Illustrates "Bug in specialising config for publishing", https://github.com/isaacs/npm/issues/3121 Creating an npmconf.Conf instance from an existing instance results in the correct lookup chain, but loses named configs.

npm_3121_test.js

// Illustrates "Bug in specialising config for publishing"
// https://github.com/isaacs/npm/issues/3121

var npmconf = require('npmconf');

npmconf.load({ abc: 'my_cli_value'}, function (err, conf) {
    // Print some entries from the initial config
    console.log("Original config:");
    console.log("\tabc: ", conf.get('abc', 'cli'));
    console.log("\ttag: ", conf.get('tag'));

    // Create a publishConfig
    var publishConfig = { tag: 'new_tag' },
        pubConf = new npmconf.Conf(conf);

    // Prepend publishConfig in the same way that npm's 'publish' does
    pubConf.unshift(Object.keys(publishConfig).reduce(function (s, k) {
        s[k] = publishConfig[k];
        return s;
    }, {}));

    // Print the same entries as above, but different tag now
    console.log("Publish config:");
    console.log("\tabc: ", pubConf.get('abc', 'cli')); // undefined; no named configs now
    console.log("\ttag: ", pubConf.get('tag'));

    // Try to set some values in pubConf
    pubConf.set('abc', 'my_internal_value'); // okay; not a named config
    pubConf.set('tag', 'another_new_tag', 'user'); // error; no named configs exist
});