refactor: export app.HttpClient that can be overwritten (#1234)

lib/core/dnscache_httpclient.js

@@ -3,16 +3,14 @@
 const dns = require('dns');
 const LRU = require('ylru');
 const urlparse = require('url').parse;
-const urllib = require('urllib');
+const HttpClient = require('./httpclient');
 const utility = require('utility');
 
 const IP_REGEX = /^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/;
 
-class DNSCacheHttpClient extends urllib.HttpClient {
-  constructor(options) {
-    super(options);
-
-    this.app = options.app;
+class DNSCacheHttpClient extends HttpClient {
+  constructor(app) {
+    super(app);
     this.dnsCacheLookupInterval = this.app.config.httpclient.dnsCacheLookupInterval;
     this.dnsCache = new LRU(this.app.config.httpclient.dnsCacheMaxLength);
   }

lib/core/httpclient.js

@@ -5,10 +5,22 @@ const HttpsAgent = require('agentkeepalive').HttpsAgent;
 const urllib = require('urllib');
 const ms = require('humanize-ms');
 
-module.exports = app => {
-  const HttpClient = app.config.httpclient.enableDNSCache ?
-    require('./dnscache_httpclient') : urllib.HttpClient;
 
+class HttpClient extends urllib.HttpClient {
+  constructor(app) {
+    const config = app.config.httpclient;
+    normalizeConfig(app);
+    super({
+      app,
+      defaultArgs: config.request,
+      agent: new Agent(config.httpAgent),
+      httpsAgent: new HttpsAgent(config.httpsAgent),
+    });
+    this.app = app;
+  }
+}
+
+function normalizeConfig(app) {
   const config = app.config.httpclient;
 
   // compatibility
@@ -49,11 +61,6 @@ module.exports = app => {
   if (typeof config.request.timeout === 'string') {
     config.request.timeout = ms(config.request.timeout);
   }
+}
 
-  return new HttpClient({
-    app,
-    defaultArgs: config.request,
-    agent: new Agent(config.httpAgent),
-    httpsAgent: new HttpsAgent(config.httpsAgent),
-  });
-};
+module.exports = HttpClient;

lib/egg.js

@@ -9,7 +9,8 @@ const ContextLogger = require('egg-logger').EggContextLogger;
 const ContextCookies = require('egg-cookies');
 const ContextHttpClient = require('./core/context_httpclient');
 const Messenger = require('./core/messenger');
-const createHttpClient = require('./core/httpclient');
+const DNSCacheHttpClient = require('./core/dnscache_httpclient');
+const HttpClient = require('./core/httpclient');
 const createLoggers = require('./core/logger');
 const Singleton = require('./core/singleton');
 const utils = require('./core/utils');
@@ -42,6 +43,7 @@ class EggApplication extends EggCore {
     this.ContextCookies = ContextCookies;
     this.ContextLogger = ContextLogger;
     this.ContextHttpClient = ContextHttpClient;
+    this.HttpClient = HttpClient;
 
     this.loader.loadConfig();
 
@@ -240,7 +242,11 @@ class EggApplication extends EggCore {
    */
   get httpclient() {
     if (!this[HTTPCLIENT]) {
-      this[HTTPCLIENT] = createHttpClient(this);
+      if (this.config.httpclient.enableDNSCache) {
+        this[HTTPCLIENT] = new DNSCacheHttpClient(this);
+      } else {
+        this[HTTPCLIENT] = new this.HttpClient(this);
+      }
     }
     return this[HTTPCLIENT];
   }

test/fixtures/apps/httpclient-overwrite/app.js

@@ -0,0 +1,21 @@
+'use strict';
+
+const assert = require('assert');
+
+module.exports = app => {
+  class CustomHttpClient extends app.HttpClient {
+    request(url, opt) {
+      return new Promise(resolve => {
+        assert(/^http/.test(url), 'url should start with http, but got ' + url);
+        resolve();
+      }).then(() => {
+        return super.request(url, opt);
+      });
+    }
+
+    curl(url, opt) {
+      return this.request(url, opt);
+    }
+  }
+  app.HttpClient = CustomHttpClient;
+};

test/fixtures/apps/httpclient-overwrite/config/config.default.js

@@ -0,0 +1,7 @@
+'use strict';
+
+exports.httpclient = {
+  request: {
+    timeout: 100,
+  },
+};

test/fixtures/apps/httpclient-overwrite/package.json

@@ -0,0 +1,3 @@
+{
+  "name": "httpclient-overwrite"
+}

test/lib/core/httpclient.test.js

@@ -2,15 +2,15 @@
 
 const assert = require('assert');
 const mm = require('egg-mock');
-const createHttpclient = require('../../../lib/core/httpclient');
+const Httpclient = require('../../../lib/core/httpclient');
 const utils = require('../../utils');
 
 describe('test/lib/core/httpclient.test.js', () => {
   let client;
   let url;
 
   before(() => {
-    client = createHttpclient({
+    client = new Httpclient({
       config: {
         httpclient: {
           request: {},
@@ -151,4 +151,30 @@ describe('test/lib/core/httpclient.test.js', () => {
         });
     });
   });
+
+  describe('overwrite httpclient', () => {
+    let app;
+    before(() => {
+      app = utils.app('apps/httpclient-overwrite');
+      return app.ready();
+    });
+    after(() => app.close());
+
+    it('should set request default global timeout to 100ms', () => {
+      return app.httpclient.curl(`${url}/timeout`)
+        .catch(err => {
+          assert(err);
+          assert(err.name === 'ResponseTimeoutError');
+          assert(err.message.includes('Response timeout for 100ms'));
+        });
+    });
+
+    it('should assert url', () => {
+      return app.httpclient.curl('unknown url')
+        .catch(err => {
+          assert(err);
+          assert(err.message.includes('url should start with http, but got unknown url'));
+        });
+    });
+  });
 });