documentation for REPL completion is somewhat obscure

[kapouer]

On tab completion - eval will be called with .scope as an input string. It is expected to return an array of scope names to be used for the auto-completion.

that doesn't mean much...

[kapouer]

Of course the obvious interpretation is

repl.start({
    eval: function(cmd, context, filename, cb) {
        if (cmd == ".scope") {
            return cb(null, ["array", "of", "strings"]);
        }
        inst.run(cmd, cb);
    }
});

yet i don't think my eval function is ever called with that cmd argument being equal to ".scope" ?
Anyway i don't get it.

[bnoordhuis]

yet i don't think my eval function is ever called with that cmd argument being equal to ".scope" ?

That's #3544 (comment) - I couldn't make it work either.

[Fishrock123]

I'll keep it on my radar, but I don't think I'll get to looking at it soon.

[udnisap]

Looks like the tab completion is called when it has a object ending with a .

For example try this

var _ = require('lodash');
var repl = require('repl');

var replServer = repl.start({});
replServer.eval = _.wrap(replServer.eval, function(eval, cmd, context, filename, callback) {
    console.warn('eval with:', arguments);
    arguments[4] = _.wrap(callback, function(resultCallback){
        console.warn('result callbackdata:', arguments);
        resultCallback.apply(this, Array.prototype.slice.call(arguments, 1));
    });
    eval.apply(this, Array.prototype.slice.call(arguments, 1));
});

and run on the repl

>Array.<tab>

On tab completion - eval will be called with .scope as an input string. It is expected to return an array of scope names to be used for the auto-completion.

means that if an object in the scope is in the promt with an ending . and user press on tab, eval is called with the object without the .

node implementation is at https://github.com/nodejs/node/blob/v5.x/lib/repl.js

[Trott]

The offending text doesn't appear to be in the REPL docs anymore. I'm going to close this. Please comment or re-open if there's something I'm misunderstanding.