index.js

/*
 gulp-imports
 Author: Jim Cowart (http://freshbrewedcode.com/jimcowart)
 License: MIT (http://www.opensource.org/licenses/mit-license)
 Version 0.0.3 (really, it should be 0.0.0.0.0.0.2)
 */

/*global require, module, Buffer */

var fs = require( 'fs' );
var path = require( 'path' );
var evs = require( 'event-stream' );
var g_util = require( 'gulp-util' );

// TODO: adjust these to be more forgiving with whitespace....
var patterns = {
    html: /([<][!][-]{2}).?import[(]?.?["'](.*)["'].?[)]?.?[-]{2}[>]/g,
    js: /([\/]{2}|[\/][*]).?import.?[(]?.?["'](.*)["'].?[)]?[;]?.*?(\n[*][\/])?/g,
    css: /([\/]{2}|[\/][*]).?import[(]?.?["'](.*)["'].?[)]?([*][\/])?/g,
    yaml: /([ \t]*)[-][ ]?import[:][ ]*["'](.*)["']/g,
    yml: /([ \t]*)[-][ ]?import[:][ ]*["'](.*)["']/g,
    json: /([ \t]*)[-][ ]?import[:][ ]*["'](.*)["']/g
};

var getExtension = function( p ) {
    return path.extname( p ).substr( 1 ).toLowerCase();
};

function getImport( ext, contents, dirname ) {
    patterns[ ext ].lastIndex = 0; // OH lastIndex - how I HATE you.
    var match = patterns[ ext ].exec( contents );
    return match ? {
        matchText: match[ 0 ],
        index: match.index,
        path: path.join( dirname, match[ 2 ] )
    } : undefined;
}

function processMatch( _import, contents ) {
    return contents.substring( 0, _import.index ) +
            processFile(
                _import.path,
                String( fs.readFileSync( _import.path ) )
        ) +
            contents.substring( _import.index + _import.matchText.length );
}
function processFile( p, contents ) {
    var ext = getExtension( p );
    var processed = contents,
        _import;
    while (_import = getImport( ext, processed, path.dirname( p ) )) {
        processed = processMatch( _import, processed );
    }
    return processed;
}

module.exports = function() {

    function processImports( file ) {
        var contents = String( file.contents );
        var ext = getExtension( file.path );

        // I'm no stream guru - so I have no idea if this can be done.....yet....
        if ( file.isStream() ) {
            this.emit( 'error', new g_util.PluginError( 'gulp-imports', 'Yikes - sorry about this, but streams are not supported yet.' ) );
        }

        if ( patterns.hasOwnProperty( ext ) ) {
            if ( file.isBuffer() ) {
                contents = processFile( file.path, contents );
                file.contents = new Buffer( contents );
            }
        }

        this.emit( 'data', file );
    }

    return evs.through( processImports );
};