Mochaテストで何度もPostgreSQLに接続できません

Question

Expressを使用してNode.jsサーバーを作成しています。サーバはPostgreSQLデータベースに接続します。私はテストのためにMochaを使うことを学んでいますが、テストは "beforeEach"フックでタイムアウトします。 "beforeEach"フックがいくつかのケースでは成功したが、後のケースではタイムアウトに成功したため、これは非常に奇妙です。

私のテストは、test/events.jsとtest/announcements.jsの2つのファイルになりました。タイムアウトエラーは、すべてのテスト（両方のファイル）を実行した場合にのみ発生します。これらを別々に実行すると、すべて正常に動作します。ここで

は、私が個別にテストを実行したときに、私が得るものです：

$ mocha --timeout 30000 "test/announcements.js" 

    Announcements 
GET /api/announcements/list 200 84.757 ms - 175 
    ✓ should GET all the announcements (271ms) 
PUT /api/announcements/create 200 116.172 ms - 16 
GET /api/announcements/list 200 18.715 ms - 238 
    ✓ should PUT a new announcement (211ms) 
GET /api/announcements/list 200 22.114 ms - 175 
POST /api/announcements/edit 200 30.060 ms - 16 
GET /api/announcements/list 200 9.408 ms - 153 
    ✓ should POST an edit to existing announcement (108ms) 
GET /api/announcements/list 200 22.030 ms - 175 
POST /api/announcements/edit 404 13.532 ms - 49 
GET /api/announcements/list 200 18.323 ms - 175 
    ✓ should NOT POST an edit to inexisting announcement (152ms) 
GET /api/announcements/list 200 27.353 ms - 175 
DELETE /api/announcements/delete 200 15.780 ms - 16 
GET /api/announcements/list 200 10.735 ms - 92 
    ✓ should DELETE existing announcement (103ms) 
GET /api/announcements/list 200 20.080 ms - 175 
DELETE /api/announcements/delete 404 7.138 ms - 49 
GET /api/announcements/list 200 5.113 ms - 175 
    ✓ should NOT DELETE inexisting announcement (83ms) 


6 passing (1s) 


$ mocha --timeout 30000 "test/announcements.js" 

    Events 
DEBUG: "beforeEach" hook started 
DEBUG: "beforeEach" hook connected 
DEBUG: "beforeEach" hook queried 1 
DEBUG: "beforeEach" hook queried 2 
GET /api/events/list 200 177.934 ms - 109 
    ✓ should GET all the events (371ms) 
DEBUG: "beforeEach" hook started 
DEBUG: "beforeEach" hook connected 
DEBUG: "beforeEach" hook queried 1 
DEBUG: "beforeEach" hook queried 2 
PUT /api/events/create 200 109.243 ms - 16 
GET /api/events/list 200 10.463 ms - 144 
    ✓ should PUT a new event (201ms) 
DEBUG: "beforeEach" hook started 
DEBUG: "beforeEach" hook connected 
DEBUG: "beforeEach" hook queried 1 
DEBUG: "beforeEach" hook queried 2 
GET /api/events/list 200 7.600 ms - 109 
POST /api/events/edit 200 33.369 ms - 16 
GET /api/events/list 200 5.774 ms - 97 
    ✓ should POST an edit to existing event (89ms) 
DEBUG: "beforeEach" hook started 
DEBUG: "beforeEach" hook connected 
DEBUG: "beforeEach" hook queried 1 
DEBUG: "beforeEach" hook queried 2 
GET /api/events/list 200 10.483 ms - 109 
POST /api/events/edit 404 12.057 ms - 42 
GET /api/events/list 200 10.789 ms - 109 
    ✓ should NOT POST an edit to inexisting event (99ms) 
DEBUG: "beforeEach" hook started 
DEBUG: "beforeEach" hook connected 
DEBUG: "beforeEach" hook queried 1 
DEBUG: "beforeEach" hook queried 2 
GET /api/events/list 200 10.907 ms - 109 
DELETE /api/events/delete 200 16.145 ms - 16 
GET /api/events/list 200 11.006 ms - 63 
    ✓ should DELETE existing event (105ms) 
DEBUG: "beforeEach" hook started 
DEBUG: "beforeEach" hook connected 
DEBUG: "beforeEach" hook queried 1 
DEBUG: "beforeEach" hook queried 2 
GET /api/events/list 200 27.856 ms - 109 
DELETE /api/events/delete 404 17.645 ms - 42 
GET /api/events/list 200 16.777 ms - 109 
    ✓ should NOT DELETE inexisting event (161ms) 


    6 passing (2s) 

をしかし、私はすべてのテストを実行する場合：

DEBUG: "beforeEach" hook ...行は私の test/events.jsコード（下記）から来

$ mocha --timeout 30000 "test/announcements.js" "test/events.js" 

    Announcements 
GET /api/announcements/list 200 84.049 ms - 175 
    ✓ should GET all the announcements (270ms) 
PUT /api/announcements/create 200 132.603 ms - 16 
GET /api/announcements/list 200 15.295 ms - 238 
    ✓ should PUT a new announcement (256ms) 
GET /api/announcements/list 200 32.020 ms - 175 
POST /api/announcements/edit 200 24.557 ms - 16 
GET /api/announcements/list 200 7.385 ms - 153 
    ✓ should POST an edit to existing announcement (142ms) 
GET /api/announcements/list 200 21.938 ms - 175 
POST /api/announcements/edit 404 14.570 ms - 49 
GET /api/announcements/list 200 26.202 ms - 175 
    ✓ should NOT POST an edit to inexisting announcement (110ms) 
GET /api/announcements/list 200 34.236 ms - 175 
DELETE /api/announcements/delete 200 15.140 ms - 16 
GET /api/announcements/list 200 10.347 ms - 92 
    ✓ should DELETE existing announcement (108ms) 
GET /api/announcements/list 200 27.241 ms - 175 
DELETE /api/announcements/delete 404 18.707 ms - 49 
GET /api/announcements/list 200 5.255 ms - 175 
    ✓ should NOT DELETE inexisting announcement (95ms) 

    Events 
DEBUG: "beforeEach" hook started 
DEBUG: "beforeEach" hook connected 
DEBUG: "beforeEach" hook queried 1 
DEBUG: "beforeEach" hook queried 2 
GET /api/events/list 200 122.535 ms - 109 
    ✓ should GET all the events (137ms) 
DEBUG: "beforeEach" hook started 
DEBUG: "beforeEach" hook connected 
DEBUG: "beforeEach" hook queried 1 
DEBUG: "beforeEach" hook queried 2 
PUT /api/events/create 200 11.871 ms - 16 
GET /api/events/list 200 17.677 ms - 144 
    ✓ should PUT a new event (87ms) 
DEBUG: "beforeEach" hook started 
DEBUG: "beforeEach" hook connected 
DEBUG: "beforeEach" hook queried 1 
DEBUG: "beforeEach" hook queried 2 
GET /api/events/list 200 7.059 ms - 109 
POST /api/events/edit 200 9.469 ms - 16 
GET /api/events/list 200 11.117 ms - 97 
    ✓ should POST an edit to existing event (70ms) 
DEBUG: "beforeEach" hook started 
DEBUG: "beforeEach" hook connected 
DEBUG: "beforeEach" hook queried 1 
DEBUG: "beforeEach" hook queried 2 
GET /api/events/list 200 14.007 ms - 109 
POST /api/events/edit 404 10.613 ms - 42 
GET /api/events/list 200 7.941 ms - 109 
    ✓ should NOT POST an edit to inexisting event (82ms) 
DEBUG: "beforeEach" hook started 
    1) "before each" hook for "should DELETE existing event" 


    10 passing (32s) 
    1 failing 

    1) Events "before each" hook for "should DELETE existing event": 
    Error: Timeout of 30000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. 

。失敗した "beforeEach"フックでは、行DEBUG: "beforeEach" hook startedだけを印刷しますが、行... hook connectedは印刷しないことに気付きました。 Postgresデータベースへのこれらの接続に何か問題がありますか？

私はPostgreSQLのログファイルをチェックアウトし、このタイムアウトエラーに気づいたが、ログに次の行を発生しますので、

LOG: could not receive data from client: Connection reset by peer 

、何が起こっています！

let chai = require('chai'); 
let chaiHttp = require('chai-http'); 

var pg = require('pg'); 
let server = require('../app.js'); 
let should = chai.should(); 

chai.use(chaiHttp); 

describe('Events',() => { 

    beforeEach((done) => { // Create some data to the database 

    try { 

     console.log('DEBUG: "beforeEach" hook started'); 

     pg.connect(process.env.DATABASE_URL, function(err, client) { 
     console.log('DEBUG: "beforeEach" hook connected'); 

     if (err) { 
      console.log(err); 
      done(err); 

     } else { 
      client.query('DELETE FROM events', function(err, result) { 

      console.log('DEBUG: "beforeEach" hook queried 1'); 
      if (err) { 
       console.log(err); 
       done(err); 

      } else { 
       client.query(' \ 
       INSERT INTO events (title) VALUES \ 
       (\'Fantastic title!\'), \ 
       (\'Another fantastic title!\')', function(err, result) { 

       console.log('DEBUG: "beforeEach" hook queried 2'); 

       if (err) { 
        console.log(err); 
        done(err); 

       } else { 
        done(); 
       } 
       }); 
      } 
      }); 
     } 
     }); 

    } catch (err) { 
     console.log(err); 
    } 

    }); 

    it('should GET all the events', (done) => { 
    chai.request(server) 
    .get('/api/events/list') 
    .end((err, res) => { 
     res.should.have.status(200); 
     res.body.should.be.an('object'); 
     res.body.success.should.equal(true); 
     res.body.data.should.be.a('array'); 
     res.body.data.length.should.be.eql(2); 

     res.body.data[0].should.be.an('object'); 
     res.body.data[0].title.should.equal('Fantastic title!'); 
     res.body.data[1].should.be.an('object'); 
     res.body.data[1].title.should.equal('Another fantastic title!'); 
     done(); 
    }); 
    }); 

    // There are 5 more very similar it('should ...') cases. 
    // I think they aren't important but tell me if I need to include them too. 
}); 

Answer 1

メリークリスマス

私はそれを得た、タイムアウトエラーを与えるあなたがそう長くテストケースを実行するプロセスのための新しいインスタンスを作成してやっている：

はここにtest/events.jsのための私のコードです。

pg.defaults.poolSize 

ともう一つ、あなたがDBにクエリを実行するたびに接続している - ：何を行うことができ、このようなプロセスの各インスタンスにいくつかのプールサイズを割り当てています。 put done（）; client.query行の後に