grunt-contrib-less
Version:
Compile LESS files to CSS
226 lines (192 loc) • 7.19 kB
JavaScript
/*
* grunt-contrib-less
* http://gruntjs.com/
*
* Copyright (c) 2016 Tyler Kellen, contributors
* Licensed under the MIT license.
*/
;
var path = require('path');
var _ = require('lodash');
var async = require('async');
var chalk = require('chalk');
var less = require('less');
module.exports = function(grunt) {
grunt.registerMultiTask('less', 'Compile LESS files to CSS', function() {
var done = this.async();
var options = this.options({
banner: ''
});
if (this.files.length < 1) {
grunt.verbose.warn('Destination not written because no source files were provided.');
}
var tally = {
sheets: 0,
maps: 0
};
async.eachSeries(this.files, function(f, nextFileObj) {
var destFile = f.dest;
var files = f.src.filter(function(filepath) {
// Warn on and remove invalid source files (if nonull was set).
if (!grunt.file.exists(filepath)) {
grunt.log.warn('Source file "' + filepath + '" not found.');
return false;
}
return true;
});
if (files.length === 0) {
if (f.src.length < 1) {
grunt.log.warn('Destination ' + chalk.cyan(destFile) + ' not written because no source files were found.');
}
// No src files, goto next target. Warn would have been issued above.
return nextFileObj();
}
var compiled = [];
var i = 0;
async.concatSeries(files, function(file, next) {
if (i++ > 0) {
options.banner = '';
}
compileLess(file, destFile, options)
.then(function(output) {
compiled.push(output.css);
if (options.sourceMap && !options.sourceMapFileInline) {
var sourceMapFilename = options.sourceMapFilename;
if (!sourceMapFilename) {
sourceMapFilename = destFile + '.map';
}
if (typeof sourceMapFilename === 'function') {
try {
sourceMapFilename = sourceMapFilename(destFile);
} catch (e) {
sourceMapFilename = destFile + '.map';
grunt.fail.warn(wrapError(e, 'Generating sourceMapFilename failed.'));
}
}
grunt.file.write(sourceMapFilename, output.map);
grunt.verbose.writeln('File ' + chalk.cyan(sourceMapFilename) + ' created.');
tally.maps++;
}
process.nextTick(next);
},
function(err) {
nextFileObj(err);
});
}, function() {
if (compiled.length < 1) {
grunt.log.warn('Destination ' + chalk.cyan(destFile) + ' not written because compiled files were empty.');
} else {
var allCss = compiled.join(options.compress ? '' : grunt.util.normalizelf(grunt.util.linefeed));
// Add a process step to modify the written CSS
if ( typeof options.process === 'function' ) {
allCss = options.process( allCss, destFile );
}
grunt.file.write(destFile, allCss);
grunt.verbose.writeln('File ' + chalk.cyan(destFile) + ' created');
tally.sheets++;
}
nextFileObj();
});
}, function () {
if (tally.sheets) {
grunt.log.ok(tally.sheets + ' ' + grunt.util.pluralize(tally.sheets, 'stylesheet/stylesheets') + ' created.');
}
if (tally.maps) {
grunt.log.ok(tally.maps + ' ' + grunt.util.pluralize(tally.maps, 'sourcemap/sourcemaps') + ' created.');
}
done();
});
});
var compileLess = function(srcFile, destFile, options) {
options = _.assign({filename: srcFile}, options);
options.paths = options.paths || [path.dirname(srcFile)];
if (typeof options.paths === 'function') {
try {
options.paths = options.paths(srcFile);
} catch (e) {
grunt.fail.warn(wrapError(e, 'Generating @import paths failed.'));
}
}
if (options.sourceMap && !options.sourceMapFileInline && !options.sourceMapFilename) {
options.sourceMapFilename = destFile + '.map';
} else if (options.sourceMap && !options.sourceMapFileInline && typeof options.sourceMapFilename === 'function') {
try {
options.sourceMapFilename = options.sourceMapFilename(destFile);
} catch (e) {
grunt.fail.warn(wrapError(e, 'Generating sourceMapFilename failed.'));
}
}
if (typeof options.sourceMapBasepath === 'function') {
try {
options.sourceMapBasepath = options.sourceMapBasepath(srcFile);
} catch (e) {
grunt.fail.warn(wrapError(e, 'Generating sourceMapBasepath failed.'));
}
}
if (typeof options.sourceMapURL === 'function') {
try {
options.sourceMapURL = options.sourceMapURL(destFile);
} catch (e) {
grunt.fail.warn(wrapError(e, 'Generating sourceMapURL failed.'));
}
}
if (typeof options.sourceMap === 'boolean' && options.sourceMap) {
options.sourceMap = {
sourceMapBasepath: options.sourceMapBasepath,
sourceMapFilename: options.sourceMapFilename,
sourceMapInputFilename: options.sourceMapInputFilename,
sourceMapFullFilename: options.sourceMapFullFilename,
sourceMapURL: options.sourceMapURL,
sourceMapRootpath: options.sourceMapRootpath,
outputSourceFiles: options.outputSourceFiles,
sourceMapFileInline: options.sourceMapFileInline
};
}
var srcCode = grunt.file.read(srcFile);
// Equivalent to --modify-vars option.
// Properties under options.modifyVars are appended as less variables
// to override global variables.
var modifyVarsOutput = parseVariableOptions(options.modifyVars);
if (modifyVarsOutput) {
srcCode += '\n' + modifyVarsOutput;
}
// Load custom functions
if (options.customFunctions) {
Object.keys(options.customFunctions).forEach(function(name) {
less.functions.functionRegistry.add(name.toLowerCase(), function() {
var args = [].slice.call(arguments);
args.unshift(less);
var res = options.customFunctions[name].apply(this, args);
return typeof res === 'object' ? res : new less.tree.Anonymous(res);
});
});
}
return less.render(srcCode, options)
.catch(function(err) {
lessError(err, srcFile);
throw err;
});
};
var parseVariableOptions = function(options) {
var pairs = _.toPairs(options);
var output = '';
pairs.forEach(function(pair) {
output += '@' + pair[0] + ':' + pair[1] + ';';
});
return output;
};
var formatLessError = function(e) {
var pos = '[' + 'L' + e.line + ':' + ('C' + e.column) + ']';
return e.filename + ': ' + pos + ' ' + e.message;
};
var lessError = function(e, file) {
var message = less.formatError ? less.formatError(e) : formatLessError(e);
grunt.log.error(message);
grunt.fail.warn('Error compiling ' + file);
};
var wrapError = function (e, message) {
var err = new Error(message);
err.origError = e;
return err;
};
};