Task Runner with jbang

[koppor]

On https://www.jbang.dev/documentation/guide/latest/usage.html#running-markdowns-md-experimental, I saw Markdown support.

I stumbled on maid, which is a Markdown-based task runner:

## lint

It uses ESLint to ensure code quality.

```bash
eslint --fix
```

## build

Build our main app

<!-- Following line is a maid command for running task -->

Run task `build:demo` after this

```bash
# note that you can directly call binaries inside node_modules/.bin
# just like how `npm scripts` works
babel src -d lib
```

## build:demo

You can use JavaScript to write to task script too!

```js
const webpack = require('webpack')

// Async task should return a Promise
module.exports = () =>
  new Promise((resolve, reject) => {
    const compiler = webpack(require('./webpack.config'))
    compiler.run((err, stats) => {
      if (err) return reject(err)
      console.log(stats.toString('minimal'))
      resolve()
    })
  })
```

---

Idea:

Can I have the ideas combined?

Multiple (!) jbang-based scripts in a single Markdown file?

Example call:

jbang tasks.md build

Arguments could be passed, too

jbang tasks.md build the-thing

Then, the-thing would be passed to the build script. See https://github.com/egoist/maid#read-command-line-arguments for "details".

---

It's not about re-implementing just completely 😅

[maxandersen]

fun idea - and I could easily see it implemented.

It unfortunately (at least in the current proposed state) breaks the simple rule we have of jbang run following the format:

jbang [run] <options> <scriptRef> <script arguments>

meaning anything after <scriptRef> (i.e. tasks.md) must be taken and passed as arguments to the script - introducing a special case for .md files albeit it being cool feels like an overreach.

If could come up with some other variant I could consider it, jbang tasks <scriptRef> <task syntax> maybe (and not limit it to markdown only) ? or some variant of alias syntax?

jbang --task mytask tasks.md <args> could be a thing and used to filter which part of markdown to honor...

That said - there is a lot of assumptions to deal with and check. - like should it honor directives from just the section mentioned or also from the headers? currently jbangs markdown parsing is quite "dumb".

Maybe a better way would be to use jbang.jar as a dependency and implement this on top of it instead?

[koppor]

I like easy syntax. Therefore jbang tasks.md hello world is nice. (Running task "hello" with parameter "world")

Maybe, there needs to be a magic comment in the first 5 lines?

Maybe as simple as

<!-- jbang tasks -->

?

jbang run-task tasks.md hello world

Would also work -> close to run with expected syntax, but also saying explicitly that it is a task.

[maxandersen]

a whole other way - contribute/fork maid and implement java support that uses jbang: https://github.com/egoist/maid#code-block-languages

[koppor]

That project seems to be unmaintained - and I didn't want to take another project on my list to maintain. 😅