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A simple way to replace npm scripts in Deno

Heiker on May 14, 2020

Update 2022-04-13: Since version 1.20 deno now includes a task runner. You can find the details in the release note: new subcommand deno task. F...

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Khaled Bentoumi • May 15 '20

Thanks for the article, I've been also working on a tool to replace npm scripts in Deno.

It uses YAML and currently supports permissions github.com/BentoumiTech/denox/

Heiker • May 15 '20

Looks really good. I see that it can run a selected file with the permissions, but what about random commands? Is there a plan for that?

Ryan • Jun 15 '20

I was able to use the code from this article and the denox package to create a similar npm feel. If you pass your script in as a string then split the script on the spaces to get your arguments it becomes much more usable.

If Khaled added a logical check on the config file to check if a file or script is being provided I'm sure we could achieve the desired outcome.

async function exec(script: String): Promise<any> {
  const args = script.split(' ');
  const proc = await Deno.run({ cmd: args }).status();

  if(proc.success == false) {
    Deno.exit(proc.code);
  }

  return proc;
}

export default exec;

Ryan • Jun 16 '20

github.com/BentoumiTech/denox/pull/15 I took the liberty to add the functionality you're looking for. Denox is a pretty awesome package so hopefully, this gets picked up.

Heiker • Jun 16 '20

That's awesome. But I'm a little bit worried by this right here: const args = script.split(' ');, it doesn't handle quoted arguments. If you give it something like this

some-cli-tool -m "a message" -m "some other message"

You would get.

["some-cli-tool" "-m", "\"a", "message\"", "-m", "\"some", "other", "message\"" ]

Would Deno.run handle that?

Ryan • Jun 17 '20

That's a great observation. Do you have any suggestions on how to handle this case?

Heiker • Jun 17 '20

I found this package: exec. It does the same thing as that function with more options. You could use that. It only handles double quotes but it's an improvement.

If anyone is curious how they do it, here it is.

function splitCommand(command) {
  var myRegexp = /[^\s"]+|"([^"]*)"/gi;
  var splits = [];

  do {
    //Each call to exec returns the next regex match as an array
    var match = myRegexp.exec(command);
    if (match != null) {
      //Index 1 in the array is the captured group if it exists
      //Index 0 is the matched text, which we use if no captured group exists
      splits.push(match[1] ? match[1] : match[0]);
    }
  } while (match != null);

  return splits;
}

Ryan • Jun 17 '20 • Edited

What about double quotes enclosed within single quotes, echo 'And he said: "My name is!" ${name}'. It's a contrived example but you get the gist.

Heiker • Jun 17 '20

For that you would get.

[ "echo", "'And", "he", "said:", "My name is!", "aa'" ]

See, the double quotes stayed, but everything else is broken. Having a bulletproof regex is a real pain. If you want to improve it, you have to modify this var myRegexp = /[^\s"]+|"([^"]*)"/gi;.

Rodion Borisov • Oct 20 '20

AFAIK, they are going to make denox run as alias to denox run default, so it's even faster to type than denox start. Clear and concise IMO!

Rodion Borisov • Nov 21 '20

denon, velociraptor, and trex seem promising. I think that they have more chances to be widespread.

Ryan • Jun 15 '20

I really like the work you've done! It needs an ability to put an "on the fly" script like in package.json

Pacharapol Withayasakpunt • May 15 '20

I think robo is nice. YAML is so much better than JSON, only inferior to real scripts.

Heiker • May 15 '20

It does look nice. I've been using task, it also uses YAML but I think it has more features. But really like how robo handle the arguments for the subcommands.

While on the subject of task runners, a few days ago I saw this one: mask. It uses markdown files to define the options of the subcommands. I haven't use it but it looks really cool.

Kerry Boyko • Mar 18 '21

Hey, I turned Taskfile.js into Taskfile.ts and added some typing info. Let me know what you think.
gist.github.com/brianboyko/735c9d9...

Heiker • Apr 13 '21

It's awesome. May I suggest a "task" to list the other available tasks in the object. I do something like this:

run(Deno.args, {
  start(...args) {
    exec(["deno", "run", entrypoint, ...args]);
  },
  // others tasks....
  list() {
    Object.keys(this).forEach((k) => console.log(k));
  },
});

Nepali Lab • Jul 8 '20

Yeah, so much true. I was learning Deno and the pain of writing flags for each network or dotenv files burns me up. Was looking for a solution. Thank you for the article.

HAMDAOUI Hamza • May 15 '20 • Edited

Thanks for your Article.
Here's a tutorial on how to make an Alias in PowerShell

Heiker • May 15 '20

Thanks.

I've added the alias example on powershell. I hope I got it right.