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'use strict'
const path = require('path')
const http = require('http')
const url = require('url')
const arrayify = require('array-back')
const pathToRegexp = require('path-to-regexp')
const debug = require('debug')('local-web-server')
/**
* @module middleware
*/
exports.proxyRequest = proxyRequest
exports.blacklist = blacklist
exports.mockResponses = mockResponses
exports.mime = mime
function proxyRequest (route, app) {
const httpProxy = require('http-proxy')
const proxy = httpProxy.createProxyServer({
changeOrigin: true
})
return function * proxyMiddleware () {
const next = arguments[arguments.length - 1]
const keys = []
route.re = pathToRegexp(route.from, keys)
route.new = this.url.replace(route.re, route.to)
keys.forEach((key, index) => {
const re = RegExp(`:${key.name}`, 'g')
route.new = route.new
.replace(re, arguments[index] || '')
})
/* test no keys remain in the new path */
keys.length = 0
pathToRegexp(url.parse(route.new).path, keys)
if (keys.length) {
this.throw(500, `[PROXY] Invalid target URL: ${route.new}`)
return next()
}
this.response = false
debug('proxy request', `from: ${this.path}, to: ${url.parse(route.new).href}`)
proxy.once('error', err => {
this.throw(500, `[PROXY] ${err.message}: ${route.new}`)
})
proxy.once('proxyReq', function (proxyReq) {
proxyReq.path = url.parse(route.new).path
})
proxy.web(this.req, this.res, { target: route.new })
}
}
function blacklist (forbid) {
return function blacklist (ctx, next) {
if (forbid.some(expression => pathToRegexp(expression).test(ctx.path))) {
ctx.throw(403, http.STATUS_CODES[403])
} else {
return next()
}
}
}
function mockResponses (options) {
options = options || { root: process.cwd() }
return function mockResponses (ctx, next) {
if (/\.mock.js$/.test(ctx.path)) {
const mocks = arrayify(require(path.join(options.root, ctx.path)))
const testValue = require('test-value')
const t = require('typical')
/* find a mock with compatible method and accepts */
let mock = mocks.find(mock => {
return testValue(mock, {
request: {
method: [ ctx.method, undefined ],
accepts: type => ctx.accepts(type)
}
})
})
/* else take the first mock without a request (no request means 'all requests') */
if (!mock) {
mock = mocks.find(mock => !mock.request)
}
if (mock) {
let mockedResponse = mock.response
if (t.isFunction(mock.response)) {
mockedResponse = new mock.response(ctx)
}
Object.assign(ctx.response, mockedResponse)
}
} else {
return next()
}
}
}
function mime (mimeTypes) {
return function mime (ctx, next) {
return next().then(() => {
const reqPathExtension = path.extname(ctx.path).slice(1)
Object.keys(mimeTypes).forEach(mimeType => {
const extsToOverride = mimeTypes[mimeType]
if (extsToOverride.indexOf(reqPathExtension) > -1) ctx.type = mimeType
})
})
}
}