keyStream, readStream, valueStream disappear on sublevel

[dweinstein]

the prototype keyStream seems to be lost on the sublevel which may cause incompatibilities for code that expects it to be present, for example level-delete-range

[dweinstein]

I found Level/levelup#53 and see that maybe keyStream is just going away. I'll fork level-delete-range maybe and just have it switch over to createReadStream for good.

[dweinstein]

Here's my test case:

var tap = require('tap');
var test = tap.test;

var db = require('level')('foo');
var sub = require('level-sublevel')(db);

test('db and sub db test', function (t) {

  test('test without sublevel', function (t) {
    t.type(db.createReadStream, 'function');
    t.type(db.keyStream, 'function');
    t.end();
  });

  test('test with sublevel', function (t) {
    t.type(sub.createReadStream, 'function');
    t.type(sub.keyStream, 'function');
    t.end();
  });

  t.end();
});

Result

TAP version 13
# db and sub db test
# test without sublevel
ok 1 type is function
ok 2 type is function
# test with sublevel
ok 3 type is function
not ok 4 type is function
  ---
    file:   /Users/user/git/dweinstein/test/test.js
    line:   18
    column: 7
    stack:
      - |
        getCaller (/Users/user/node_modules/tap/lib/tap-assert.js:418:17)
      - |
        assert (/Users/user/node_modules/tap/lib/tap-assert.js:21:16)
      - |
        Function.equal (/Users/user/node_modules/tap/lib/tap-assert.js:162:10)
      - |
        Function.type (/Users/user/node_modules/tap/lib/tap-assert.js:320:17)
      - |
        Test._testAssert [as type] (/Users/user/node_modules/tap/lib/tap-test.js:87:16)
      - |
        Test.<anonymous> (/Users/user/git/dweinstein/test/test.js:18:7)
      - |
        Test.emit (events.js:117:20)
      - |
        Test.emit (/Users/user/node_modules/tap/lib/tap-test.js:104:8)
      - |
        GlobalHarness.Harness.process (/Users/user/node_modules/tap/lib/tap-harness.js:87:13)
      - |
        process._tickCallback (node.js:442:13)
    found:  undefined
    wanted: function
    diff:   |
      FOUND:  undefined
      WANTED: function
              ^ (at position = 0)
  ...

1..4
# tests 4
# pass  3
# fail  1

[dominictarr]

can you make a pull request for this? Testing that a function exists means nearly nothing - check that it's a function that returns a stream that does the same thing as passing in {keys: true}. That, or make a pull request to level-delete-range that just uses createReadStream.

Probably we should consider keyStream a legacy api, but it probably won't be going anywhere... note that issue is from 2013!

[dweinstein]

the size of the test felt a little silly because the methods are just aliases and the fix is so trivial, but hopefully it'll prevent some other strange issue in the future