lib/nodes/build.js
function() {

        return Q.all(this.tech
            .getPaths(PATH.resolve(this.root, this.output), this.tech.getBuildSuffixes())
            .map(function(path) {

                return QFS.lastModified(path)
                    .fail(function() {
                        return -1;
                    });

            }))
            .spread(Math.min);

    }
function() {

        return Q.all(this.tech
            .getPaths(PATH.resolve(this.root, this.output), this.tech.getBuildSuffixes())
            .map(function(path) {

                return QFS.lastModified(path)
                    .fail(function() {
                        return -1;
                    });

            }))
            .spread(Math.min);

    }
function ( ) { return Q . all ( this . tech . getPaths ( PATH . resolve ( this . root , this . output ) , this . tech . getBuildSuffixes ( ) ) . map ( function ( path ) { return QFS . lastModified ( path ) . fail ( function ( ) { return - 1 ; } ) ; } ) ) . spread ( Math . min ) ; }
Get files minimum mtime in milliseconds or -1 in case of any file doesn't exist.

@return {Promise * Number}
Get files minimum mtime in milliseconds or - 1 in case of any file doesn t exist .