CLI commands with object results print js-but-not-json

[sparr]

> storage.db['rooms.objects'].find({room: 'W1N7', type: 'controller'})
[ { room: 'W1N7',
    type: 'controller',
    x: 41,
    y: 31,
    level: 0,
    _id: 'fd2c0774d801520',
    meta: { revision: 0, created: 1477476568448, version: 0 },
    '$loki': 239 } ]

It would be a lot easier to have other programs interact with the CLI if this response was valid JSON instead of just valid JS. I think the only change would be to use double quotes, and to quote the keys.

This could be a problem with lokijs. I wasn't able to follow the behavior of the CLI code far enough to find out.

[RiftLurker]

I think it makes sense to return actual js-objects, as you might want to continue working with them inside the CLI.
If you want a JSON output, you can use JSON.stringify.

[TooAngel]

The point here is, that you get a js object as a string back and need to parse (eval) it somehow to work with the data.
So transferring it over the socket as something parseable (JSON) would help to work with.

[sparr]

@PostCrafter returning actual js-objects would be an improvement. All we're seeing here is the stringification of the object. If it was in JSON, it would still be valid JS, but as things sit now it's valid JS without being valid JSON.

[AlinaNova21]

I agree, the current JS objects are fine, if you need json then append .then(r=>JSON.stringify(r)) to the command. The CLI does not work well with external scripting and tools anyway. If you want that much control, a mod is much better.

[sparr]

@ags131 what does the current output gain us? Why would you want to stringify js objects in a way that isn't json?

[AlinaNova21]

The CLI is not meant for scripting, its meant for human interaction and uses simple, human readable output. theres no need for JSON, rather than wrapping the CLI in tools, its much more effective to write a mod and interface directly with the DB (Or if using screepsmod-mongo, you can just interact with mongo/redis directly)

[sparr]

Would switching to JSON make it less human readable? We're just talking about putting quotes around strings.

[TooAngel]

The advantage of using the CLI interface is having a standard way how to interact with the server independently on the storage backend.
The human readable is a point, but I don't think this should be considered on the network communication level. How to represent the data should be done on the client, the interface should be designed to be used by pieces of software which like parsable data ;-)

[sparr]

For my own edification, and because it might shed light on this dispute, can anyone pinpoint the code where the js object is getting turned into a string? I was unable to find it; the layout of the CLI code stumped me. The contents of that line and/or its location might add some perspective to this matter.

[AlinaNova21]

As a counterpoint, I regularly use the CLI via telnet on machines without screeps installed, requiring a client to get the nicer output would remove that ease of use.

[AlinaNova21]

https://github.com/screeps/backend-local/blob/master/lib/cli/sandbox.js#L40

[sparr]

I am at a loss for figuring out how that code works, where util.inspect comes from, or what callback that function is being called with.

Somewhere there is a block of code that turns a JS object into the string quoted in my original post here. I'd like to find that block.

[TooAngel]

backend-local/lib/cli/server.js

Line 22 in 785013d

socket.write((isResult ? "< " : "") + data + "\r\n", 'utf8');

[sparr]

Oh, I see, util is a node library.

https://nodejs.org/api/util.html#util_util_inspect_object_options

[TooAngel]

The util.inspect() method returns a string representation of object that is primarily useful for debugging. :-)

[sparr]

So, I guess my question here is... Why util.inspect() instead of JSON.stringify(), possibly with util.inspect in the replacer function to handle types that JSON.stringify doesn't handle?

[TheRealMaxion]

JSON.stringify errors on circular references and removes undefined properties

[sparr]

That's a depressingly good answer :(