+Check [WILDCARD]/bench/collect/bench.ts
+running 0 benches from [WILDCARD]/bench/collect/bench.ts
+
+bench result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/collect/ignore/bench.ts

@@ -0,0 +1 @@
+throw new Error("this module should be ignored");

cli/tests/testdata/bench/exit_sanitizer.out

@@ -0,0 +1,35 @@
+Check [WILDCARD]/bench/exit_sanitizer.ts
+running 3 benches from [WILDCARD]/bench/exit_sanitizer.ts
+bench exit(0) ... 1000 iterations FAILED ([WILDCARD])
+bench exit(1) ... 1000 iterations FAILED ([WILDCARD])
+bench exit(2) ... 1000 iterations FAILED ([WILDCARD])
+
+failures:
+
+exit(0)
+AssertionError: Bench attempted to exit with exit code: 0
+    at [WILDCARD]
+    at [WILDCARD]/bench/exit_sanitizer.ts:2:8
+    at [WILDCARD]
+
+exit(1)
+AssertionError: Bench attempted to exit with exit code: 1
+    at [WILDCARD]
+    at [WILDCARD]/bench/exit_sanitizer.ts:6:8
+    at [WILDCARD]
+
+exit(2)
+AssertionError: Bench attempted to exit with exit code: 2
+    at [WILDCARD]
+    at [WILDCARD]/bench/exit_sanitizer.ts:10:8
+    at [WILDCARD]
+
+failures:
+
+	exit(0)
+	exit(1)
+	exit(2)
+
+bench result: FAILED. 0 passed; 3 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+
+error: Bench failed

cli/tests/testdata/bench/exit_sanitizer.ts

@@ -0,0 +1,11 @@
+Deno.bench("exit(0)", function () {
+  Deno.exit(0);
+});
+
+Deno.bench("exit(1)", function () {
+  Deno.exit(1);
+});
+
+Deno.bench("exit(2)", function () {
+  Deno.exit(2);
+});

cli/tests/testdata/bench/fail.out

@@ -0,0 +1,81 @@
+Check [WILDCARD]/bench/fail.ts
+running 10 benches from [WILDCARD]/bench/fail.ts
+bench bench0 ... 1000 iterations FAILED ([WILDCARD])
+bench bench1 ... 1000 iterations FAILED ([WILDCARD])
+bench bench2 ... 1000 iterations FAILED ([WILDCARD])
+bench bench3 ... 1000 iterations FAILED ([WILDCARD])
+bench bench4 ... 1000 iterations FAILED ([WILDCARD])
+bench bench5 ... 1000 iterations FAILED ([WILDCARD])
+bench bench6 ... 1000 iterations FAILED ([WILDCARD])
+bench bench7 ... 1000 iterations FAILED ([WILDCARD])
+bench bench8 ... 1000 iterations FAILED ([WILDCARD])
+bench bench9 ... 1000 iterations FAILED ([WILDCARD])
+
+failures:
+
+bench0
+Error
+    at [WILDCARD]/bench/fail.ts:2:9
+    at [WILDCARD]
+
+bench1
+Error
+    at [WILDCARD]/bench/fail.ts:5:9
+    at [WILDCARD]
+
+bench2
+Error
+    at [WILDCARD]/bench/fail.ts:8:9
+    at [WILDCARD]
+
+bench3
+Error
+    at [WILDCARD]/bench/fail.ts:11:9
+    at [WILDCARD]
+
+bench4
+Error
+    at [WILDCARD]/bench/fail.ts:14:9
+    at [WILDCARD]
+
+bench5
+Error
+    at [WILDCARD]/bench/fail.ts:17:9
+    at [WILDCARD]
+
+bench6
+Error
+    at [WILDCARD]/bench/fail.ts:20:9
+    at [WILDCARD]
+
+bench7
+Error
+    at [WILDCARD]/bench/fail.ts:23:9
+    at [WILDCARD]
+
+bench8
+Error
+    at [WILDCARD]/bench/fail.ts:26:9
+    at [WILDCARD]
+
+bench9
+Error
+    at [WILDCARD]/bench/fail.ts:29:9
+    at [WILDCARD]
+
+failures:
+
+	bench0
+	bench1
+	bench2
+	bench3
+	bench4
+	bench5
+	bench6
+	bench7
+	bench8
+	bench9
+
+bench result: FAILED. 0 passed; 10 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+
+error: Bench failed

cli/tests/testdata/bench/fail.ts

@@ -0,0 +1,30 @@
+Deno.bench("bench0", () => {
+  throw new Error();
+});
+Deno.bench("bench1", () => {
+  throw new Error();
+});
+Deno.bench("bench2", () => {
+  throw new Error();
+});
+Deno.bench("bench3", () => {
+  throw new Error();
+});
+Deno.bench("bench4", () => {
+  throw new Error();
+});
+Deno.bench("bench5", () => {
+  throw new Error();
+});
+Deno.bench("bench6", () => {
+  throw new Error();
+});
+Deno.bench("bench7", () => {
+  throw new Error();
+});
+Deno.bench("bench8", () => {
+  throw new Error();
+});
+Deno.bench("bench9", () => {
+  throw new Error();
+});

cli/tests/testdata/bench/filter.out

@@ -0,0 +1,12 @@
+Check [WILDCARD]/bench/filter/a_bench.ts
+Check [WILDCARD]/bench/filter/b_bench.ts
+Check [WILDCARD]/bench/filter/c_bench.ts
+running 1 bench from [WILDCARD]/bench/filter/a_bench.ts
+bench foo ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+running 1 bench from [WILDCARD]/bench/filter/b_bench.ts
+bench foo ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+running 1 bench from [WILDCARD]/bench/filter/c_bench.ts
+bench foo ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+
+bench result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 6 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/filter/a_bench.ts

@@ -0,0 +1,3 @@
+Deno.bench("foo", function () {});
+Deno.bench("bar", function () {});
+Deno.bench("baz", function () {});

cli/tests/testdata/bench/filter/b_bench.ts

@@ -0,0 +1,3 @@
+Deno.bench("foo", function () {});
+Deno.bench("bar", function () {});
+Deno.bench("baz", function () {});

cli/tests/testdata/bench/filter/c_bench.ts

@@ -0,0 +1,3 @@
+Deno.bench("foo", function () {});
+Deno.bench("bar", function () {});
+Deno.bench("baz", function () {});

cli/tests/testdata/bench/finally_timeout.out

@@ -0,0 +1,19 @@
+Check [WILDCARD]/bench/finally_timeout.ts
+running 2 benches from [WILDCARD]/bench/finally_timeout.ts
+bench error ... 1000 iterations FAILED ([WILDCARD])
+bench success ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+
+failures:
+
+error
+Error: fail
+    at [WILDCARD]/bench/finally_timeout.ts:4:11
+    at [WILDCARD]
+
+failures:
+
+	error
+
+bench result: FAILED. 1 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+
+error: Bench failed

cli/tests/testdata/bench/finally_timeout.ts

@@ -0,0 +1,11 @@
+Deno.bench("error", function () {
+  const timer = setTimeout(() => null, 10000);
+  try {
+    throw new Error("fail");
+  } finally {
+    clearTimeout(timer);
+  }
+});
+
+Deno.bench("success", function () {
+});

cli/tests/testdata/bench/ignore.out

@@ -0,0 +1,15 @@
+Check [WILDCARD]/bench/ignore.ts
+running 10 benches from [WILDCARD]/bench/ignore.ts
+bench bench0 ... 1000 iterations ignored ([WILDCARD])
+bench bench1 ... 1000 iterations ignored ([WILDCARD])
+bench bench2 ... 1000 iterations ignored ([WILDCARD])
+bench bench3 ... 1000 iterations ignored ([WILDCARD])
+bench bench4 ... 1000 iterations ignored ([WILDCARD])
+bench bench5 ... 1000 iterations ignored ([WILDCARD])
+bench bench6 ... 1000 iterations ignored ([WILDCARD])
+bench bench7 ... 1000 iterations ignored ([WILDCARD])
+bench bench8 ... 1000 iterations ignored ([WILDCARD])
+bench bench9 ... 1000 iterations ignored ([WILDCARD])
+
+bench result: ok. 0 passed; 0 failed; 10 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/ignore.ts

@@ -0,0 +1,9 @@
+for (let i = 0; i < 10; i++) {
+  Deno.bench({
+    name: `bench${i}`,
+    ignore: true,
+    fn() {
+      throw new Error("unreachable");
+    },
+  });
+}

cli/tests/testdata/bench/ignore_permissions.out

@@ -0,0 +1,6 @@
+Check [WILDCARD]/bench/ignore_permissions.ts
+running 1 bench from [WILDCARD]/bench/ignore_permissions.ts
+bench ignore ... 1000 iterations ignored ([WILDCARD])
+
+bench result: ok. 0 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/ignore_permissions.ts

@@ -0,0 +1,16 @@
+Deno.bench({
+  name: "ignore",
+  permissions: {
+    read: true,
+    write: true,
+    net: true,
+    env: true,
+    run: true,
+    ffi: true,
+    hrtime: true,
+  },
+  ignore: true,
+  fn() {
+    throw new Error("unreachable");
+  },
+});

cli/tests/testdata/bench/interval.out

@@ -0,0 +1,5 @@
+Check [WILDCARD]/bench/interval.ts
+running 0 benches from [WILDCARD]/bench/interval.ts
+
+bench result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/interval.ts

@@ -0,0 +1 @@
+setInterval(function () {}, 0);

cli/tests/testdata/bench/load_unload.out

@@ -0,0 +1,6 @@
+Check [WILDCARD]/bench/load_unload.ts
+running 1 bench from [WILDCARD]/bench/load_unload.ts
+bench bench ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+
+bench result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/load_unload.ts

@@ -0,0 +1,22 @@
+let interval: number | null = null;
+addEventListener("load", () => {
+  if (interval) {
+    throw new Error("Interval is already set");
+  }
+
+  interval = setInterval(() => {}, 0);
+});
+
+addEventListener("unload", () => {
+  if (!interval) {
+    throw new Error("Interval was not set");
+  }
+
+  clearInterval(interval);
+});
+
+Deno.bench("bench", () => {
+  if (!interval) {
+    throw new Error("Interval was not set");
+  }
+});

cli/tests/testdata/bench/meta.out

@@ -0,0 +1,7 @@
+Check [WILDCARD]/bench/meta.ts
+import.meta.main: false
+import.meta.url: [WILDCARD]/bench/meta.ts
+running 0 benches from [WILDCARD]/bench/meta.ts
+
+bench result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/meta.ts

@@ -0,0 +1,2 @@
+console.log("import.meta.main: %s", import.meta.main);
+console.log("import.meta.url: %s", import.meta.url);

cli/tests/testdata/bench/no_check.out

@@ -0,0 +1,8 @@
+
+bench result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+
+error: Uncaught TypeError: Cannot read properties of undefined (reading 'fn')
+Deno.bench();
+     ^
+    at [WILDCARD]
+    at [WILDCARD]/bench/no_check.ts:1:6

cli/tests/testdata/bench/no_check.ts

@@ -0,0 +1 @@
+Deno.bench();

cli/tests/testdata/bench/no_color.ts

@@ -0,0 +1,17 @@
+Deno.bench({
+  name: "success",
+  fn() {},
+});
+
+Deno.bench({
+  name: "fail",
+  fn() {
+    throw new Error("fail");
+  },
+});
+
+Deno.bench({
+  name: "ignored",
+  ignore: true,
+  fn() {},
+});

cli/tests/testdata/bench/no_prompt_by_default.out

@@ -0,0 +1,17 @@
+Check [WILDCARD]no_prompt_by_default.ts
+running 1 bench from [WILDCARD]no_prompt_by_default.ts
+bench no prompt ... 1000 iterations FAILED ([WILDCARD]ms)
+
+failures:
+
+no prompt
+PermissionDenied: Requires read access to "./some_file.txt", run again with the --allow-read flag
+[WILDCARD]
+
+failures:
+
+	no prompt
+
+bench result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD]ms)
+
+error: Bench failed

cli/tests/testdata/bench/no_prompt_by_default.ts

@@ -0,0 +1,3 @@
+Deno.bench("no prompt", async () => {
+  await Deno.readTextFile("./some_file.txt");
+});

cli/tests/testdata/bench/no_prompt_with_denied_perms.out

@@ -0,0 +1,17 @@
+Check [WILDCARD]/no_prompt_with_denied_perms.ts
+running 1 bench from [WILDCARD]/no_prompt_with_denied_perms.ts
+bench no prompt ... 1000 iterations FAILED ([WILDCARD]ms)
+
+failures:
+
+no prompt
+PermissionDenied: Requires read access to "./some_file.txt", run again with the --allow-read flag
+[WILDCARD]
+
+failures:
+
+	no prompt
+
+bench result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD]ms)
+
+error: Bench failed

cli/tests/testdata/bench/no_prompt_with_denied_perms.ts

@@ -0,0 +1,3 @@
+Deno.bench("no prompt", { permissions: { read: false } }, async () => {
+  await Deno.readTextFile("./some_file.txt");
+});

cli/tests/testdata/bench/only.out

@@ -0,0 +1,7 @@
+Check [WILDCARD]/bench/only.ts
+running 1 bench from [WILDCARD]/bench/only.ts
+bench only ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+
+bench result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 2 filtered out ([WILDCARD])
+
+error: Bench failed because the "only" option was used

cli/tests/testdata/bench/only.ts

@@ -0,0 +1,15 @@
+Deno.bench({
+  name: "before",
+  fn() {},
+});
+
+Deno.bench({
+  only: true,
+  name: "only",
+  fn() {},
+});
+
+Deno.bench({
+  name: "after",
+  fn() {},
+});

cli/tests/testdata/bench/overloads.out

@@ -0,0 +1,11 @@
+Check [WILDCARD]/bench/overloads.ts
+running 6 benches from [WILDCARD]/bench/overloads.ts
+bench bench0 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench1 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench2 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench3 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench4 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench5 ... 1000 iterations ignored ([WILDCARD])
+
+bench result: ok. 5 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/overloads.ts

@@ -0,0 +1,6 @@
+Deno.bench("bench0", () => {});
+Deno.bench(function bench1() {});
+Deno.bench({ name: "bench2", fn: () => {} });
+Deno.bench("bench3", { permissions: "none" }, () => {});
+Deno.bench({ name: "bench4" }, () => {});
+Deno.bench({ ignore: true }, function bench5() {});

cli/tests/testdata/bench/pass.out

@@ -0,0 +1,15 @@
+Check [WILDCARD]/bench/pass.ts
+running 10 benches from [WILDCARD]/bench/pass.ts
+bench bench0 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench1 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench2 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench3 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench4 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench5 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench6 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench7 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench8 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+bench bench9 ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok ([WILDCARD])
+
+bench result: ok. 10 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/pass.ts

@@ -0,0 +1,10 @@
+Deno.bench("bench0", () => {});
+Deno.bench("bench1", () => {});
+Deno.bench("bench2", () => {});
+Deno.bench("bench3", () => {});
+Deno.bench("bench4", () => {});
+Deno.bench("bench5", () => {});
+Deno.bench("bench6", () => {});
+Deno.bench("bench7", () => {});
+Deno.bench("bench8", () => {});
+Deno.bench("bench9", () => {});

cli/tests/testdata/bench/quiet.out

@@ -0,0 +1,8 @@
+running 4 benches from [WILDCARD]/bench/quiet.ts
+bench console.log ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench console.error ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench console.info ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+bench console.warn ... 1000 iterations [WILDCARD] ns/iter ([WILDCARD]..[WILDCARD] ns/iter) ok [WILDCARD]
+
+bench result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/bench/quiet.ts

@@ -0,0 +1,15 @@
+Deno.bench("console.log", function () {
+  console.log("log");
+});
+
+Deno.bench("console.error", function () {
+  console.error("error");
+});
+
+Deno.bench("console.info", function () {
+  console.info("info");
+});
+
+Deno.bench("console.warn", function () {
+  console.info("warn");
+});

cli/tests/testdata/bench/unhandled_rejection.out

@@ -0,0 +1,10 @@
+Check [WILDCARD]/bench/unhandled_rejection.ts
+
+bench result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+
+error: Uncaught (in promise) Error: rejection
+  reject(new Error("rejection"));
+         ^
+    at [WILDCARD]/bench/unhandled_rejection.ts:2:10
+    at new Promise (<anonymous>)
+    at [WILDCARD]/bench/unhandled_rejection.ts:1:1

cli/tests/testdata/bench/unhandled_rejection.ts

@@ -0,0 +1,3 @@
+new Promise((_resolve, reject) => {
+  reject(new Error("rejection"));
+});

cli/tests/testdata/bench/unresolved_promise.out

@@ -0,0 +1,5 @@
+Check [WILDCARD]/bench/unresolved_promise.ts
+
+bench result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+
+error: Module evaluation is still pending but there are no pending ops or dynamic imports. This situation is often caused by unresolved promises.

cli/tests/testdata/bench/unresolved_promise.ts

@@ -0,0 +1 @@
+await new Promise((_resolve, _reject) => {});

cli/tools/bench.rs

@@ -0,0 +1,727 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use crate::cache;
+use crate::cache::CacherLoader;
+use crate::colors;
+use crate::compat;
+use crate::create_main_worker;
+use crate::display;
+use crate::emit;
+use crate::file_watcher;
+use crate::file_watcher::ResolutionResult;
+use crate::flags::BenchFlags;
+use crate::flags::CheckFlag;
+use crate::flags::Flags;
+use crate::fs_util::collect_specifiers;
+use crate::fs_util::is_supported_bench_path;
+use crate::graph_util::contains_specifier;
+use crate::graph_util::graph_valid;
+use crate::located_script_name;
+use crate::lockfile;
+use crate::ops;
+use crate::proc_state::ProcState;
+use crate::resolver::ImportMapResolver;
+use crate::resolver::JsxResolver;
+
+use deno_core::error::generic_error;
+use deno_core::error::AnyError;
+use deno_core::futures::future;
+use deno_core::futures::stream;
+use deno_core::futures::FutureExt;
+use deno_core::futures::StreamExt;
+use deno_core::serde_json::json;
+use deno_core::ModuleSpecifier;
+use deno_graph::ModuleKind;
+use deno_runtime::permissions::Permissions;
+use deno_runtime::tokio_util::run_basic;
+use log::Level;
+use num_format::Locale;
+use num_format::ToFormattedString;
+use serde::Deserialize;
+use std::collections::HashSet;
+use std::io::Write;
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::time::Duration;
+use std::time::Instant;
+use tokio::sync::mpsc::unbounded_channel;
+use tokio::sync::mpsc::UnboundedSender;
+
+#[derive(Debug, Clone, Deserialize)]
+struct BenchSpecifierOptions {
+  compat_mode: bool,
+  filter: Option<String>,
+}
+
+#[derive(Debug, Clone, PartialEq, Deserialize, Eq, Hash)]
+#[serde(rename_all = "camelCase")]
+pub struct BenchDescription {
+  pub origin: String,
+  pub name: String,
+  pub iterations: u64,
+}
+
+#[derive(Debug, Clone, PartialEq, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub enum BenchOutput {
+  Console(String),
+}
+
+#[derive(Debug, Clone, PartialEq, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub enum BenchResult {
+  Ok,
+  Ignored,
+  Failed(String),
+}
+
+#[derive(Debug, Clone, PartialEq, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct BenchPlan {
+  pub origin: String,
+  pub total: usize,
+  pub filtered_out: usize,
+  pub used_only: bool,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub enum BenchEvent {
+  Plan(BenchPlan),
+  Wait(BenchDescription),
+  Output(BenchOutput),
+  IterationTime(u64),
+  Result(BenchDescription, BenchResult, u64),
+}
+
+#[derive(Debug, Clone)]
+pub struct BenchMeasures {
+  pub iterations: u64,
+  pub current_start: Instant,
+  pub measures: Vec<u128>,
+}
+
+#[derive(Debug, Clone)]
+pub struct BenchSummary {
+  pub total: usize,
+  pub passed: usize,
+  pub failed: usize,
+  pub ignored: usize,
+  pub filtered_out: usize,
+  pub measured: usize,
+  pub measures: Vec<BenchMeasures>,
+  pub current_bench: BenchMeasures,
+  pub failures: Vec<(BenchDescription, String)>,
+}
+
+impl BenchSummary {
+  pub fn new() -> Self {
+    Self {
+      total: 0,
+      passed: 0,
+      failed: 0,
+      ignored: 0,
+      filtered_out: 0,
+      measured: 0,
+      measures: Vec::new(),
+      current_bench: BenchMeasures {
+        iterations: 0,
+        current_start: Instant::now(),
+        measures: vec![],
+      },
+      failures: Vec::new(),
+    }
+  }
+
+  fn has_failed(&self) -> bool {
+    self.failed > 0 || !self.failures.is_empty()
+  }
+
+  fn has_pending(&self) -> bool {
+    self.total - self.passed - self.failed - self.ignored > 0
+  }
+}
+
+pub trait BenchReporter {
+  fn report_plan(&mut self, plan: &BenchPlan);
+  fn report_wait(&mut self, description: &BenchDescription);
+  fn report_output(&mut self, output: &BenchOutput);
+  fn report_result(
+    &mut self,
+    description: &BenchDescription,
+    result: &BenchResult,
+    elapsed: u64,
+    current_bench: &BenchMeasures,
+  );
+  fn report_summary(&mut self, summary: &BenchSummary, elapsed: &Duration);
+}
+
+struct PrettyBenchReporter {
+  echo_output: bool,
+}
+
+impl PrettyBenchReporter {
+  fn new(echo_output: bool) -> Self {
+    Self { echo_output }
+  }
+
+  fn force_report_wait(&mut self, description: &BenchDescription) {
+    print!(
+      "bench {} ... {} iterations ",
+      description.name, description.iterations
+    );
+    // flush for faster feedback when line buffered
+    std::io::stdout().flush().unwrap();
+  }
+}
+
+impl BenchReporter for PrettyBenchReporter {
+  fn report_plan(&mut self, plan: &BenchPlan) {
+    let inflection = if plan.total == 1 { "bench" } else { "benches" };
+    println!("running {} {} from {}", plan.total, inflection, plan.origin);
+  }
+
+  fn report_wait(&mut self, description: &BenchDescription) {
+    self.force_report_wait(description);
+  }
+
+  fn report_output(&mut self, output: &BenchOutput) {
+    if self.echo_output {
+      match output {
+        BenchOutput::Console(line) => print!("{}", line),
+      }
+    }
+  }
+
+  fn report_result(
+    &mut self,
+    _description: &BenchDescription,
+    result: &BenchResult,
+    elapsed: u64,
+    current_bench: &BenchMeasures,
+  ) {
+    let status = match result {
+      BenchResult::Ok => {
+        let ns_op = current_bench.measures.iter().sum::<u128>()
+          / current_bench.iterations as u128;
+        let min_op = current_bench.measures.iter().min().unwrap_or(&0);
+        let max_op = current_bench.measures.iter().max().unwrap_or(&0);
+        format!(
+          "{} ns/iter ({}..{} ns/iter) {}",
+          ns_op.to_formatted_string(&Locale::en),
+          min_op.to_formatted_string(&Locale::en),
+          max_op.to_formatted_string(&Locale::en),
+          colors::green("ok")
+        )
+      }
+      BenchResult::Ignored => colors::yellow("ignored").to_string(),
+      BenchResult::Failed(_) => colors::red("FAILED").to_string(),
+    };
+
+    println!(
+      "{} {}",
+      status,
+      colors::gray(format!("({})", display::human_elapsed(elapsed.into())))
+    );
+  }
+
+  fn report_summary(&mut self, summary: &BenchSummary, elapsed: &Duration) {
+    if !summary.failures.is_empty() {
+      println!("\nfailures:\n");
+      for (description, error) in &summary.failures {
+        println!("{}", description.name);
+        println!("{}", error);
+        println!();
+      }
+
+      println!("failures:\n");
+      for (description, _) in &summary.failures {
+        println!("\t{}", description.name);
+      }
+    }
+
+    let status = if summary.has_failed() || summary.has_pending() {
+      colors::red("FAILED").to_string()
+    } else {
+      colors::green("ok").to_string()
+    };
+
+    println!(
+      "\nbench result: {}. {} passed; {} failed; {} ignored; {} measured; {} filtered out {}\n",
+      status,
+      summary.passed,
+      summary.failed,
+      summary.ignored,
+      summary.measured,
+      summary.filtered_out,
+      colors::gray(format!("({})", display::human_elapsed(elapsed.as_millis()))),
+    );
+  }
+}
+
+fn create_reporter(echo_output: bool) -> Box<dyn BenchReporter + Send> {
+  Box::new(PrettyBenchReporter::new(echo_output))
+}
+
+/// Type check a collection of module and document specifiers.
+async fn check_specifiers(
+  ps: &ProcState,
+  permissions: Permissions,
+  specifiers: Vec<ModuleSpecifier>,
+  lib: emit::TypeLib,
+) -> Result<(), AnyError> {
+  ps.prepare_module_load(
+    specifiers,
+    false,
+    lib,
+    Permissions::allow_all(),
+    permissions,
+    true,
+  )
+  .await?;
+
+  Ok(())
+}
+
+/// Run a single specifier as an executable bench module.
+async fn bench_specifier(
+  ps: ProcState,
+  permissions: Permissions,
+  specifier: ModuleSpecifier,
+  channel: UnboundedSender<BenchEvent>,
+  options: BenchSpecifierOptions,
+) -> Result<(), AnyError> {
+  let mut worker = create_main_worker(
+    &ps,
+    specifier.clone(),
+    permissions,
+    vec![ops::bench::init(channel.clone())],
+  );
+
+  if options.compat_mode {
+    worker.execute_side_module(&compat::GLOBAL_URL).await?;
+    worker.execute_side_module(&compat::MODULE_URL).await?;
+
+    let use_esm_loader = compat::check_if_should_use_esm_loader(&specifier)?;
+
+    if use_esm_loader {
+      worker.execute_side_module(&specifier).await?;
+    } else {
+      compat::load_cjs_module(
+        &mut worker.js_runtime,
+        &specifier.to_file_path().unwrap().display().to_string(),
+        false,
+      )?;
+      worker.run_event_loop(false).await?;
+    }
+  } else {
+    // We execute the module module as a side module so that import.meta.main is not set.
+    worker.execute_side_module(&specifier).await?;
+  }
+
+  worker.dispatch_load_event(&located_script_name!())?;
+
+  let bench_result = worker.js_runtime.execute_script(
+    &located_script_name!(),
+    &format!(
+      r#"Deno[Deno.internal].runBenchmarks({})"#,
+      json!({
+        "filter": options.filter,
+      }),
+    ),
+  )?;
+
+  worker.js_runtime.resolve_value(bench_result).await?;
+
+  worker.dispatch_unload_event(&located_script_name!())?;
+
+  Ok(())
+}
+
+/// Test a collection of specifiers with test modes concurrently.
+async fn bench_specifiers(
+  ps: ProcState,
+  permissions: Permissions,
+  specifiers: Vec<ModuleSpecifier>,
+  options: BenchSpecifierOptions,
+) -> Result<(), AnyError> {
+  let log_level = ps.flags.log_level;
+
+  let (sender, mut receiver) = unbounded_channel::<BenchEvent>();
+
+  let join_handles = specifiers.iter().map(move |specifier| {
+    let ps = ps.clone();
+    let permissions = permissions.clone();
+    let specifier = specifier.clone();
+    let sender = sender.clone();
+    let options = options.clone();
+
+    tokio::task::spawn_blocking(move || {
+      let future = bench_specifier(ps, permissions, specifier, sender, options);
+
+      run_basic(future)
+    })
+  });
+
+  let join_stream = stream::iter(join_handles)
+    .buffer_unordered(1)
+    .collect::<Vec<Result<Result<(), AnyError>, tokio::task::JoinError>>>();
+
+  let mut reporter = create_reporter(log_level != Some(Level::Error));
+
+  let handler = {
+    tokio::task::spawn(async move {
+      let earlier = Instant::now();
+      let mut summary = BenchSummary::new();
+      let mut used_only = false;
+
+      while let Some(event) = receiver.recv().await {
+        match event {
+          BenchEvent::Plan(plan) => {
+            summary.total += plan.total;
+            summary.filtered_out += plan.filtered_out;
+
+            if plan.used_only {
+              used_only = true;
+            }
+
+            reporter.report_plan(&plan);
+          }
+
+          BenchEvent::Wait(description) => {
+            reporter.report_wait(&description);
+            summary.current_bench = BenchMeasures {
+              iterations: description.iterations,
+              current_start: Instant::now(),
+              measures: Vec::with_capacity(
+                description.iterations.try_into().unwrap(),
+              ),
+            };
+          }
+
+          BenchEvent::Output(output) => {
+            reporter.report_output(&output);
+          }
+
+          BenchEvent::IterationTime(iter_time) => {
+            summary.current_bench.measures.push(iter_time.into())
+          }
+
+          BenchEvent::Result(description, result, elapsed) => {
+            match &result {
+              BenchResult::Ok => {
+                summary.passed += 1;
+              }
+              BenchResult::Ignored => {
+                summary.ignored += 1;
+              }
+              BenchResult::Failed(error) => {
+                summary.failed += 1;
+                summary.failures.push((description.clone(), error.clone()));
+              }
+            }
+
+            reporter.report_result(
+              &description,
+              &result,
+              elapsed,
+              &summary.current_bench,
+            );
+          }
+        }
+      }
+
+      let elapsed = Instant::now().duration_since(earlier);
+      reporter.report_summary(&summary, &elapsed);
+
+      if used_only {
+        return Err(generic_error(
+          "Bench failed because the \"only\" option was used",
+        ));
+      }
+
+      if summary.failed > 0 {
+        return Err(generic_error("Bench failed"));
+      }
+
+      Ok(())
+    })
+  };
+
+  let (join_results, result) = future::join(join_stream, handler).await;
+
+  // propagate any errors
+  for join_result in join_results {
+    join_result??;
+  }
+
+  result??;
+
+  Ok(())
+}
+
+pub async fn run_benchmarks(
+  flags: Flags,
+  bench_flags: BenchFlags,
+) -> Result<(), AnyError> {
+  let ps = ProcState::build(Arc::new(flags)).await?;
+  let permissions = Permissions::from_options(&ps.flags.permissions_options());
+  let specifiers = collect_specifiers(
+    bench_flags.include.unwrap_or_else(|| vec![".".to_string()]),
+    &bench_flags.ignore.clone(),
+    is_supported_bench_path,
+  )?;
+
+  if specifiers.is_empty() {
+    return Err(generic_error("No bench modules found"));
+  }
+
+  let lib = if ps.flags.unstable {
+    emit::TypeLib::UnstableDenoWindow
+  } else {
+    emit::TypeLib::DenoWindow
+  };
+
+  check_specifiers(&ps, permissions.clone(), specifiers.clone(), lib).await?;
+
+  let compat = ps.flags.compat;
+  bench_specifiers(
+    ps,
+    permissions,
+    specifiers,
+    BenchSpecifierOptions {
+      compat_mode: compat,
+      filter: bench_flags.filter,
+    },
+  )
+  .await?;
+
+  Ok(())
+}
+
+// TODO(bartlomieju): heavy duplication of code with `cli/tools/test.rs`
+pub async fn run_benchmarks_with_watch(
+  flags: Flags,
+  bench_flags: BenchFlags,
+) -> Result<(), AnyError> {
+  let flags = Arc::new(flags);
+  let ps = ProcState::build(flags.clone()).await?;
+  let permissions = Permissions::from_options(&flags.permissions_options());
+
+  let lib = if flags.unstable {
+    emit::TypeLib::UnstableDenoWindow
+  } else {
+    emit::TypeLib::DenoWindow
+  };
+
+  let include = bench_flags.include.unwrap_or_else(|| vec![".".to_string()]);
+  let ignore = bench_flags.ignore.clone();
+  let paths_to_watch: Vec<_> = include.iter().map(PathBuf::from).collect();
+  let no_check = ps.flags.check == CheckFlag::None;
+
+  let resolver = |changed: Option<Vec<PathBuf>>| {
+    let mut cache = cache::FetchCacher::new(
+      ps.dir.gen_cache.clone(),
+      ps.file_fetcher.clone(),
+      Permissions::allow_all(),
+      Permissions::allow_all(),
+    );
+
+    let paths_to_watch = paths_to_watch.clone();
+    let paths_to_watch_clone = paths_to_watch.clone();
+
+    let maybe_import_map_resolver =
+      ps.maybe_import_map.clone().map(ImportMapResolver::new);
+    let maybe_jsx_resolver = ps.maybe_config_file.as_ref().and_then(|cf| {
+      cf.to_maybe_jsx_import_source_module()
+        .map(|im| JsxResolver::new(im, maybe_import_map_resolver.clone()))
+    });
+    let maybe_locker = lockfile::as_maybe_locker(ps.lockfile.clone());
+    let maybe_imports = ps
+      .maybe_config_file
+      .as_ref()
+      .map(|cf| cf.to_maybe_imports());
+    let files_changed = changed.is_some();
+    let include = include.clone();
+    let ignore = ignore.clone();
+    let check_js = ps
+      .maybe_config_file
+      .as_ref()
+      .map(|cf| cf.get_check_js())
+      .unwrap_or(false);
+
+    async move {
+      let bench_modules =
+        collect_specifiers(include.clone(), &ignore, is_supported_bench_path)?;
+
+      let mut paths_to_watch = paths_to_watch_clone;
+      let mut modules_to_reload = if files_changed {
+        Vec::new()
+      } else {
+        bench_modules
+          .iter()
+          .map(|url| (url.clone(), ModuleKind::Esm))
+          .collect()
+      };
+      let maybe_imports = if let Some(result) = maybe_imports {
+        result?
+      } else {
+        None
+      };
+      let maybe_resolver = if maybe_jsx_resolver.is_some() {
+        maybe_jsx_resolver.as_ref().map(|jr| jr.as_resolver())
+      } else {
+        maybe_import_map_resolver
+          .as_ref()
+          .map(|im| im.as_resolver())
+      };
+      let graph = deno_graph::create_graph(
+        bench_modules
+          .iter()
+          .map(|s| (s.clone(), ModuleKind::Esm))
+          .collect(),
+        false,
+        maybe_imports,
+        cache.as_mut_loader(),
+        maybe_resolver,
+        maybe_locker,
+        None,
+        None,
+      )
+      .await;
+      graph_valid(&graph, !no_check, check_js)?;
+
+      // TODO(@kitsonk) - This should be totally derivable from the graph.
+      for specifier in bench_modules {
+        fn get_dependencies<'a>(
+          graph: &'a deno_graph::ModuleGraph,
+          maybe_module: Option<&'a deno_graph::Module>,
+          // This needs to be accessible to skip getting dependencies if they're already there,
+          // otherwise this will cause a stack overflow with circular dependencies
+          output: &mut HashSet<&'a ModuleSpecifier>,
+          no_check: bool,
+        ) {
+          if let Some(module) = maybe_module {
+            for dep in module.dependencies.values() {
+              if let Some(specifier) = &dep.get_code() {
+                if !output.contains(specifier) {
+                  output.insert(specifier);
+                  get_dependencies(
+                    graph,
+                    graph.get(specifier),
+                    output,
+                    no_check,
+                  );
+                }
+              }
+              if !no_check {
+                if let Some(specifier) = &dep.get_type() {
+                  if !output.contains(specifier) {
+                    output.insert(specifier);
+                    get_dependencies(
+                      graph,
+                      graph.get(specifier),
+                      output,
+                      no_check,
+                    );
+                  }
+                }
+              }
+            }
+          }
+        }
+
+        // This bench module and all it's dependencies
+        let mut modules = HashSet::new();
+        modules.insert(&specifier);
+        get_dependencies(&graph, graph.get(&specifier), &mut modules, no_check);
+
+        paths_to_watch.extend(
+          modules
+            .iter()
+            .filter_map(|specifier| specifier.to_file_path().ok()),
+        );
+
+        if let Some(changed) = &changed {
+          for path in changed.iter().filter_map(|path| {
+            deno_core::resolve_url_or_path(&path.to_string_lossy()).ok()
+          }) {
+            if modules.contains(&&path) {
+              modules_to_reload.push((specifier, ModuleKind::Esm));
+              break;
+            }
+          }
+        }
+      }
+
+      Ok((paths_to_watch, modules_to_reload))
+    }
+    .map(move |result| {
+      if files_changed
+        && matches!(result, Ok((_, ref modules)) if modules.is_empty())
+      {
+        ResolutionResult::Ignore
+      } else {
+        match result {
+          Ok((paths_to_watch, modules_to_reload)) => {
+            ResolutionResult::Restart {
+              paths_to_watch,
+              result: Ok(modules_to_reload),
+            }
+          }
+          Err(e) => ResolutionResult::Restart {
+            paths_to_watch,
+            result: Err(e),
+          },
+        }
+      }
+    })
+  };
+
+  let operation = |modules_to_reload: Vec<(ModuleSpecifier, ModuleKind)>| {
+    let flags = flags.clone();
+    let filter = bench_flags.filter.clone();
+    let include = include.clone();
+    let ignore = ignore.clone();
+    let lib = lib.clone();
+    let permissions = permissions.clone();
+    let ps = ps.clone();
+
+    async move {
+      let specifiers =
+        collect_specifiers(include.clone(), &ignore, is_supported_bench_path)?
+          .iter()
+          .filter(|specifier| contains_specifier(&modules_to_reload, specifier))
+          .cloned()
+          .collect::<Vec<ModuleSpecifier>>();
+
+      check_specifiers(&ps, permissions.clone(), specifiers.clone(), lib)
+        .await?;
+
+      bench_specifiers(
+        ps,
+        permissions.clone(),
+        specifiers,
+        BenchSpecifierOptions {
+          compat_mode: flags.compat,
+          filter: filter.clone(),
+        },
+      )
+      .await?;
+
+      Ok(())
+    }
+  };
+
+  file_watcher::watch_func(
+    resolver,
+    operation,
+    file_watcher::PrintConfig {
+      job_name: "Bench".to_string(),
+      clear_screen: !flags.no_clear_screen,
+    },
+  )
+  .await?;
+
+  Ok(())
+}

cli/tools/mod.rs

@@ -1,5 +1,6 @@
 // Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
 
+pub mod bench;
 pub mod coverage;
 pub mod doc;
 pub mod fmt;

runtime/js/40_testing.js

@@ -409,12 +409,14 @@
 
   // Wrap test function in additional assertion that makes sure
   // that the test case does not accidentally exit prematurely.
-  function assertExit(fn) {
+  function assertExit(fn, isTest) {
     return async function exitSanitizer(...params) {
       setExitHandler((exitCode) => {
         assert(
           false,
-          `Test case attempted to exit with exit code: ${exitCode}`,
+          `${
+            isTest ? "Test case" : "Bench"
+          } attempted to exit with exit code: ${exitCode}`,
         );
       });
 
@@ -528,6 +530,7 @@
   }
 
   const tests = [];
+  const benches = [];
 
   // Main test function provided by Deno.
   function test(
@@ -627,6 +630,107 @@
     ArrayPrototypePush(tests, testDef);
   }
 
+  // Main bench function provided by Deno.
+  function bench(
+    nameOrFnOrOptions,
+    optionsOrFn,
+    maybeFn,
+  ) {
+    let benchDef;
+    const defaults = {
+      ignore: false,
+      only: false,
+      sanitizeOps: true,
+      sanitizeResources: true,
+      sanitizeExit: true,
+      permissions: null,
+    };
+
+    if (typeof nameOrFnOrOptions === "string") {
+      if (!nameOrFnOrOptions) {
+        throw new TypeError("The bench name can't be empty");
+      }
+      if (typeof optionsOrFn === "function") {
+        benchDef = { fn: optionsOrFn, name: nameOrFnOrOptions, ...defaults };
+      } else {
+        if (!maybeFn || typeof maybeFn !== "function") {
+          throw new TypeError("Missing bench function");
+        }
+        if (optionsOrFn.fn != undefined) {
+          throw new TypeError(
+            "Unexpected 'fn' field in options, bench function is already provided as the third argument.",
+          );
+        }
+        if (optionsOrFn.name != undefined) {
+          throw new TypeError(
+            "Unexpected 'name' field in options, bench name is already provided as the first argument.",
+          );
+        }
+        benchDef = {
+          ...defaults,
+          ...optionsOrFn,
+          fn: maybeFn,
+          name: nameOrFnOrOptions,
+        };
+      }
+    } else if (typeof nameOrFnOrOptions === "function") {
+      if (!nameOrFnOrOptions.name) {
+        throw new TypeError("The bench function must have a name");
+      }
+      if (optionsOrFn != undefined) {
+        throw new TypeError("Unexpected second argument to Deno.bench()");
+      }
+      if (maybeFn != undefined) {
+        throw new TypeError("Unexpected third argument to Deno.bench()");
+      }
+      benchDef = {
+        ...defaults,
+        fn: nameOrFnOrOptions,
+        name: nameOrFnOrOptions.name,
+      };
+    } else {
+      let fn;
+      let name;
+      if (typeof optionsOrFn === "function") {
+        fn = optionsOrFn;
+        if (nameOrFnOrOptions.fn != undefined) {
+          throw new TypeError(
+            "Unexpected 'fn' field in options, bench function is already provided as the second argument.",
+          );
+        }
+        name = nameOrFnOrOptions.name ?? fn.name;
+      } else {
+        if (
+          !nameOrFnOrOptions.fn || typeof nameOrFnOrOptions.fn !== "function"
+        ) {
+          throw new TypeError(
+            "Expected 'fn' field in the first argument to be a bench function.",
+          );
+        }
+        fn = nameOrFnOrOptions.fn;
+        name = nameOrFnOrOptions.name ?? fn.name;
+      }
+      if (!name) {
+        throw new TypeError("The bench name can't be empty");
+      }
+      benchDef = { ...defaults, ...nameOrFnOrOptions, fn, name };
+    }
+
+    benchDef.fn = wrapBenchFnWithSanitizers(
+      reportBenchIteration(benchDef.fn),
+      benchDef,
+    );
+
+    if (benchDef.permissions) {
+      benchDef.fn = withPermissions(
+        benchDef.fn,
+        benchDef.permissions,
+      );
+    }
+
+    ArrayPrototypePush(benches, benchDef);
+  }
+
   function formatError(error) {
     if (ObjectPrototypeIsPrototypeOf(AggregateErrorPrototype, error)) {
       const message = error
@@ -699,10 +803,48 @@
     }
   }
 
+  async function runBench(bench) {
+    if (bench.ignore) {
+      return "ignored";
+    }
+
+    const step = new BenchStep({
+      name: bench.name,
+      sanitizeExit: bench.sanitizeExit,
+      warmup: false,
+    });
+
+    try {
+      const warmupIterations = bench.warmupIterations;
+      step.warmup = true;
+
+      for (let i = 0; i < warmupIterations; i++) {
+        await bench.fn(step);
+      }
+
+      const iterations = bench.n;
+      step.warmup = false;
+
+      for (let i = 0; i < iterations; i++) {
+        await bench.fn(step);
+      }
+
+      return "ok";
+    } catch (error) {
+      return {
+        "failed": formatError(error),
+      };
+    }
+  }
+
   function getTestOrigin() {
     return core.opSync("op_get_test_origin");
   }
 
+  function getBenchOrigin() {
+    return core.opSync("op_get_bench_origin");
+  }
+
   function reportTestPlan(plan) {
     core.opSync("op_dispatch_test_event", {
       plan,
@@ -739,6 +881,53 @@
     });
   }
 
+  function reportBenchPlan(plan) {
+    core.opSync("op_dispatch_bench_event", {
+      plan,
+    });
+  }
+
+  function reportBenchConsoleOutput(console) {
+    core.opSync("op_dispatch_bench_event", {
+      output: { console },
+    });
+  }
+
+  function reportBenchWait(description) {
+    core.opSync("op_dispatch_bench_event", {
+      wait: description,
+    });
+  }
+
+  function reportBenchResult(description, result, elapsed) {
+    core.opSync("op_dispatch_bench_event", {
+      result: [description, result, elapsed],
+    });
+  }
+
+  function reportBenchIteration(fn) {
+    return async function benchIteration(step) {
+      let now;
+      if (!step.warmup) {
+        now = benchNow();
+      }
+      await fn(step);
+      if (!step.warmup) {
+        reportIterationTime(benchNow() - now);
+      }
+    };
+  }
+
+  function benchNow() {
+    return core.opSync("op_bench_now");
+  }
+
+  function reportIterationTime(time) {
+    core.opSync("op_dispatch_bench_event", {
+      iterationTime: time,
+    });
+  }
+
   async function runTests({
     filter = null,
     shuffle = null,
@@ -799,6 +988,53 @@
     globalThis.console = originalConsole;
   }
 
+  async function runBenchmarks({
+    filter = null,
+  } = {}) {
+    core.setMacrotaskCallback(handleOpSanitizerDelayMacrotask);
+
+    const origin = getBenchOrigin();
+    const originalConsole = globalThis.console;
+
+    globalThis.console = new Console(reportBenchConsoleOutput);
+
+    const only = ArrayPrototypeFilter(benches, (bench) => bench.only);
+    const filtered = ArrayPrototypeFilter(
+      only.length > 0 ? only : benches,
+      createTestFilter(filter),
+    );
+
+    reportBenchPlan({
+      origin,
+      total: filtered.length,
+      filteredOut: benches.length - filtered.length,
+      usedOnly: only.length > 0,
+    });
+
+    for (const bench of filtered) {
+      // TODO(bartlomieju): probably needs some validation?
+      const iterations = bench.n ?? 1000;
+      const warmupIterations = bench.warmup ?? 1000;
+      const description = {
+        origin,
+        name: bench.name,
+        iterations,
+      };
+      bench.n = iterations;
+      bench.warmupIterations = warmupIterations;
+      const earlier = DateNow();
+
+      reportBenchWait(description);
+
+      const result = await runBench(bench);
+      const elapsed = DateNow() - earlier;
+
+      reportBenchResult(description, result, elapsed);
+    }
+
+    globalThis.console = originalConsole;
+  }
+
   /**
    * @typedef {{
    *   fn: (t: TestContext) => void | Promise<void>,
@@ -989,6 +1225,27 @@
     }
   }
 
+  /**
+   * @typedef {{
+   *   name: string;
+   *   sanitizeExit: boolean,
+   *   warmup: boolean,
+   * }} BenchStepParams
+   */
+  class BenchStep {
+    /** @type {BenchStepParams} */
+    #params;
+
+    /** @param params {BenchStepParams} */
+    constructor(params) {
+      this.#params = params;
+    }
+
+    get name() {
+      return this.#params.name;
+    }
+  }
+
   /** @param parentStep {TestStep} */
   function createTestContext(parentStep) {
     return {
@@ -1121,11 +1378,26 @@
       testFn = assertResources(testFn);
     }
     if (opts.sanitizeExit) {
-      testFn = assertExit(testFn);
+      testFn = assertExit(testFn, true);
     }
     return testFn;
   }
 
+  /**
+   * @template T {Function}
+   * @param fn {T}
+   * @param opts {{
+   *   sanitizeExit: boolean,
+   * }}
+   * @returns {T}
+   */
+  function wrapBenchFnWithSanitizers(fn, opts) {
+    if (opts.sanitizeExit) {
+      fn = assertExit(fn, false);
+    }
+    return fn;
+  }
+
   /**
    * @template T
    * @param value {T | undefined}
@@ -1139,9 +1411,11 @@
   window.__bootstrap.internals = {
     ...window.__bootstrap.internals ?? {},
     runTests,
+    runBenchmarks,
   };
 
   window.__bootstrap.testing = {
     test,
+    bench,
   };
 })(this);

runtime/js/90_deno_ns.js

@@ -7,6 +7,7 @@
   __bootstrap.denoNs = {
     metrics: core.metrics,
     test: __bootstrap.testing.test,
+    bench: __bootstrap.testing.bench,
     Process: __bootstrap.process.Process,
     run: __bootstrap.process.run,
     isatty: __bootstrap.tty.isatty,