download-or-build-purescript

First try to download a prebuilt PureScript binary, then build from a source if the prebuilt one is unavailable

const {readdir} = require('fs').promise;
const {execFile} = require('child_process');
const downloadOrBuildPurescript = require('download-or-build-purescript');

downloadOrBuildPurescript({version: '0.12.3'}).subscribe({
  next(event) {
    if (event.id === 'head:complete') {
      console.log('✓ Prebuilt binary exists.');
      return;
    }

    if (event.id === 'download-binary:complete') {
      console.log('✓ Binary downloaded.');
      return;
    }

    if (event.id === 'check-binary:complete') {
      console.log('✓ Binary works correctly.');
      return;
    }
  }
  async complete() {
    await readdirSync('.').includes('purs'); //=> true
    execFile('./purs', ['--version'], (err, stdout) => {
      stdout.toString(); //=> '0.12.3\n'
    });
  }
});

Installation

Use npm.

npm install download-or-build-purescript

API

const downloadOrBuildPurescript = require('download-or-build-purescript');

downloadOrBuildPurescript([options])

options: Object
Return: Observable (Kevin Smith's implementation)

When the Observable is subscribed,

1. it downloads a prebuilt PureScript binary from the PureScript release page
2. if a prebuilt binary is not available, it downloads the PureScript source code and builds a binary form it
3. it puts the binary at the current working directory

while successively sending events to its Observer.

Events

Each event object has id property with one of these values:

• head
• head:fail
• head:complete
• download-binary
• download-binary:fail
• download-binary:complete
• check-binary
• check-binary:fail
• check-binary:complete
• check-stack
• check-stack:complete
• download-source
• download-source:complete
• setup
• setup:complete
• build
• build:complete

head ------------ x -+- check-stack ----- x -+
 |                   |   |                   |
 o                   |   o                   |
 |                   |   |                   |
download-binary - x -+  download-source - x -+
 |                   |   |                   |
 o                   |   o                   |
 |                   |   |                   |
check-binary ---- x -+  setup ----------- x -+
 |                       |                   |
 |                       o                   |
 |                       |                   |
 |                      build ----------- x -+
 |                       |                   |
 o                       o                   |
 |                       |                   |
*****************       *****************   ^^^^^^^
 Downloaded a            Built a binary      Error
 prebuilt binary         from the source    ^^^^^^^
*****************       *****************

head

Fires when it starts to check if a prebuilt binary is provided for the current platform.

{
  id: 'head'
}

head:fail

Fires when it cannot start downloading the binary, for example no prebuilt ones are provided for the current platform.

{
  id: 'head:fail',
  error: <Error>
}

head:complete

Fires when it confirms that a prebuilt binary is provided for the current platform.

{
  id: 'head:complete'
}

download-binary

Fires many times while downloading and extracting the prebuilt binary.

entry and response properties are derived from dl-tar.

{
  id: 'download-binary',
  entry: <ReadEntry>,
  response: {
    bytes: <number>,
    headers: <Object>,
    url: <string>
  }
}

download-binary:fail

Fires when it fails to download the binary somehow.

{
  id: 'download-binary:fail',
  error: <Error>
}

download-binary:complete

Fires when the prebuilt binary is successfully downloaded.

{
  id: 'download-binary:complete'
}

check-binary

Fires when it starts to verify the downloaded prebuilt binary works correctly, by running purs --version.

{
  id: 'check-binary'
}

check-binary:fail

Fires when the downloaded binary doesn't work correctly.

{
  id: 'check-binary:fail',
  error: <Error>
}

check-binary:complete

Fires when it verifies the downloaded binary works correctly.

{
  id: 'check-binary:complete'
}

check-stack

Fires after one of these events: head:fail download-binary:fail check-binary:fail.

path property is the absolute path of the stack command, and version property is its version.

{
  id: 'check-stack',
  path: <string>,
  version: <string>
}

check-stack:complete

Fires after making sure the stack command is installed in your $PATH.

{
  id: 'check-binary:complete'
}

download-source

Fires many times while downloading and extracting the PureScript source code.

entry and response properties are derived from dl-tar.

{
  id: 'download-source',
  entry: <ReadEntry>,
  response: {
    bytes: <number>,
    headers: <Object>,
    url: <string>
  }
}

download-source:complete

Fires when the source code is successfully downloaded.

{
  id: 'download-source'
}

setup setup:complete build build:complete

Inherited from build-purescript.

Errors

Every error passed to the Observer has id property that indicates which step the error occurred at.

// When the `stack` command is not installed
downloadOrBuildPureScript().subscribe({
  error(err) {
    err.message; //=> '`stack` command is not found in your PATH ...'
    err.id; //=> 'check-stack'
  }
});

// When your machine lose the internet connection while downloading the source
downloadOrBuildPureScript().subscribe({
  error(err) {
    err.message; //=> 'socket hang up'
    err.id; //=> 'download-source'
  }
});

Options

Options are directly passed to download-purescript and build-purescript. Note that,

• filter option is not supported.
• revision option is not supported. Use version option instead.

Additionally, you can use the following:

rename

Type: Function
Default: v => v

Receives the original binary name (purs on POSIX, purs.exe on Windows) and modifies the binary name to its return value.

const {extname} = require('path');

downloadOrBuildPurescript('./dest', {
  rename(originalName) {
    const ext = extname(originalName); //=> '' on POSIX, '.exe' on Windows

    return `foo${ext}`;
  }
}).subscribe({
  complete() {
    // Creates a binary to './dest/foo' on POSIX, './dest/foo.exe' on Windows
  }
});

License

ISC License © 2017 - 2019 Shinnosuke Watanabe