download-or-build-purescript


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

``javascript
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

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

$3

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.

`javascript
{
id: 'head'
}
`

##### head:fail

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

`javascript
{
id: 'head:fail',
error:
}
`

##### head:complete

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

`javascript
{
id: 'head:complete'
}
`

##### download-binary

Fires many times while downloading and extracting the prebuilt binary.

entry and response properties are derived from dl-tar.

`javascript
{
id: 'download-binary',
entry: ,
response: {
bytes: ,
headers: