摩卡測試執行回調失敗兩次

Question

我有一個簡單的Mongoose模式，我正在用Mocha測試;當我使用'success'回調運行測試時，它會正常執行，但是當最後一次測試執行失敗並且似乎再次運行測試時（我得到兩個結論，一個填充錯誤對象，另一個填充錯誤對象，而第二個則返回null錯誤對象）運行下面的結果兩種測試在下面的輸出：

Cabinet: 
    â should return all authorized 
    â should return not authorized <-- it succeeds the first time? 
    1) should return not authorized 


2 passing (42ms) 
1 failing   <--- what? there are only two tests 

1) Cabinet: should return not authorized : 
    Uncaught AssertionError: expected null to exist <--- see test 

該試驗重複

it("should return not authorized error ", function(done){ 
    var newCabinet = { 
     name: "A new cabinet", 
     description: "Some remote cabinet", 
     authorizedBorrowers : ["imatest","imanothertest"], 
     cabinetInventory : [] 
    }; 
    Cabinet.newCabinet(newCabinet, function(err, cabinet){ 
     if (err) { 
      console.log("Unable to create cabinet"); 
      done(err); 
     } 
     Cabinet.isAuthorizedBorrower(cabinet._id, "bob", function(cberr, borrower){ 
      should.exist(cberr); <-- 'expected null to exist' points here 
      done(); 
     }); 
    }); 
}); 

該測試成功

it("should not return unauthorized error ", function(done){ 
    var newCabinet = { 
     name: "A new cabinet", 
     description: "Some remote cabinet", 
     authorizedBorrowers : ["imatest","imanothertest"], 
     cabinetInventory : [] 
    }; 
    Cabinet.newCabinet(newCabinet, function(err, cabinet){ 
     if (err) { 
      console.log("Unable to create cabinet"); 
      done(err); 
     } 
     //console.log("ID " + cabinet._id) 
     Cabinet.isAuthorizedBorrower(cabinet._id, "imatest", function(cberr, borrower){ 
      should.not.exist(cberr); 
      done(); 
     }); 
    }); 
}); 

該模式

var cabinetSchema = new Schema({ 
    name: String, 
    description: String, 
    thumbnail : Buffer, 
    authorizedBorrowers : [], 
    defaultCheckout : {type : Number, default: 0} // default checkout mins = no time 

}); 

var hasBorrower = function(cabinet, borrower){ 
    if (cabinet===null) return false; 
    if (cabinet.authorizedBorrowers.length === 0) return false; 
    return (cabinet.authorizedBorrowers.indexOf(borrower) >= 0) 
} 

cabinetSchema.statics.isAuthorizedBorrower = function(cabinet_id, borrowername, cb){ 
    this.findOne({_id: cabinet_id}, function(err, cabinet){ 
    if (err) cb(err,null); 
    if (!hasBorrower(cabinet, borrowername)) cb(new Error(errorMsgs.borrowerNotAuthorized),null); 
    cb(null,borrowername); 
    }); 
}; 

Answer 1

當你做到這一點，添加return;，以避免調用done回調的兩倍。這是爲摩卡，但也爲一般node.js回調處理。

if (err) { 
     console.log("Unable to create cabinet"); 
     done(err); 
     return; 
    } 

在你的櫥櫃模式

同樣的問題：

if (err) cb(err,null); 

需要退貨或將調用回調兩次並造成混亂（也親切地稱爲之間Node.js的博客爲一體的味道「釋放Zalgo「）。