Key encoding bad behaviour

The main function of the library, which is exported when you use require('levelup') have different behaviour if you use the option keyEncoding instead of valueEncoding, at least in the Json case.

I have forked the repository to help but I dont know if the problem it’s in the documentation or in the core code, so I just warn.

This is a really simple code to repeat the bug:

var levelup = require('levelup')

var db_a = levelup('./database_a',{ keyEncoding:'json' }),
    db_b = levelup('./database_b',{ valueEncoding:'json' }),
    t    = {'a':1, 'b':{ 'a':'text', 'b':'more_text' }, 'c':3 };

db_a.put('name', t, function (err) {
  if (err) return console.log('Ooops!', err);

  db_a.get('name', function (err, value) {
    if (err) return console.log('Ooops!', err);

    console.log('db_a:');
    console.log('typeof value = ',typeof value);
    console.log(value);
  })
});

db_b.put('name', t, function (err) {
  if (err) return console.log('Ooops!', err);

  db_b.get('name', function (err, value) {
    if (err) return console.log('Ooops!', err);

    console.log('db_b:');
    console.log('typeof value = ',typeof value);    
    console.log(value);
  })
});

And this is the output:

db_b:
typeof value =  object
{ a: 1, b: { a: 'text', b: 'more_text' }, c: 3 }
db_a:
typeof value =  string
[object Object]

Cheers.

[juliangruber]

The reason db_a returns [object Object] instead of your object is that when you don’t specify valueEncoding: 'json' levelUp will convert whatever value you pass to db#put into a leveldb compatible format by calling val.toString() instead of JSON.stringify(val). If you want to use json values, always pass valueEncoding: 'json'.

[duran]

I will try make some minimal changes to README.md and then make a pull requests. If you dont like it, just reject, no hassle. I know it can be a little fussy and the ‘key’, ‘value’ should be clear enought but I think it can help others.

Regards.