src/plugman/createpackagejson.js
function createPackageJson (plugin_path) {
    var pluginInfo = new PluginInfo(plugin_path);

    var defaults = {
        id: pluginInfo.id,
        version: pluginInfo.version,
        description: pluginInfo.description,
        license: pluginInfo.license,
        keywords: pluginInfo.getKeywordsAndPlatforms(),
        repository: pluginInfo.repo,
        engines: pluginInfo.getEngines(),
        platforms: pluginInfo.getPlatformsArray()
    };

    var initFile = require.resolve('./init-defaults');
    return initPkgJson(plugin_path, initFile, defaults)
        .then(_ => {
            events.emit('verbose', 'Package.json successfully created');
        });
}
function createPackageJson (plugin_path) {
    var pluginInfo = new PluginInfo(plugin_path);

    var defaults = {
        id: pluginInfo.id,
        version: pluginInfo.version,
        description: pluginInfo.description,
        license: pluginInfo.license,
        keywords: pluginInfo.getKeywordsAndPlatforms(),
        repository: pluginInfo.repo,
        engines: pluginInfo.getEngines(),
        platforms: pluginInfo.getPlatformsArray()
    };

    var initFile = require.resolve('./init-defaults');
    return initPkgJson(plugin_path, initFile, defaults)
        .then(_ => {
            events.emit('verbose', 'Package.json successfully created');
        });
}
returns a promise