README.md #1

flagged-respawn

A tool for respawning node binaries when special flags are present.

What is it?

Say you wrote a command line tool that runs arbitrary javascript (e.g. task runner, test framework, etc). For the sake of discussion, let's pretend it's a testing harness you've named testify.

Everything is going splendidly until one day you decide to test some code that relies on a feature behind a v8 flag in node (--harmony, for example). Without much thought, you run testify --harmony spec tests.js.

It doesn't work. After digging around for a bit, you realize this produces a process.argv of:

['node', '/usr/local/bin/test', '--harmony', 'spec', 'tests.js']

Crap. The --harmony flag is in the wrong place! It should be applied to the node command, not our binary. What we actually wanted was this:

['node', '--harmony', '/usr/local/bin/test', 'spec', 'tests.js']

Flagged-respawn fixes this problem and handles all the edge cases respawning creates, such as:

Providing a method to determine if a respawn is needed.
Piping stderr/stdout from the child into the parent.
Making the parent process exit with the same code as the child.
If the child is killed, making the parent exit with the same signal.

To see it in action, clone this repository and run npm install / npm run respawn / npm run nospawn.

Sample Usage

#!/usr/bin/env node

const flaggedRespawn = require('flagged-respawn');

// get a list of all possible v8 flags for the running version of node
const v8flags = require('v8flags').fetch();

flaggedRespawn(v8flags, process.argv, function (ready, child) {
  if (ready) {
    console.log('Running!');
    // your cli code here
  } else {
    console.log('Special flags found, respawning.');
  }
  if (process.pid !== child.pid) {
    console.log('Respawned to PID:', child.pid);
  }
});

Release History

2016-03-22 - v0.3.2 - fix issue with v8 flags values being dropped
2014-09-12 - v0.3.1 - use { stdio: 'inherit' } for spawn to maintain colors
2014-09-11 - v0.3.0 - for real this time
2014-09-11 - v0.2.0 - cleanup
2014-09-04 - v0.1.1 - initial release

# flagged-respawn [![Build Status](https://secure.travis-ci.org/js-cli/js-flagged-respawn.svg)](http://travis-ci.org/js-cli/js-flagged-respawn)
> A tool for respawning node binaries when special flags are present.

[![NPM](https://nodei.co/npm/flagged-respawn.png)](https://nodei.co/npm/flagged-respawn/)

## What is it?

Say you wrote a command line tool that runs arbitrary javascript (e.g. task runner, test framework, etc). For the sake of discussion, let's pretend it's a testing harness you've named `testify`.

Everything is going splendidly until one day you decide to test some code that relies on a feature behind a v8 flag in node (`--harmony`, for example).  Without much thought, you run `testify --harmony spec tests.js`.

It doesn't work. After digging around for a bit, you realize this produces a [`process.argv`](http://nodejs.org/docs/latest/api/process.html#process_process_argv) of:

`['node', '/usr/local/bin/test', '--harmony', 'spec', 'tests.js']`

Crap. The `--harmony` flag is in the wrong place! It should be applied to the **node** command, not our binary. What we actually wanted was this:

`['node', '--harmony', '/usr/local/bin/test', 'spec', 'tests.js']`

Flagged-respawn fixes this problem and handles all the edge cases respawning creates, such as:
- Providing a method to determine if a respawn is needed.
- Piping stderr/stdout from the child into the parent.
- Making the parent process exit with the same code as the child.
- If the child is killed, making the parent exit with the same signal.

To see it in action, clone this repository and run `npm install` / `npm run respawn` / `npm run nospawn`.

## Sample Usage

```js
#!/usr/bin/env node

const flaggedRespawn = require('flagged-respawn');

// get a list of all possible v8 flags for the running version of node
const v8flags = require('v8flags').fetch();

flaggedRespawn(v8flags, process.argv, function (ready, child) {
  if (ready) {
    console.log('Running!');
    // your cli code here
  } else {
    console.log('Special flags found, respawning.');
  }
  if (process.pid !== child.pid) {
    console.log('Respawned to PID:', child.pid);
  }
});

```

## Release History

* 2016-03-22 - v0.3.2 - fix issue with v8 flags values being dropped
* 2014-09-12 - v0.3.1 - use `{ stdio: 'inherit' }` for spawn to maintain colors
* 2014-09-11 - v0.3.0 - for real this time
* 2014-09-11 - v0.2.0 - cleanup
* 2014-09-04 - v0.1.1 - initial release

#	Change	User	Description
#1	19553	swellard	Move and rename clients
//guest/perforce_software/helix-web-services/main/source/clients/2016.1.0/javascript/node_modules/flagged-respawn/README.md
#1	18810	tjuricek	First-pass at JavaScript client SDK. JavaScript requires Node with Gulp to "browserfy" the library. It's the easiest way I found to use the swagger-js project; bundle up a wrapping method. There is no JavaScript reference guide. The swagger-js doesn't really document what they do very well, actually. Overall I'm not particularly impressed by swagger-js, it was hard to even figure out what the right method syntax was. We may want to invest time in doing it better. This required setting CORS response headers, which are currently defaulted to a fairly insecure setting.