Fixes type params for OptionT.getOrElse(F)

[fcanedo]

Adds a type parameter to getOrElse and getOrElseF to conform to
Option.getOrElse, which allows it to be called without needing a type
hint:

OptionT(Future {
  Option(Right(1))
}).getOrElse(Left("error"))

Instead of:

OptionT(Future {
  Option(Right(1): Either[String, Int])
}).getOrElse(Left("error"))

[codecov-io]

Codecov Report

Merging #2119 into master will increase coverage by 0.04%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2119      +/-   ##
==========================================
+ Coverage   94.63%   94.67%   +0.04%     
==========================================
  Files         325      328       +3     
  Lines        5514     5538      +24     
  Branches      221      199      -22     
==========================================
+ Hits         5218     5243      +25     
+ Misses        296      295       -1

Impacted Files	Coverage Δ
core/src/main/scala/cats/data/OptionT.scala	97.46% <ø> (ø)	⬆️
core/src/main/scala/cats/Invariant.scala	90.47% <0%> (-4.77%)	⬇️
core/src/main/scala/cats/data/IndexedStateT.scala	89.24% <0%> (-0.12%)	⬇️
core/src/main/scala/cats/Semigroupal.scala	100% <0%> (ø)	⬆️
...e/src/main/scala/cats/instances/partialOrder.scala	100% <0%> (ø)	⬆️
core/src/main/scala/cats/ApplicativeError.scala	88.23% <0%> (ø)	⬆️
core/src/main/scala/cats/instances/invariant.scala	100% <0%> (ø)	⬆️
core/src/main/scala/cats/data/Const.scala	100% <0%> (ø)	⬆️
core/src/main/scala/cats/instances/ordering.scala	100% <0%> (ø)	⬆️
...ore/src/main/scala/cats/InvariantSemigroupal.scala	80% <0%> (ø)
... and 13 more

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[ceedubs]

Thanks @fcanedo!

There is a downside to this, which is that if you pass in a value of the wrong type you'll get back something not very useful like OptionT[Future, Any] instead of a compile error.

However, this lines up with the getOrElse definitions on Validated, EitherT, and as you mentioned, Option. 👍 for consistency.

[ceedubs]

It might be nice to add a test for this, since it's functionality that we expect to work.

[kailuowang]

Thanks! A doctest would be nice.

[fcanedo]

I added some unit tests, but what’s a “doctest”?

[kailuowang]

Doctest is really cool! You write code and expected result in Scaladoc, and it runs as a test. You can find plenty of examples here
https://github.com/typelevel/cats/blob/master/core/src/main/scala/cats/Apply.scala
To run them, you run sbt coreJVM/test

[fcanedo]

I can’t reproduce the errors that CI finds locally; any tips?

[kailuowang]

It only happens on scala 2.10 and 2.11. In sbt you can type ++2.11.11 to test in scala 2.11. You might need to use "error".asLeft[Int] to help scala compiler prior to 2.12.

[fcanedo]

@kailuowang, your fix seems to solve the problem. Also, I confirmed that the tests fail to compile if I revert the fix. I think this is done.

What needs to happen to get this merged?

[ceedubs]

Thanks @fcanedo!