JarCastingScalafix rules
Deprecated. Please use https://github.com/ohze/scala-rewrites
All rules are migrated to that project!
Old README
This project contains scalafix rules I create when migrating akka to dotty.
ConstructorProcedureSyntax
Remove constructor procedure syntax: def this(..) {..} => def this(..) = {..}
This rule complement to the built-in ProcedureSyntax rule.
Any2StringAdd
Fix https://github.com/scala/scala-rewrites/issues/18(now fixed)- Plus some improvements
ParensAroundLambda
Fix: parentheses are required around the parameter of a lambda
Seq(1).map { i: Int => // rewrite to: Seq(1).map { (i: Int) =>
i + 1
}
Seq(1).map { i => i + 1 } // keep
FinalObject
Remove redundant final modifier for objects:
final object Abc
NullaryOverride
Consistent nullary overriding
trait A {
def i: Int
def u(): Unit
}
trait B {
def i() = 1 // fix by remove `()`: def i = 1
def u = println("hi") // fix by add `()`: def u() = println("hi")
}
ExplicitNonNullaryApply
Compare to fix.scala213.ExplicitNonNullaryApply from scala-rewrites project:
- Pros
-
When I try scala-rewrites' ExplicitNonNullaryApply for akka sources, it crashed!
-
This rule run faster than scala-rewrites' one.
-
Don't need to publishLocal to use. scala/scala-rewrites#32
Just add
"github:ohze/scalafix-rules/ExplicitNonNullaryApply"to.scalafix.conf
-
- Cons
- This rule also add
()to methods that are defined in java and be overridden in scala, eg the calls in ExplicitNonNullaryApplyJavaPending test. Those()s are not required by dotty.
- This rule also add
- Technical note: This rule don't need
scala.meta.internal.pc.ScalafixGlobalto hook into scala-compiler.
ExplicitImplicitTypes
Before scalacenter/scalafix#1180 is fixed, to explicitly add type to implicit def/val/vars (required by dotty) you need:
- Use the built-in ExplicitResultTypes rule with config:
rules = [
ExplicitResultTypes
]
ExplicitResultTypes {
memberVisibility = [] # only rewrite implicit members
}
=> Add type to implicit members of classes, traits
trait T {
// rewrite to `implicit val s: Seq[String] = Nil`
implicit val s = Seq.empty[String]
// rewrite to `implicit def i: Int = 1`
implicit def i = 1
}
- And use this rule
rules = [
"github:ohze/scalafix-rules/ExplicitImplicitTypes"
]
# Optinal
ExplicitImplicitTypes.symbolReplacements {
"scala/concurrent/ExecutionContextExecutor#" = "scala/concurrent/ExecutionContext#"
}
=> Add type to implicit local def/val/vars that its parent is a trait/class
import scala.concurrent.ExecutionContextExecutor
trait T
trait A {
def f() = {
class C {
// rewrite to `implicit val i: Int = 1`
implicit val i = 1
}
???
}
def someEc(): ExecutionContextExecutor
def g() = new T {
// rewrite to `implicit def ec: ExecutionContext = someEc()`
implicit def ec = someEc()
}
}
Usage
- Eg, for ExplicitNonNullaryApply rule:
scalafix --rules=github:ohze/scalafix-rules/ExplicitNonNullaryApply
Dev guide
cd scalafix
sbt ~test
# edit scalafix/rules/src/main/scala/fix/*.scala
Licence
This software is licensed under the Apache 2 license: http://www.apache.org/licenses/LICENSE-2.0
Copyright 2020 Sân Đình (https://sandinh.com)
