npm-shrinkwrap-compare.js

// nodejs script to compare npm-shrinkwrap files
// TODO check errors with files and report nicely

var fs = require('fs');
var path = require('path');

function usage() {
    console.log("USAGE: %s %s (--needs-delete|--compare)"
                 + " <actual-shrinkwrap-file> <target-shrinkwrap-file>",
                 path.basename(process.argv[0]), path.basename(process.argv[1]) );
    process.exit(1);
}

var mode_needs_delete = false;
var mode_compare = false;
var actual_shrinkwrap_file = null;
var target_shrinkwrap_file = null;

for (var i in process.argv) {
    if (i < 2) {
        // node binary, script file
        continue;
    }
    var arg = process.argv[i];
    if (arg == '--needs-delete') { mode_needs_delete = true; }
    else if (arg == '--compare' ) { mode_compare = true; }
    else if (actual_shrinkwrap_file == null) { actual_shrinkwrap_file = arg; }
    else if (target_shrinkwrap_file == null) { target_shrinkwrap_file = arg; }
    else { usage(); }
}

// exactly one mode should be enabled
if (mode_needs_delete == mode_compare) {
    usage();
}

function read_json_file(filename) {
    var file_string = fs.readFileSync(filename, {'encoding': 'utf8'});
    return JSON.parse(file_string);
}

// compare_nodes returns 0 if matching, 1 if different
function compare_nodes(top_lvl, name, node_actual, node_target) {
    var version_target = node_target['version'];
    var version_actual = node_actual ? node_actual['version'] : 'missing';
    if (version_actual != version_target) {
        if (mode_compare) {
            console.log("%s %s (target %s)", name, version_actual, version_target);
        }
        return 1
    }
    
    var ret = 0;
    var deps_target = node_target['dependencies'] ? node_target['dependencies'] : [];
    var deps_actual = node_actual['dependencies'] ? node_actual['dependencies'] : [];
    for (var dep in deps_target) {
        var dep_path = name + '/' + dep;
        if (compare_nodes(false, dep_path, deps_actual[dep], deps_target[dep]) != 0) {
            ret = 1;
            if (mode_needs_delete && top_lvl) {
                console.log(dep);
            }
        }
    }
    if (top_lvl) {
        for (var dep in deps_actual) {
            if(!deps_target[dep]) {
                ret = 1;
                if (mode_compare) {
                    console.log('%s/%s extraneous', name, dep);
                }
            }
        }
    }
    return ret;
}

var shrinkwrap_actual = read_json_file(actual_shrinkwrap_file);
var shrinkwrap_target = read_json_file(target_shrinkwrap_file);
var top_name = shrinkwrap_target['name'];

var proc_status = compare_nodes(true, top_name, shrinkwrap_actual, shrinkwrap_target);
process.exit(proc_status);

latest version properly supports any name for the top-level module