source: Dev/trunk/grunt-tasks/svn-ignore.js

var _ = require('underscore')
  , path = require('path');

var regexp = "(\n?)### begin grunt-svn-ignore(.|\n)*### end grunt-svn-ignore[^\n]*(\n?)";

module.exports = function(grunt) {

    grunt.registerMultiTask(
        'svn-ignore',
        "Makes sure the specified source files are ignored in Subversion.",
        function(){
            var done = this.async();

            var tasks = _.chain(this.filesSrc)
                         .groupBy(path.dirname)
                         .map(function(files, dir) {
                             return _.partial(updateSvnIgnore,
                                              dir,
                                              _.chain(files)
                                               .map(path.basename)
                                               .sortBy(_.identity)
                                               .value());
                         })
                         .value();

            grunt.util.async.series(tasks,function(error, results){
                done(error);
            });
        });

    grunt.registerMultiTask(
        'svn-ignore-clean',
        "Clean generated ignore sections in Subversion.",
        function(){
            var done = this.async();

            var tasks = _.chain(this.filesSrc)
                         .map(function(file) {
                             return _.partial(clearSvnIgnore, file);
                         })
                         .value();

            grunt.util.async.series(tasks,function(error, results){
                done(error);
            });
        });

    function updateSvnIgnore(dir,files,callback) {
        if ( !grunt.file.exists(dir) || !grunt.file.isDir(dir) ) {
            callback(null);
            return;
        }
        grunt.log.writeln("Updating svn:ignore for '"+dir+"'");

        readSvnIgnore(dir, function(error, ignore) {
            if ( error ) {
                callback(error);
                return;
            }

            ignore = createIgnore(files, ignore);

            writeSvnIgnore(dir, ignore, function(error) {
                callback(error);
            });
            
        });

    }

    function clearSvnIgnore(dir,callback) {
        if ( !grunt.file.exists(dir) || !grunt.file.isDir(dir) ) {
            callback(null);
            return;
        }
        grunt.log.writeln("Cleaning svn:ignore for '"+dir+"'");

        readSvnIgnore(dir, function(error, ignore) {
            if ( error ) {
                callback(error);
                return;
            }

            ignore = clearIgnore(ignore);
            if ( /^\s*$/.test(ignore) ) {
                deleteSvnIgnore(dir, function(error) {
                    callback(error);
                });
            } else {
                writeSvnIgnore(dir, ignore, function(error) {
                    callback(error);
                });
            }
        });

    }

    function createIgnore(files, currentIgnore) {
        // build autoIgnore section
        var autoIgnore = "### begin grunt-svn-ignore managed ignores\n### edits will be overwritten when grunt svn-ignore is run";
        _.each(files, function(file){
            autoIgnore += "\n"+file;
        });
        autoIgnore += "\n### end grunt-svn-ignore managed ignores";

        // replace iff exists or append
        var re = new RegExp(regexp);
        var newIgnore = currentIgnore || "";
        if ( re.test(newIgnore) ) {
            newIgnore = newIgnore.replace(re,"$1"+autoIgnore+"$2");
        } else {
            newIgnore += "\n"+autoIgnore;
        }

        return newIgnore;
    }
    
    function clearIgnore(currentIgnore) {
        // replace iff exists or append
        var re = new RegExp(regexp);
        var newIgnore = currentIgnore || "";
        newIgnore = newIgnore.replace(re,"");
        return newIgnore;
    }
    
    function readSvnIgnore(dir,callback) {
        return svn(['propget', 'svn:ignore', dir],
                   callback);
    }

    function writeSvnIgnore(dir,ignore,callback) {
        return svn(['propset', 'svn:ignore', ignore, dir],
                   callback);
    }
    
    function deleteSvnIgnore(dir,callback) {
        return svn(['propdel', 'svn:ignore', dir],
                   callback);
    }
    
    function svn(args,callback) {
        grunt.util.spawn({
            cmd: 'svn',
            args: (args || [])
        }, function(error, result) {
            if ( error ) {
                callback(error);
            } else {
                callback(null,result.stdout);
            }
        });
    }
    
};