Rename EitherT.liftT to EitherT.liftF (#1947)

* Rename EitherT.liftT to EitherT.liftF To be consistent with OptionT.liftF. * Re-add liftT with a @deprecated notice * Add scalafix rule for renaming EitherT.liftT * Set deprecated since to 1.0.0-RC1 * Update scalafix readme * Update scalafix readme
typelevel · Oct 10, 2017 · 5f19814 · 5f19814
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diff --git a/core/src/main/scala/cats/ApplicativeError.scala b/core/src/main/scala/cats/ApplicativeError.scala
@@ -93,7 +93,7 @@ trait ApplicativeError[F[_], E] extends Applicative[F] {
    * scala> type F[A] = EitherT[State[String, ?], Err, A]
    *
    * scala> val action: PartialFunction[Err, F[Unit]] = {
-   *      |   case Err("one") => EitherT.liftT(State.set("one"))
+   *      |   case Err("one") => EitherT.liftF(State.set("one"))
    *      | }
    *
    * scala> val prog1: F[Int] = (Err("one")).raiseError[F, Int]

diff --git a/core/src/main/scala/cats/data/EitherT.scala b/core/src/main/scala/cats/data/EitherT.scala
@@ -339,12 +339,15 @@ object EitherT extends EitherTInstances {
    * scala> import cats.implicits._
    * scala> val o: Option[Int] = Some(3)
    * scala> val n: Option[Int] = None
-   * scala> EitherT.liftT(o)
+   * scala> EitherT.liftF(o)
    * res0: cats.data.EitherT[Option,Nothing,Int] = EitherT(Some(Right(3)))
-   * scala> EitherT.liftT(n)
+   * scala> EitherT.liftF(n)
    * res1: cats.data.EitherT[Option,Nothing,Int] = EitherT(None)
    * }}}
    */
+  final def liftF[F[_], A, B](fb: F[B])(implicit F: Functor[F]): EitherT[F, A, B] = right(fb)
+
+  @deprecated("Use EitherT.liftF.", "1.0.0-RC1")
   final def liftT[F[_], A, B](fb: F[B])(implicit F: Functor[F]): EitherT[F, A, B] = right(fb)
 
   /** Transforms an `Either` into an `EitherT`, lifted into the specified `Applicative`.

diff --git a/docs/src/main/tut/datatypes/eithert.md b/docs/src/main/tut/datatypes/eithert.md
@@ -105,7 +105,7 @@ val error: EitherT[Option, String, Int] = EitherT.leftT("Not a number")
 ## From `F[A]` or `F[B]` to `EitherT[F, A, B]`
 
 Similary, use `EitherT.left` and `EitherT.right` to convert an `F[A]` or an `F[B]`
-into an `EitherT`. It is also possible to use `EitherT.liftT` as an alias for
+into an `EitherT`. It is also possible to use `EitherT.liftF` as an alias for
 `EitherT.right`.
 
 ```tut:silent

diff --git a/scalafix/README.md b/scalafix/README.md
@@ -8,7 +8,13 @@ Install the scalafix sbt plugin (globally or in a specific project):
 addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.5.0-RC2")
 ```
 
-run
+to run all rules that apply to version `1.0.0-MF` run
+
+```sh
+sbt scalafix github:typelevel/cats/v1.0.0?sha=c131fe4
+```
+
+to run all rules that apply to the current `1.0.0-SNAPSHOT` run
 
 ```sh
 sbt scalafix github:typelevel/cats/v1.0.0
@@ -20,6 +26,8 @@ sbt scalafix github:typelevel/cats/v1.0.0
 
 - [x] The creation methods (left, right, apply, pure, etc.) in EitherT were improved to take less type arguments.
 
+- [x] EitherT.liftT was renamed to EitherT.liftF
+
 - [x] CartesianBuilder (i.e. |@|) syntax is deprecated, use the apply syntax on tuples instead. E.g. (x |@| y |@| z).map(...) should be replaced by (x, y, z).mapN(...)
 
 - [x] Free.suspend is renamed to Free.defer for consistency.

diff --git a/scalafix/input/src/main/scala/fix/v1_0_0/RenameEitherTLiftT.scala b/scalafix/input/src/main/scala/fix/v1_0_0/RenameEitherTLiftT.scala
@@ -0,0 +1,15 @@
+/*
+rule = "scala:fix.v1_0_0.RenameEitherTLiftT"
+ */
+package fix
+package to1_0_0
+
+object RenameEitherTLiftTTests {
+  import cats.instances.option._
+  import cats.data._
+  import cats.data.EitherT._
+
+  val fa: Option[Int] = Some(42)
+  val et1: EitherT[Option, Nothing, Int] = EitherT.liftT(fa)
+  val et2: EitherT[Option, Nothing, Int] = liftT(fa)
+}
diff --git a/scalafix/output/src/main/scala/fix/v1_0_0/RenameEitherTLiftT.scala b/scalafix/output/src/main/scala/fix/v1_0_0/RenameEitherTLiftT.scala
@@ -0,0 +1,12 @@
+package fix
+package to1_0_0
+
+object RenameEitherTLiftTTests {
+  import cats.instances.option._
+  import cats.data._
+  import cats.data.EitherT._
+
+  val fa: Option[Int] = Some(42)
+  val et1: EitherT[Option, Nothing, Int] = EitherT.liftF(fa)
+  val et2: EitherT[Option, Nothing, Int] = liftF(fa)
+}
diff --git a/scalafix/rules/src/main/scala/fix/Cats_v1_0_0.scala b/scalafix/rules/src/main/scala/fix/Cats_v1_0_0.scala
@@ -215,3 +215,14 @@ case class RemoveSplit(index: SemanticdbIndex)
   }
 
 }
+
+// ref: https://github.com/typelevel/cats/pull/1947
+case class RenameEitherTLiftT(index: SemanticdbIndex)
+  extends SemanticRule(index, "RenameEitherTLiftT") {
+
+  override def fix(ctx: RuleCtx): Patch =
+    ctx.replaceSymbols(
+      "_root_.cats.data.EitherTFunctions.liftT." -> "liftF"
+    )
+
+}