[CB-10052] Improve superspawn to allow to handle spawned process io streams

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0.0
• Fix Version/s: 1.1.0
• Component/s: cordova-common
• Assignee: Vladimir Kotikov
• Reporter: Vladimir Kotikov
• Created: 20/Nov/15 08:01
• Updated: 23/Aug/18 06:56
• Resolved: 03/Feb/16 08:56

Description

Sometimes it is useful to process spawned process stdout and stderr in some way before out this to console. The current implementation of superspawn doesn't give a way to do this. One of the cases when this could be helpful - CB-9971 (see https://github.com/apache/cordova-android/pull/240 for some discussion).

The proposed approach is:
1. Add ability to accept any valid stdio configuration, just like the original child_process.spawn does (https://nodejs.org/api/child_process.html#child_process_options_stdio)
2. Give a way to caller to listen to stdout and stderr events. This might be implemented as resultant promise progress notification:

spawn('mycommand', [], {stdio: 'pipe'})
.progress(function (stdio){
    if (stdio.stderr) {
        console.error(stdio.stderr);
    }
})
.then(function(result){
    // do other stuff
})

Another option is to return na object that implements both EventEmitter and Promise interfaces, so anybody might subscribe to its events.

Issue Links

• is related to: CB-10768 Use cordova-common.superspawn in GradleBuilder