Function loadFile

packages/less/lib/less-node/file-manager.js:18–148

(filename, currentDirectory, options, environment, callback)

    },

    loadFile(filename, currentDirectory, options, environment, callback) {
        let fullFilename;
        const isAbsoluteFilename = this.isPathAbsolute(filename);
        const filenamesTried = [];
        const self = this;
        const prefix = filename.slice(0, 1);
        const explicit = prefix === '.' || prefix === '/';
        let result = null;
        let isNodeModule = false;
        const npmPrefix = 'npm://';

        options = options || {};

        const paths = isAbsoluteFilename ? [''] : [currentDirectory];

        if (options.paths) { paths.push.apply(paths, options.paths); }

        if (!isAbsoluteFilename && paths.indexOf('.') === -1) { paths.push('.'); }

        const prefixes = options.prefixes || [''];
        const fileParts = this.extractUrlParts(filename);

        if (options.syncImport) {
            getFileData(returnData, returnData);
            if (callback) {
                callback(result.error, result);
            }
            else {
                return result;
            }
        }
        else {
            // promise is guaranteed to be asyncronous
            // which helps as it allows the file handle
            // to be closed before it continues with the next file
            return new Promise(getFileData);
        }

        function returnData(data) {
            if (!data.filename) {
                result = { error: data };
            }
            else {
                result = data;
            }
        }

        function getFileData(fulfill, reject) {
            (function tryPathIndex(i) {
                function tryWithExtension() {
                    const extFilename = options.ext ? self.tryAppendExtension(fullFilename, options.ext) : fullFilename;

                    if (extFilename !== fullFilename && !explicit && paths[i] === '.') {
                        try {
                            fullFilename = require.resolve(extFilename);
                            isNodeModule = true;
                        }
                        catch (e) {