javascript - Strange unnamed property in JSON error object -

i'm using pg-promise in node.js console script.

node version: v0.10.38 pg-promise version: 1.1.4

i got connection error due trivial misconfiguration problem doesn't care. want script alert me rich explanation of problem.

if take error object passed error handler callback , send "as is" console via console.log(), ca see text "no pg_hba.conf entry host "127.0.0.1" in manner can see in labelled "output 1".

but if doesn't seem valid json object , don't know how access property has message.

also, if log result of json.stringifgy() on object, information disappears.

is error of pg-promise implementation? or kind of json hidden attributes , can accessed in way?.

below reproduction of issue:

source code:

var pgplib = require('pg-promise'); var pgp = pgplib({}); var db = pgp({         host: "localhost",         database: "__db_name__",         user: "__db_user__",         password: "__db_password__", });  db.query("select 'foo'").then(         function(){                 console.log ("works!!");         },         function(err){                 console.log("error!!", err); // (output 1)                 // console.log("error!!", json.stringify(err)); // (output 2)         }  ); 

output 1:

error!! { [error: no pg_hba.conf entry host "127.0.0.1", user "reports", database "ruminant", ssl off]   name: 'error',   length: 143,   severity: 'fatal',   code: '28000',   detail: undefined,   hint: undefined,   position: undefined,   internalposition: undefined,   internalquery: undefined,   where: undefined,   schema: undefined,   table: undefined,   column: undefined,   datatype: undefined,   constraint: undefined,   file: 'auth.c',   line: '493',   routine: 'clientauthentication' } 

output 2:

error!! {"name":"error","length":143,"severity":"fatal","code":"28000","file":"auth.c","line":"493","routine":"clientauthentication"} 

edit:

as trott said (thanks), can obtain string using .tostring() method (or forcing string coercion).

but, anyway, below output doesn't seem valid json me.

i figured out achieve same effect overloading .tostring() method in object's prototype, can't:

var foo = function(){};  object.defineproperty(foo.prototype, "tostring", {     enumerable: false,     value: function() {         return "some hidden data";     } });  var bar = new foo(); console.log("1:", bar, bar.tostring()); bar.otherstuff = "foobar"; console.log("2:", bar, bar.tostring()); 

outputs:

1: {} hidden data 2: { otherstuff: 'foobar' } hidden data 

to error message error object without other stuff, use .tostring().

console.log('error! ', err.tostring()); 

if use string concatenation, should have same effect:

console.log('error! ' + err); 

the latter way seems how pg-promise readme example code handles errors.

i've tested both of these pg-promise , work, print "error: " part of message, don't need include 'error! ' did.