work.suroh.tk/node_modules/browser-sync-client/index.js

124 lines
3.1 KiB
JavaScript

"use strict";
var etag = require("etag");
var fresh = require("fresh");
var fs = require("fs");
var path = require("path");
var zlib = require("zlib");
var minifiedScript = path.join(__dirname, "dist", "index.min.js");
var unminifiedScript = path.join(__dirname, "dist", "index.js");
/**
* Does the current request support compressed encoding?
* @param {Object} req
* @returns {boolean}
*/
function supportsGzip(req) {
var accept = req.headers["accept-encoding"];
return accept && accept.indexOf("gzip") > -1;
}
/**
* Set headers on the response
* @param {Object} res
* @param {String} body
*/
function setHeaders(res, body) {
res.setHeader("Cache-Control", "public, max-age=0");
res.setHeader("Content-Type", "text/javascript");
res.setHeader("ETag", etag(body));
}
/**
* @param {Object} req
* @returns {String}
*/
function isConditionalGet(req) {
return req.headers["if-none-match"] || req.headers["if-modified-since"];
}
/**
* Return a not-modified response
* @param {Object} res
*/
function notModified(res) {
res.removeHeader("Content-Type");
res.statusCode = 304;
res.end();
}
function processItems(items) {
return [].concat(items)
.filter(Boolean)
.reduce((stringOutput, item) => {
if (typeof item === 'string') {
return stringOutput + item;
}
if (typeof item === 'function') {
return stringOutput + item();
}
return stringOutput;
}, "");
}
/**
* Public method for returning either a middleware fn
* or the content as a string
* @param {Object} options
* @param requestBody
* @param {String} type - either `file` or `middleware`
* @returns {*}
*/
function init(options, requestBody, type) {
/**
* If the user asked for a file, simply return the string.
*/
if (type && type === "file") {
return processItems(requestBody);
}
/**
* Otherwise return a function to be used a middleware
*/
return function(req, res) {
/**
* default to using the uncompressed string
* @type {String}
*/
var output = processItems(requestBody);
/**
* Set the appropriate headers for caching
*/
setHeaders(res, output);
var resHeaders = res.getHeaders ? res.getHeaders() : res._headers;
if (isConditionalGet(req) && fresh(req.headers, resHeaders)) {
return notModified(res);
}
/**
* If gzip is supported, compress the string once
* and save for future requests
*/
if (supportsGzip(req)) {
res.setHeader("Content-Encoding", "gzip");
var buf = new Buffer(output, "utf-8");
zlib.gzip(buf, function(_, result) {
res.end(result);
});
} else {
res.end(output);
}
};
}
module.exports.middleware = init;
module.exports.plugin = init;
module.exports.minified = function() {
return fs.readFileSync(minifiedScript, "utf8");
};
module.exports.unminified = function() {
return fs.readFileSync(unminifiedScript, "utf8");
};