Refactor CLI flag parsing (#2025)

49 files changed, 328 insertions, 245 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 5b478ca8f..312915d70 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -215,7 +215,6 @@ dependencies = [
  "dirs 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "flatbuffers 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
- "getopts 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "http 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.12.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper-rustls 0.16.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -318,14 +317,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "getopts"
-version = "0.2.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "unicode-width 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
 name = "h2"
 version = "0.1.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1440,7 +1431,6 @@ dependencies = [
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)" = "49e7653e374fe0d0c12de4250f0bdb60680b8c80eed558c5c7538eec9c89e21b"
 "checksum futures-cpupool 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "ab90cde24b3319636588d0c35fe03b1333857621051837ed769faefb4c2162e4"
-"checksum getopts 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)" = "0a7292d30132fb5424b354f5dc02512a86e4c516fe544bb7a25e7f266951b797"
 "checksum h2 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)" = "910a5e7be6283a9c91b3982fa5188368c8719cce2a3cf3b86048673bf9d9c36b"
 "checksum http 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)" = "fe67e3678f2827030e89cc4b9e7ecd16d52f132c0b940ab5005f88e821500f6a"
 "checksum httparse 1.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e8734b0cfd3bc3e101ec59100e101c2eecd19282202e87808b3037b442777a83"
diff --git a/cli/BUILD.gn b/cli/BUILD.gn
index ffc13891c..ee032a757 100644
--- a/cli/BUILD.gn
+++ b/cli/BUILD.gn
@@ -16,7 +16,6 @@ main_extern = [
   "$rust_build:dirs",
   "$rust_build:flatbuffers",
   "$rust_build:futures",
-  "$rust_build:getopts",
   "$rust_build:http",
   "$rust_build:hyper",
   "$rust_build:hyper_rustls",
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index f1b70b7a6..9bebe84be 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -24,7 +24,6 @@ clap = "2.32.0"
 dirs = "1.0.5"
 flatbuffers = "0.5.0"
 futures = "0.1.25"
-getopts = "0.2.18"
 http = "0.1.16"
 hyper = "0.12.25"
 hyper-rustls = "0.16.1"
diff --git a/cli/flags.rs b/cli/flags.rs
index 9d187ecac..cf1bb72bc 100644
--- a/cli/flags.rs
+++ b/cli/flags.rs
@@ -1,7 +1,6 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+use clap::{App, AppSettings, Arg, ArgMatches, SubCommand};
 use deno::v8_set_flags;
-use getopts;
-use getopts::Options;
 
 // Creates vector of strings, Vec<String>
 #[cfg(test)]
@@ -12,7 +11,6 @@ macro_rules! svec {
 #[cfg_attr(feature = "cargo-clippy", allow(stutter))]
 #[derive(Clone, Debug, PartialEq, Default)]
 pub struct DenoFlags {
-  pub help: bool,
   pub log_debug: bool,
   pub version: bool,
   pub reload: bool,
@@ -28,16 +26,6 @@ pub struct DenoFlags {
   pub fmt: bool,
 }
 
-pub fn get_usage(opts: &Options) -> String {
-  format!(
-    "Usage: deno script.ts {}
-Environment variables:
-        DENO_DIR        Set deno's base directory
-        NO_COLOR        Set to disable color",
-    opts.usage("")
-  )
-}
-
 /// Checks provided arguments for known options and sets appropriate Deno flags
 /// for them. Unknown options are returned for further use.
 /// Note:
@@ -51,129 +39,217 @@ Environment variables:
 /// not cause an error. I also think this is ok because missing any of the
 /// privileged flags is not destructive. Userland flag parsing would catch these
 /// errors.
-fn set_recognized_flags(
-  opts: &Options,
-  flags: &mut DenoFlags,
-  args: Vec<String>,
-) -> Result<Vec<String>, getopts::Fail> {
-  let mut rest = Vec::<String>::new();
-  // getopts doesn't allow parsing unknown options so we check them
-  // one-by-one and handle unrecognized ones manually
-  // better solution welcome!
-  for arg in args {
-    let fake_args = vec![arg];
-    match opts.parse(&fake_args) {
-      Err(getopts::Fail::UnrecognizedOption(_)) => {
-        rest.extend(fake_args);
-      }
-      Err(e) => {
-        return Err(e);
-      }
-      Ok(matches) => {
-        if matches.opt_present("help") {
-          flags.help = true;
-        }
-        if matches.opt_present("log-debug") {
-          flags.log_debug = true;
-        }
-        if matches.opt_present("version") {
-          flags.version = true;
-        }
-        if matches.opt_present("reload") {
-          flags.reload = true;
-        }
-        if matches.opt_present("allow-read") {
-          flags.allow_read = true;
-        }
-        if matches.opt_present("allow-write") {
-          flags.allow_write = true;
-        }
-        if matches.opt_present("allow-net") {
-          flags.allow_net = true;
-        }
-        if matches.opt_present("allow-env") {
-          flags.allow_env = true;
-        }
-        if matches.opt_present("allow-run") {
-          flags.allow_run = true;
-        }
-        if matches.opt_present("allow-all") {
-          flags.allow_read = true;
-          flags.allow_env = true;
-          flags.allow_net = true;
-          flags.allow_run = true;
-          flags.allow_read = true;
-          flags.allow_write = true;
-        }
-        if matches.opt_present("no-prompt") {
-          flags.no_prompts = true;
-        }
-        if matches.opt_present("types") {
-          flags.types = true;
-        }
-        if matches.opt_present("prefetch") {
-          flags.prefetch = true;
-        }
-        if matches.opt_present("info") {
-          flags.info = true;
-        }
-        if matches.opt_present("fmt") {
-          flags.fmt = true;
-        }
-
-        if !matches.free.is_empty() {
-          rest.extend(matches.free);
-        }
-      }
-    }
+fn set_recognized_flags(matches: ArgMatches, flags: &mut DenoFlags) {
+  if matches.is_present("log-debug") {
+    flags.log_debug = true;
+  }
+  if matches.is_present("version") {
+    flags.version = true;
+  }
+  if matches.is_present("reload") {
+    flags.reload = true;
+  }
+  if matches.is_present("allow-read") {
+    flags.allow_read = true;
+  }
+  if matches.is_present("allow-write") {
+    flags.allow_write = true;
+  }
+  if matches.is_present("allow-net") {
+    flags.allow_net = true;
+  }
+  if matches.is_present("allow-env") {
+    flags.allow_env = true;
+  }
+  if matches.is_present("allow-run") {
+    flags.allow_run = true;
+  }
+  if matches.is_present("allow-all") {
+    flags.allow_read = true;
+    flags.allow_env = true;
+    flags.allow_net = true;
+    flags.allow_run = true;
+    flags.allow_read = true;
+    flags.allow_write = true;
+  }
+  if matches.is_present("no-prompt") {
+    flags.no_prompts = true;
+  }
+  if matches.is_present("types") {
+    flags.types = true;
+  }
+  if matches.is_present("prefetch") {
+    flags.prefetch = true;
+  }
+  if matches.is_present("info") {
+    flags.info = true;
+  }
+  if matches.is_present("fmt") {
+    flags.fmt = true;
   }
-  Ok(rest)
 }
 
 #[cfg_attr(feature = "cargo-clippy", allow(stutter))]
 pub fn set_flags(
   args: Vec<String>,
-) -> Result<(DenoFlags, Vec<String>, String), String> {
-  // TODO: all flags passed after "--" are swallowed by v8_set_flags
-  // eg. deno --allow-net ./test.ts -- --title foobar
-  // args === ["deno", "--allow-net" "./test.ts"]
-  let args = v8_set_flags(args);
+) -> Result<(DenoFlags, Vec<String>), String> {
+  let app_settings: Vec<AppSettings> = vec![
+    AppSettings::AllowExternalSubcommands,
+    AppSettings::DisableHelpSubcommand,
+  ];
 
-  let mut opts = Options::new();
-  // TODO(kevinkassimo): v8_set_flags intercepts '-help' with single '-'
-  // Resolve that and then uncomment line below (enabling Go style -long-flag)
-  // opts.long_only(true);
-  opts.optflag("", "allow-read", "Allow file system read access");
-  opts.optflag("", "allow-write", "Allow file system write access");
-  opts.optflag("", "allow-net", "Allow network access");
-  opts.optflag("", "allow-env", "Allow environment access");
-  opts.optflag("", "allow-run", "Allow running subprocesses");
-  opts.optflag("A", "allow-all", "Allow all permissions");
-  opts.optflag("", "no-prompt", "Do not use prompts");
-  opts.optflag("h", "help", "Print this message");
-  opts.optflag("D", "log-debug", "Log debug output");
-  opts.optflag("v", "version", "Print the version");
-  opts.optflag(
-    "r",
-    "reload",
-    "Reload source code cache (recompile TypeScript)",
-  );
-  opts.optflag("", "v8-options", "Print V8 command line options");
-  opts.optflag("", "types", "Print runtime TypeScript declarations");
-  opts.optflag("", "prefetch", "Prefetch the dependencies");
-  opts.optflag("", "info", "Show source file related info");
-  opts.optflag("", "fmt", "Format code");
+  let env_variables_help = "ENVIRONMENT VARIABLES:
+    DENO_DIR        Set deno's base directory
+    NO_COLOR        Set to disable color";
 
-  let mut flags = DenoFlags::default();
+  let clap_app = App::new("deno")
+    .global_settings(&vec![AppSettings::ColorNever])
+    .settings(&app_settings[..])
+    .after_help(env_variables_help)
+    .arg(
+      Arg::with_name("version")
+        .short("v")
+        .long("version")
+        .help("Print the version"),
+    ).arg(
+      Arg::with_name("allow-read")
+        .long("allow-read")
+        .help("Allow file system read access"),
+    ).arg(
+      Arg::with_name("allow-write")
+        .long("allow-write")
+        .help("Allow file system write access"),
+    ).arg(
+      Arg::with_name("allow-net")
+        .long("allow-net")
+        .help("Allow network access"),
+    ).arg(
+      Arg::with_name("allow-env")
+        .long("allow-env")
+        .help("Allow environment access"),
+    ).arg(
+      Arg::with_name("allow-run")
+        .long("allow-run")
+        .help("Allow running subprocesses"),
+    ).arg(
+      Arg::with_name("allow-all")
+        .short("A")
+        .long("allow-all")
+        .help("Allow all permissions"),
+    ).arg(
+      Arg::with_name("no-prompt")
+        .long("no-prompt")
+        .help("Do not use prompts"),
+    ).arg(
+      Arg::with_name("log-debug")
+        .short("D")
+        .long("log-debug")
+        .help("Log debug output"),
+    ).arg(
+      Arg::with_name("reload")
+        .short("r")
+        .long("reload")
+        .help("Reload source code cache (recompile TypeScript)"),
+    ).arg(
+      Arg::with_name("v8-options")
+        .long("v8-options")
+        .help("Print V8 command line options"),
+    ).arg(
+      Arg::with_name("v8-flags")
+        .long("v8-flags")
+        .takes_value(true)
+        .require_equals(true)
+        .help("Set V8 command line options"),
+    ).arg(
+      Arg::with_name("types")
+        .long("types")
+        .help("Print runtime TypeScript declarations"),
+    ).arg(
+      Arg::with_name("prefetch")
+        .long("prefetch")
+        .help("Prefetch the dependencies"),
+    ).subcommand(
+      // TODO(bartlomieju): version is not handled properly
+      SubCommand::with_name("info")
+        .about("Show source file related info")
+        .arg(Arg::with_name("file").takes_value(true).required(true)),
+    ).subcommand(
+      // TODO(bartlomieju): version is not handled properly
+      SubCommand::with_name("fmt").about("Format files").arg(
+        Arg::with_name("files")
+          .takes_value(true)
+          .multiple(true)
+          .required(true),
+      ),
+    ).subcommand(
+      // this is a fake subcommand - it's used in conjunction with
+      // AppSettings:AllowExternalSubcommand to treat it as an
+      // entry point script
+      SubCommand::with_name("<script>").about("Script to run"),
+    );
 
-  let rest =
-    set_recognized_flags(&opts, &mut flags, args).map_err(|e| e.to_string())?;
-  Ok((flags, rest, get_usage(&opts)))
+  let matches = clap_app.get_matches_from(args);
+
+  // TODO(bartomieju): compatibility with old "opts" approach - to be refactored
+  let mut rest: Vec<String> = vec![String::from("deno")];
+
+  match matches.subcommand() {
+    ("info", Some(info_match)) => {
+      // TODO(bartlomieju): it still relies on `is_present("info")` check
+      // in `set_recognized_flags`
+      let file: &str = info_match.value_of("file").unwrap();
+      rest.extend(vec![file.to_string()]);
+    }
+    ("fmt", Some(fmt_match)) => {
+      // TODO(bartlomieju): it still relies on `is_present("fmt")` check
+      // in `set_recognized_flags`
+      let files: Vec<String> = fmt_match
+        .values_of("files")
+        .unwrap()
+        .map(String::from)
+        .collect();
+      rest.extend(files);
+    }
+    (script, Some(script_match)) => {
+      rest.extend(vec![script.to_string()]);
+      // check if there are any extra arguments
+      if script_match.is_present("") {
+        let script_args: Vec<String> = script_match
+          .values_of("")
+          .unwrap()
+          .map(String::from)
+          .collect();
+        rest.extend(script_args);
+      }
+    }
+    _ => {}
+  }
+  // TODO: end
+
+  if matches.is_present("v8-options") {
+    // display v8 help and exit
+    v8_set_flags(vec!["deno".to_string(), "--help".to_string()]);
+  }
+
+  if matches.is_present("v8-flags") {
+    let mut v8_flags: Vec<String> = matches
+      .values_of("v8-flags")
+      .unwrap()
+      .map(String::from)
+      .collect();
+
+    v8_flags.insert(1, "deno".to_string());
+    v8_set_flags(v8_flags);
+  }
+
+  let mut flags = DenoFlags::default();
+  set_recognized_flags(matches, &mut flags);
+  Ok((flags, rest))
 }
 
 #[test]
 fn test_set_flags_1() {
-  let (flags, rest, _) = set_flags(svec!["deno", "--version"]).unwrap();
+  let (flags, rest) = set_flags(svec!["deno", "--version"]).unwrap();
   assert_eq!(rest, svec!["deno"]);
   assert_eq!(
     flags,
@@ -186,7 +262,7 @@ fn test_set_flags_1() {
 
 #[test]
 fn test_set_flags_2() {
-  let (flags, rest, _) =
+  let (flags, rest) =
     set_flags(svec!["deno", "-r", "-D", "script.ts"]).unwrap();
   assert_eq!(rest, svec!["deno", "script.ts"]);
   assert_eq!(
@@ -201,8 +277,8 @@ fn test_set_flags_2() {
 
 #[test]
 fn test_set_flags_3() {
-  let (flags, rest, _) =
-    set_flags(svec!["deno", "-r", "script.ts", "--allow-write"]).unwrap();
+  let (flags, rest) =
+    set_flags(svec!["deno", "-r", "--allow-write", "script.ts"]).unwrap();
   assert_eq!(rest, svec!["deno", "script.ts"]);
   assert_eq!(
     flags,
@@ -216,8 +292,8 @@ fn test_set_flags_3() {
 
 #[test]
 fn test_set_flags_4() {
-  let (flags, rest, _) =
-    set_flags(svec!["deno", "-Dr", "script.ts", "--allow-write"]).unwrap();
+  let (flags, rest) =
+    set_flags(svec!["deno", "-Dr", "--allow-write", "script.ts"]).unwrap();
   assert_eq!(rest, svec!["deno", "script.ts"]);
   assert_eq!(
     flags,
@@ -232,7 +308,7 @@ fn test_set_flags_4() {
 
 #[test]
 fn test_set_flags_5() {
-  let (flags, rest, _) = set_flags(svec!["deno", "--types"]).unwrap();
+  let (flags, rest) = set_flags(svec!["deno", "--types"]).unwrap();
   assert_eq!(rest, svec!["deno"]);
   assert_eq!(
     flags,
@@ -245,8 +321,8 @@ fn test_set_flags_5() {
 
 #[test]
 fn test_set_flags_6() {
-  let (flags, rest, _) =
-    set_flags(svec!["deno", "gist.ts", "--title", "X", "--allow-net"]).unwrap();
+  let (flags, rest) =
+    set_flags(svec!["deno", "--allow-net", "gist.ts", "--title", "X"]).unwrap();
   assert_eq!(rest, svec!["deno", "gist.ts", "--title", "X"]);
   assert_eq!(
     flags,
@@ -259,8 +335,8 @@ fn test_set_flags_6() {
 
 #[test]
 fn test_set_flags_7() {
-  let (flags, rest, _) =
-    set_flags(svec!["deno", "gist.ts", "--allow-all"]).unwrap();
+  let (flags, rest) =
+    set_flags(svec!["deno", "--allow-all", "gist.ts"]).unwrap();
   assert_eq!(rest, svec!["deno", "gist.ts"]);
   assert_eq!(
     flags,
@@ -277,8 +353,8 @@ fn test_set_flags_7() {
 
 #[test]
 fn test_set_flags_8() {
-  let (flags, rest, _) =
-    set_flags(svec!["deno", "gist.ts", "--allow-read"]).unwrap();
+  let (flags, rest) =
+    set_flags(svec!["deno", "--allow-read", "gist.ts"]).unwrap();
   assert_eq!(rest, svec!["deno", "gist.ts"]);
   assert_eq!(
     flags,
diff --git a/cli/isolate.rs b/cli/isolate.rs
index 5fd3e98f9..1d7201074 100644
--- a/cli/isolate.rs
+++ b/cli/isolate.rs
@@ -265,7 +265,7 @@ mod tests {
     let filename = filename.to_str().unwrap().to_string();
 
     let argv = vec![String::from("./deno"), filename.clone()];
-    let (flags, rest_argv, _) = flags::set_flags(argv).unwrap();
+    let (flags, rest_argv) = flags::set_flags(argv).unwrap();
 
     let state = Arc::new(IsolateState::new(flags, rest_argv, None, false));
     let state_ = state.clone();
@@ -288,7 +288,7 @@ mod tests {
     let filename = filename.to_str().unwrap().to_string();
 
     let argv = vec![String::from("./deno"), filename.clone()];
-    let (flags, rest_argv, _) = flags::set_flags(argv).unwrap();
+    let (flags, rest_argv) = flags::set_flags(argv).unwrap();
 
     let state = Arc::new(IsolateState::new(flags, rest_argv, None, false));
     let state_ = state.clone();
diff --git a/cli/isolate_state.rs b/cli/isolate_state.rs
index b0fb97f10..500cdd7d7 100644
--- a/cli/isolate_state.rs
+++ b/cli/isolate_state.rs
@@ -122,7 +122,7 @@ impl IsolateState {
   pub fn mock() -> IsolateState {
     let argv = vec![String::from("./deno"), String::from("hello.js")];
     // For debugging: argv.push_back(String::from("-D"));
-    let (flags, rest_argv, _) = flags::set_flags(argv).unwrap();
+    let (flags, rest_argv) = flags::set_flags(argv).unwrap();
     IsolateState::new(flags, rest_argv, None, false)
   }
 
diff --git a/cli/main.rs b/cli/main.rs
index f9a88803e..4d0ceab5a 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -7,6 +7,8 @@ extern crate log;
 extern crate futures;
 #[macro_use]
 extern crate serde_json;
+extern crate clap;
+extern crate deno;
 
 mod ansi;
 pub mod cli_behavior;
@@ -82,17 +84,12 @@ fn main() {
 
   log::set_logger(&LOGGER).unwrap();
   let args = env::args().collect();
-  let (mut flags, mut rest_argv, usage_string) = flags::set_flags(args)
-    .unwrap_or_else(|err| {
+  let (mut flags, mut rest_argv) =
+    flags::set_flags(args).unwrap_or_else(|err| {
       eprintln!("{}", err);
       std::process::exit(1)
     });
 
-  if flags.help {
-    println!("{}", &usage_string);
-    std::process::exit(0);
-  }
-
   log::set_max_level(if flags.log_debug {
     LevelFilter::Debug
   } else {
diff --git a/tests/001_hello.test b/tests/001_hello.test
index 1e37d024d..121dbb2ea 100644
--- a/tests/001_hello.test
+++ b/tests/001_hello.test
@@ -1,2 +1,2 @@
-args: tests/001_hello.js --reload
+args: --reload tests/001_hello.js
 output: tests/001_hello.js.out
diff --git a/tests/002_hello.test b/tests/002_hello.test
index 881271a97..d889acd00 100644
--- a/tests/002_hello.test
+++ b/tests/002_hello.test
@@ -1,2 +1,2 @@
-args: tests/002_hello.ts --reload
+args: --reload tests/002_hello.ts
 output: tests/002_hello.ts.out
diff --git a/tests/003_relative_import.test b/tests/003_relative_import.test
index 42336ba22..5206c1aaa 100644
--- a/tests/003_relative_import.test
+++ b/tests/003_relative_import.test
@@ -1,2 +1,2 @@
-args: tests/003_relative_import.ts --reload
+args: --reload tests/003_relative_import.ts
 output: tests/003_relative_import.ts.out
diff --git a/tests/004_set_timeout.test b/tests/004_set_timeout.test
index ea47ef1f3..6fda34f25 100644
--- a/tests/004_set_timeout.test
+++ b/tests/004_set_timeout.test
@@ -1,2 +1,2 @@
-args: tests/004_set_timeout.ts --reload
+args: --reload tests/004_set_timeout.ts
 output: tests/004_set_timeout.ts.out
diff --git a/tests/005_more_imports.test b/tests/005_more_imports.test
index 998047a7b..fde5276fe 100644
--- a/tests/005_more_imports.test
+++ b/tests/005_more_imports.test
@@ -1,2 +1,2 @@
-args: tests/005_more_imports.ts --reload
+args: --reload tests/005_more_imports.ts
 output: tests/005_more_imports.ts.out
diff --git a/tests/006_url_imports.test b/tests/006_url_imports.test
index c7210c83c..13c04219a 100644
--- a/tests/006_url_imports.test
+++ b/tests/006_url_imports.test
@@ -1,2 +1,2 @@
-args: tests/006_url_imports.ts --reload
+args: --reload tests/006_url_imports.ts
 output: tests/006_url_imports.ts.out
diff --git a/tests/010_set_interval.test b/tests/010_set_interval.test
index f7c7a1f00..08ef3d36c 100644
--- a/tests/010_set_interval.test
+++ b/tests/010_set_interval.test
@@ -1,2 +1,2 @@
-args: tests/010_set_interval.ts --reload
+args: --reload tests/010_set_interval.ts
 output: tests/010_set_interval.ts.out
diff --git a/tests/012_async.test b/tests/012_async.test
index 7bfe0a3c5..3694d7362 100644
--- a/tests/012_async.test
+++ b/tests/012_async.test
@@ -1,2 +1,2 @@
-args: tests/012_async.ts --reload
+args: --reload tests/012_async.ts
 output: tests/012_async.ts.out
diff --git a/tests/016_double_await.test b/tests/016_double_await.test
index 35c028810..842d167cc 100644
--- a/tests/016_double_await.test
+++ b/tests/016_double_await.test
@@ -1,2 +1,2 @@
-args: tests/016_double_await.ts --allow-read --reload
+args: --allow-read --reload tests/016_double_await.ts
 output: tests/016_double_await.ts.out
diff --git a/tests/017_import_redirect.test b/tests/017_import_redirect.test
index 4550a2f76..db7439f05 100644
--- a/tests/017_import_redirect.test
+++ b/tests/017_import_redirect.test
@@ -1,2 +1,2 @@
-args: tests/017_import_redirect.ts --reload
+args: --reload tests/017_import_redirect.ts
 output: tests/017_import_redirect.ts.out
diff --git a/tests/018_async_catch.test b/tests/018_async_catch.test
index 582ff2b35..08961916d 100644
--- a/tests/018_async_catch.test
+++ b/tests/018_async_catch.test
@@ -1,2 +1,2 @@
-args: tests/018_async_catch.ts --reload
+args: --reload tests/018_async_catch.ts
 output: tests/018_async_catch.ts.out
diff --git a/tests/019_media_types.test b/tests/019_media_types.test
index 28b14e641..c0fea5bc6 100644
--- a/tests/019_media_types.test
+++ b/tests/019_media_types.test
@@ -1,2 +1,2 @@
-args: tests/019_media_types.ts --reload
+args: --reload tests/019_media_types.ts
 output: tests/019_media_types.ts.out
diff --git a/tests/020_json_modules.test b/tests/020_json_modules.test
index d9e9467fa..cacd21da0 100644
--- a/tests/020_json_modules.test
+++ b/tests/020_json_modules.test
@@ -1,2 +1,2 @@
-args: tests/020_json_modules.ts --reload
+args: --reload tests/020_json_modules.ts
 output: tests/020_json_modules.ts.out
diff --git a/tests/022_info_flag.test b/tests/022_info_flag.test
index 2de27bdfa..e58288ec5 100644
--- a/tests/022_info_flag.test
+++ b/tests/022_info_flag.test
@@ -1,4 +1,4 @@
 # The output assumes 003_relative_import.ts has already been run earlier
 # and its output is cached to $DENO_DIR.
-args: --info http://127.0.0.1:4545/tests/019_media_types.ts
+args: info http://127.0.0.1:4545/tests/019_media_types.ts
 output: tests/022_info_flag.out
diff --git a/tests/023_no_ext_with_headers.test b/tests/023_no_ext_with_headers.test
index 5be189af0..b663f174c 100644
--- a/tests/023_no_ext_with_headers.test
+++ b/tests/023_no_ext_with_headers.test
@@ -1,2 +1,2 @@
-args: tests/023_no_ext_with_headers --reload
+args: --reload tests/023_no_ext_with_headers
 output: tests/023_no_ext_with_headers.out
diff --git a/tests/024_import_no_ext_with_headers.test b/tests/024_import_no_ext_with_headers.test
index 572158f12..efaca96c3 100644
--- a/tests/024_import_no_ext_with_headers.test
+++ b/tests/024_import_no_ext_with_headers.test
@@ -1,2 +1,2 @@
-args: tests/024_import_no_ext_with_headers.ts --reload
+args: --reload tests/024_import_no_ext_with_headers.ts
 output: tests/024_import_no_ext_with_headers.ts.out
diff --git a/tests/025_reload_js_type_error.test b/tests/025_reload_js_type_error.test
index de8c6e51d..a2cd214be 100644
--- a/tests/025_reload_js_type_error.test
+++ b/tests/025_reload_js_type_error.test
@@ -1,2 +1,2 @@
-args: tests/025_reload_js_type_error.js --reload
+args: --reload tests/025_reload_js_type_error.js
 output: tests/025_reload_js_type_error.js.out
diff --git a/tests/026_redirect_javascript.js.test b/tests/026_redirect_javascript.js.test
index a66cb0ea0..81d0ad038 100644
--- a/tests/026_redirect_javascript.js.test
+++ b/tests/026_redirect_javascript.js.test
@@ -1,2 +1,2 @@
-args: tests/026_redirect_javascript.js --reload
+args: --reload tests/026_redirect_javascript.js
 output: tests/026_redirect_javascript.js.out
diff --git a/tests/026_workers.test b/tests/026_workers.test
index 1c5b6f4e6..5019a9256 100644
--- a/tests/026_workers.test
+++ b/tests/026_workers.test
@@ -1,2 +1,2 @@
-args: tests/026_workers.ts --reload
-output: tests/026_workers.ts.out
\ No newline at end of file
+args: --reload tests/026_workers.ts
+output: tests/026_workers.ts.out
diff --git a/tests/027_redirect_typescript.ts.test b/tests/027_redirect_typescript.ts.test
index 8abfbc616..8762e61f2 100644
--- a/tests/027_redirect_typescript.ts.test
+++ b/tests/027_redirect_typescript.ts.test
@@ -1,2 +1,2 @@
-args: tests/027_redirect_typescript.ts --reload
-output: tests/027_redirect_typescript.ts.out
\ No newline at end of file
+args: --reload tests/027_redirect_typescript.ts
+output: tests/027_redirect_typescript.ts.out
diff --git a/tests/028_args.test b/tests/028_args.test
new file mode 100644
index 000000000..df3c56205
--- /dev/null
+++ b/tests/028_args.test
@@ -0,0 +1,2 @@
+args: --reload tests/028_args.ts --arg1 val1 --arg2=val2 -- arg3 arg4
+output: tests/028_args.ts.out
diff --git a/tests/028_args.ts b/tests/028_args.ts
new file mode 100644
index 000000000..15df61555
--- /dev/null
+++ b/tests/028_args.ts
@@ -0,0 +1,3 @@
+Deno.args.forEach(arg => {
+  console.log(arg);
+});
diff --git a/tests/028_args.ts.out b/tests/028_args.ts.out
new file mode 100644
index 000000000..003599c0d
--- /dev/null
+++ b/tests/028_args.ts.out
@@ -0,0 +1,7 @@
+tests/028_args.ts
+--arg1
+val1
+--arg2=val2
+--
+arg3
+arg4
diff --git a/tests/async_error.test b/tests/async_error.test
index 4667f6e09..8ebbfb56c 100644
--- a/tests/async_error.test
+++ b/tests/async_error.test
@@ -1,4 +1,4 @@
 exit_code: 1
-args: tests/async_error.ts --reload
+args: --reload tests/async_error.ts
 check_stderr: true
 output: tests/async_error.ts.out
diff --git a/tests/error_001.test b/tests/error_001.test
index 354f536d5..ca0a2ef2e 100644
--- a/tests/error_001.test
+++ b/tests/error_001.test
@@ -1,4 +1,4 @@
-args: tests/error_001.ts --reload
+args: --reload tests/error_001.ts
 check_stderr: true
 exit_code: 1
 output: tests/error_001.ts.out
diff --git a/tests/error_002.test b/tests/error_002.test
index e8658ad96..12f6e3cec 100644
--- a/tests/error_002.test
+++ b/tests/error_002.test
@@ -1,4 +1,4 @@
-args: tests/error_002.ts --reload
+args: --reload tests/error_002.ts
 check_stderr: true
 exit_code: 1
 output: tests/error_002.ts.out
diff --git a/tests/error_003_typescript.test b/tests/error_003_typescript.test
index cacce54cc..7a9d4a8ea 100644
--- a/tests/error_003_typescript.test
+++ b/tests/error_003_typescript.test
@@ -1,3 +1,3 @@
-args: tests/error_003_typescript.ts --reload
+args: --reload tests/error_003_typescript.ts
 exit_code: 1
 output: tests/error_003_typescript.ts.out
diff --git a/tests/error_007_any.test b/tests/error_007_any.test
index 970049195..fc0480796 100644
--- a/tests/error_007_any.test
+++ b/tests/error_007_any.test
@@ -1,4 +1,4 @@
-args: tests/error_007_any.ts --reload
+args: --reload tests/error_007_any.ts
 check_stderr: true
 exit_code: 1
 output: tests/error_007_any.ts.out
diff --git a/tests/error_008_checkjs.test b/tests/error_008_checkjs.test
index 0e43421e4..1944f0bca 100644
--- a/tests/error_008_checkjs.test
+++ b/tests/error_008_checkjs.test
@@ -1,4 +1,4 @@
-args: tests/error_008_checkjs.js --reload
+args: --reload tests/error_008_checkjs.js
 check_stderr: true
 exit_code: 1
 output: tests/error_008_checkjs.js.out
diff --git a/tests/error_syntax.test b/tests/error_syntax.test
index 297711bfa..e83cd030f 100644
--- a/tests/error_syntax.test
+++ b/tests/error_syntax.test
@@ -1,4 +1,4 @@
-args: tests/error_syntax.js --reload
+args: --reload tests/error_syntax.js
 check_stderr: true
 exit_code: 1
 output: tests/error_syntax.js.out
diff --git a/tests/exit_error42.test b/tests/exit_error42.test
index 59e4cd3d2..21a339a5e 100644
--- a/tests/exit_error42.test
+++ b/tests/exit_error42.test
@@ -1,3 +1,3 @@
 exit_code: 42
-args: tests/exit_error42.ts --reload
+args: --reload tests/exit_error42.ts
 output: tests/exit_error42.ts.out
diff --git a/tests/https_import.test b/tests/https_import.test
index e308466be..6cfb53058 100644
--- a/tests/https_import.test
+++ b/tests/https_import.test
@@ -1,2 +1,2 @@
-args: tests/https_import.ts --reload
+args: --reload tests/https_import.ts
 output: tests/https_import.ts.out
diff --git a/tests/if_main.test b/tests/if_main.test
index 5830d00f8..fe4f061a6 100644
--- a/tests/if_main.test
+++ b/tests/if_main.test
@@ -1,2 +1,2 @@
-args: tests/if_main.ts --reload
+args: --reload tests/if_main.ts
 output: tests/if_main.ts.out
diff --git a/tests/import_meta.test b/tests/import_meta.test
index 6767cfbb2..bfef5cb56 100644
--- a/tests/import_meta.test
+++ b/tests/import_meta.test
@@ -1,2 +1,2 @@
-args: tests/import_meta.ts --reload
+args: --reload tests/import_meta.ts
 output: tests/import_meta.ts.out
diff --git a/tests/unbuffered_stderr.test b/tests/unbuffered_stderr.test
index 0e4109c7f..b3909dc2d 100644
--- a/tests/unbuffered_stderr.test
+++ b/tests/unbuffered_stderr.test
@@ -1,3 +1,3 @@
-args: tests/unbuffered_stderr.ts --reload
+args: --reload tests/unbuffered_stderr.ts
 check_stderr: true
 output: tests/unbuffered_stderr.ts.out
diff --git a/tests/unbuffered_stdout.test b/tests/unbuffered_stdout.test
index d0476b3ac..3ed399cb8 100644
--- a/tests/unbuffered_stdout.test
+++ b/tests/unbuffered_stdout.test
@@ -1,2 +1,2 @@
-args: tests/unbuffered_stdout.ts --reload
+args: --reload tests/unbuffered_stdout.ts
 output: tests/unbuffered_stdout.ts.out
diff --git a/tools/benchmark.py b/tools/benchmark.py
index db2ef0fb2..2e3ac26e4 100755
--- a/tools/benchmark.py
+++ b/tools/benchmark.py
@@ -23,8 +23,8 @@ exec_time_benchmarks = [
     ("hello", ["tests/002_hello.ts"]),
     ("relative_import", ["tests/003_relative_import.ts"]),
     ("error_001", ["tests/error_001.ts"]),
-    ("cold_hello", ["tests/002_hello.ts", "--reload"]),
-    ("cold_relative_import", ["tests/003_relative_import.ts", "--reload"]),
+    ("cold_hello", ["--reload", "tests/002_hello.ts"]),
+    ("cold_relative_import", ["--reload", "tests/003_relative_import.ts"]),
     ("workers_startup", ["tests/workers_startup_bench.ts"]),
     ("workers_round_robin", ["tests/workers_round_robin_bench.ts"]),
 ]
@@ -127,10 +127,10 @@ def get_strace_summary(test_args):
 def run_thread_count_benchmark(deno_path):
     thread_count_map = {}
     thread_count_map["set_timeout"] = get_strace_summary([
-        deno_path, "tests/004_set_timeout.ts", "--reload"
+        deno_path, "--reload", "tests/004_set_timeout.ts"
     ])["clone"]["calls"] + 1
     thread_count_map["fetch_deps"] = get_strace_summary([
-        deno_path, "tests/fetch_deps.ts", "--reload", "--allow-net"
+        deno_path, "--reload", "--allow-net", "tests/fetch_deps.ts"
     ])["clone"]["calls"] + 1
     return thread_count_map
 
@@ -147,10 +147,10 @@ def run_throughput(deno_exe):
 def run_syscall_count_benchmark(deno_path):
     syscall_count_map = {}
     syscall_count_map["hello"] = get_strace_summary(
-        [deno_path, "tests/002_hello.ts", "--reload"])["total"]["calls"]
+        [deno_path, "--reload", "tests/002_hello.ts"])["total"]["calls"]
     syscall_count_map["fetch_deps"] = get_strace_summary(
-        [deno_path, "tests/fetch_deps.ts", "--reload",
-         "--allow-net"])["total"]["calls"]
+        [deno_path, "--reload", "--allow-net",
+         "tests/fetch_deps.ts"])["total"]["calls"]
     return syscall_count_map
 
 
diff --git a/tools/fmt_test.py b/tools/fmt_test.py
index dd704485d..85b475015 100755
--- a/tools/fmt_test.py
+++ b/tools/fmt_test.py
@@ -19,7 +19,7 @@ def fmt_test(deno_exe):
         # Set DENO_DIR to //js/ so we don't have to rely on an intenet
         # connection to download https://deno.land/std/prettier/main.ts
         deno_dir = os.path.join(root_path, "js")
-        run([deno_exe, dst, "--fmt"], merge_env={"DENO_DIR": deno_dir})
+        run([deno_exe, "fmt", dst], merge_env={"DENO_DIR": deno_dir})
         with open(fixed_filename) as f:
             expected = f.read()
         with open(dst) as f:
diff --git a/tools/permission_prompt_test.py b/tools/permission_prompt_test.py
index 312af2cf2..6e8922640 100755
--- a/tools/permission_prompt_test.py
+++ b/tools/permission_prompt_test.py
@@ -69,14 +69,14 @@ class Prompt(object):
         self.deno_exe = deno_exe
         self.test_types = test_types
 
-    def run(self, args, bytes_input):
+    def run(self, flags, args, bytes_input):
         "Returns (return_code, stdout, stderr)."
-        cmd = [self.deno_exe, PERMISSIONS_PROMPT_TEST_TS] + args
+        cmd = [self.deno_exe] + flags + [PERMISSIONS_PROMPT_TEST_TS] + args
         return tty_capture(cmd, bytes_input)
 
     def warm_up(self):
         # ignore the ts compiling message
-        self.run('needsWrite', b'', ["--allow-write"])
+        self.run(["--allow-write"], 'needsWrite', b'')
 
     def test(self):
         for test_type in self.test_types:
@@ -99,14 +99,14 @@ class Prompt(object):
 
     def test_allow_flag(self, test_type):
         code, stdout, stderr = self.run(
-            ["needs" + test_type.capitalize(), "--allow-" + test_type], b'')
+            ["--allow-" + test_type], ["needs" + test_type.capitalize()], b'')
         assert code == 0
         assert not PROMPT_PATTERN in stderr
         assert not FIRST_CHECK_FAILED_PATTERN in stdout
         assert not PERMISSION_DENIED_PATTERN in stderr
 
     def test_yes_yes(self, test_type):
-        code, stdout, stderr = self.run(["needs" + test_type.capitalize()],
+        code, stdout, stderr = self.run([], ["needs" + test_type.capitalize()],
                                         b'y\ny\n')
         assert code == 0
         assert PROMPT_PATTERN in stderr
@@ -114,7 +114,7 @@ class Prompt(object):
         assert not PERMISSION_DENIED_PATTERN in stderr
 
     def test_yes_no(self, test_type):
-        code, stdout, stderr = self.run(["needs" + test_type.capitalize()],
+        code, stdout, stderr = self.run([], ["needs" + test_type.capitalize()],
                                         b'y\nn\n')
         assert code == 1
         assert PROMPT_PATTERN in stderr
@@ -122,7 +122,7 @@ class Prompt(object):
         assert PERMISSION_DENIED_PATTERN in stderr
 
     def test_no_no(self, test_type):
-        code, stdout, stderr = self.run(["needs" + test_type.capitalize()],
+        code, stdout, stderr = self.run([], ["needs" + test_type.capitalize()],
                                         b'n\nn\n')
         assert code == 1
         assert PROMPT_PATTERN in stderr
@@ -130,7 +130,7 @@ class Prompt(object):
         assert PERMISSION_DENIED_PATTERN in stderr
 
     def test_no_yes(self, test_type):
-        code, stdout, stderr = self.run(["needs" + test_type.capitalize()],
+        code, stdout, stderr = self.run([], ["needs" + test_type.capitalize()],
                                         b'n\ny\n')
         assert code == 0
 
@@ -139,7 +139,7 @@ class Prompt(object):
         assert not PERMISSION_DENIED_PATTERN in stderr
 
     def test_allow(self, test_type):
-        code, stdout, stderr = self.run(["needs" + test_type.capitalize()],
+        code, stdout, stderr = self.run([], ["needs" + test_type.capitalize()],
                                         b'a\n')
         assert code == 0
         assert PROMPT_PATTERN in stderr
@@ -147,7 +147,7 @@ class Prompt(object):
         assert not PERMISSION_DENIED_PATTERN in stderr
 
     def test_deny(self, test_type):
-        code, stdout, stderr = self.run(["needs" + test_type.capitalize()],
+        code, stdout, stderr = self.run([], ["needs" + test_type.capitalize()],
                                         b'd\n')
         assert code == 1
         assert PROMPT_PATTERN in stderr
@@ -155,7 +155,7 @@ class Prompt(object):
         assert PERMISSION_DENIED_PATTERN in stderr
 
     def test_unrecognized_option(self, test_type):
-        code, stdout, stderr = self.run(["needs" + test_type.capitalize()],
+        code, stdout, stderr = self.run([], ["needs" + test_type.capitalize()],
                                         b'e\na\n')
         assert code == 0
         assert PROMPT_PATTERN in stderr
@@ -165,17 +165,16 @@ class Prompt(object):
 
     def test_no_prompt(self, test_type):
         code, stdout, stderr = self.run(
-            ["needs" + test_type.capitalize(), "--no-prompt"], b'')
+            ["--no-prompt"], ["needs" + test_type.capitalize()], b'')
         assert code == 1
         assert not PROMPT_PATTERN in stderr
         assert FIRST_CHECK_FAILED_PATTERN in stdout
         assert PERMISSION_DENIED_PATTERN in stderr
 
     def test_no_prompt_allow(self, test_type):
-        code, stdout, stderr = self.run([
-            "needs" + test_type.capitalize(), "--no-prompt",
-            "--allow-" + test_type
-        ], b'')
+        code, stdout, stderr = self.run(
+            ["--no-prompt", "--allow-" + test_type],
+            ["needs" + test_type.capitalize()], b'')
         assert code == 0
         assert not PROMPT_PATTERN in stderr
         assert not FIRST_CHECK_FAILED_PATTERN in stdout
diff --git a/tools/throughput_benchmark.py b/tools/throughput_benchmark.py
index 9048d3582..712edfe43 100755
--- a/tools/throughput_benchmark.py
+++ b/tools/throughput_benchmark.py
@@ -19,7 +19,7 @@ ADDR = "127.0.0.1:4544"
 def cat(deno_exe, megs):
     size = megs * MB
     start = time.time()
-    cmd = deno_exe + " tests/cat.ts --allow-read /dev/zero | head -c %s " % size
+    cmd = deno_exe + " --allow-read tests/cat.ts /dev/zero | head -c %s " % size
     print cmd
     subprocess.check_output(cmd, shell=True)
     end = time.time()
diff --git a/tools/unit_tests.py b/tools/unit_tests.py
index 45b35b417..76ecefbde 100755
--- a/tools/unit_tests.py
+++ b/tools/unit_tests.py
@@ -32,7 +32,7 @@ def run_unit_test2(cmd):
 def run_unit_test(deno_exe, permStr, flags=None):
     if flags is None:
         flags = []
-    cmd = [deno_exe, "js/unit_tests.ts", permStr] + flags
+    cmd = [deno_exe, "js/unit_tests.ts"] + flags + [permStr]
     run_unit_test2(cmd)
 
 
diff --git a/website/manual.md b/website/manual.md
index 7480e25ff..c9609741c 100644
--- a/website/manual.md
+++ b/website/manual.md
@@ -67,10 +67,12 @@ Deno provides <a href="https://github.com/denoland/deno_std">a set of reviewed
 - Be able to serve HTTP efficiently.
   ([Currently it is relatively slow.](https://deno.land/benchmarks.html#req-per-sec))
 
-- Provide useful tooling out of the box: Built-in command-line debugger
-  [not yet](https://github.com/denoland/deno/issues/1120), built-in lint
-  [not yet](https://github.com/denoland/deno/issues/1880), dependency inspector
-  (`deno --info`), built-in code formatter (`deno --fmt`),
+- Provide useful tooling out of the box:
+  - command-line debugger
+    [not yet](https://github.com/denoland/deno/issues/1120)
+  - linter [not yet](https://github.com/denoland/deno/issues/1880)
+  - dependency inspector (`deno info`)
+  - code formatter (`deno fmt`),
 
 ### Non-goals
 
@@ -533,29 +535,38 @@ if (import.meta.main) {
 
 ```shellsession
 $ deno -h
-Usage: deno script.ts
-
-Options:
-        --allow-read    Allow file system read access
-        --allow-write   Allow file system write access
-        --allow-net     Allow network access
-        --allow-env     Allow environment access
-        --allow-run     Allow running subprocesses
-    -A, --allow-all     Allow all permissions
-        --no-prompt     Do not use prompts
-    -h, --help          Print this message
-    -D, --log-debug     Log debug output
-    -v, --version       Print the version
-    -r, --reload        Reload source code cache (recompile TypeScript)
-        --v8-options    Print V8 command line options
-        --types         Print runtime TypeScript declarations
-        --prefetch      Prefetch the dependencies
-        --info          Show source file related info
-        --fmt           Format code
-
-Environment variables:
-        DENO_DIR        Set deno's base directory
-        NO_COLOR        Set to disable color
+deno
+
+USAGE:
+    deno_dev [FLAGS] [OPTIONS] [SUBCOMMAND]
+
+FLAGS:
+    -A, --allow-all      Allow all permissions
+        --allow-env      Allow environment access
+        --allow-net      Allow network access
+        --allow-read     Allow file system read access
+        --allow-run      Allow running subprocesses
+        --allow-write    Allow file system write access
+    -h, --help           Prints help information
+    -D, --log-debug      Log debug output
+        --no-prompt      Do not use prompts
+        --prefetch       Prefetch the dependencies
+    -r, --reload         Reload source code cache (recompile TypeScript)
+        --types          Print runtime TypeScript declarations
+        --v8-options     Print V8 command line options
+    -v, --version        Print the version
+
+OPTIONS:
+        --v8-flags=<v8-flags>    Set V8 command line options
+
+SUBCOMMANDS:
+    <script>    Script to run
+    fmt         Format files
+    info        Show source file related info
+
+ENVIRONMENT VARIABLES:
+    DENO_DIR        Set deno's base directory
+    NO_COLOR        Set to disable color
 ```
 
 ### Environmental variables