More than one sequential undefined in a sequence gets skipped over

Hi,

The test case below fails because more than one consecutive undefined element in a sequence gets skipped over:

const vals =  ["hello", undefined, undefined, undefined, "world"];
expect(asSequence(vals).toArray()).to.deep.equal(vals);

The result with typescript 2.6.2 is

AssertionError: expected [ 'hello', undefined, 'world' ] to deeply equal [ Array(5) ]
      + expected - actual

       [
         "hello"
         [undefined]
      +  [undefined]
      +  [undefined]
         "world"
       ]

Besides this one quirk, this library has been fantastic

[winterbe]

Thanks for explaining your usecase. I will look into this next week so we can properly support undefined values in Sequency.

davemasterdave [e-mail] schrieb am Mi. 3. Jan. 2018 um 02:52:

I am working on a large typescript server application and a lot of the interface definitions have optional parameters. Furthermore, the project has strictNullChecks enabled so all of the optional definitions result in types of T | undefined, resulting in making the null type incompatible.

I ran into this quirk since a lot of the types are possibly also of the type “undefined”. More specifically, I had an iterable fixed length data structure that happened to have several optional types that were not defined in a row. Then, when I was using this library to convert the fixed length object into another iterable object of the same length, I noticed that the output was shorter than what it was supposed to be.

Best Regards

David

— You are receiving this because you commented.

Reply to this email directly, view it on GitHub https://github.com/winterbe/sequency/issues/21#issuecomment-354922245, or mute the thread https://github.com/notifications/unsubscribe-auth/AAdmqd-VR13HoFf9yQ5MMQP3AzBeH6GSks5tGt1mgaJpZM4RQOmK .

[winterbe]

@davemasterdave The issue is fixed with next version 0.19.0 which will be published soon. Sorry for the delay