Merge pull request #175 from softwaremill/simplified-wireResoure-scala2

Implement wireResource for scala 2
softwaremill · Oct 21, 2021 · 5b0f8fc · 5b0f8fc
2 parents 9f7c15d + 0446fc3
commit 5b0f8fc
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diff --git a/README.md b/README.md
@@ -208,6 +208,53 @@ trait UserModule {
 
 This feature is inspired by @yakivy's work on [jam](https://github.com/yakivy/jam).
 
+## Auto wiring
+
+In case you need to build an instance from some particular instances and factory methods it's recommended to use `autowire`. This feature is intended to interpolate with fp libraries (currently we support `cats`).
+
+`autowire` takes as an argument a list which may contain:
+* values (e.g. `new A()`)
+* factory methods (e.g. `C.create _`)
+* cats.effect.Resource (e.g. `cats.effect.Resource[IO].pure(new A())`)
+* cats.effect.IO (e.g. `cats.effect.IO.pure(new A())`)
+Based on the given list it creates a set of available instances and performs `wireRec` bypassing the instances search phase. The result of the wiring is always wrapped in `cats.effect.Resource`. For example:
+
+```Scala
+import cats.effect._
+
+class DatabaseAccess()
+
+class SecurityFilter private (databaseAccess: DatabaseAccess)
+object SecurityFilter {
+  def apply(databaseAccess: DatabaseAccess): SecurityFilter = new SecurityFilter(databaseAccess)
+}
+
+class UserFinder(databaseAccess: DatabaseAccess, securityFilter: SecurityFilter)
+class UserStatusReader(databaseAccess: DatabaseAccess, userFinder: UserFinder)
+
+object UserModule {
+  import com.softwaremill.macwire._
+
+  val theDatabaseAccess: Resource[IO, DatabaseAccess] = Resource.pure(new DatabaseAccess())
+
+  val theUserStatusReader: Resource[IO, UserStatusReader] = autowire[UserStatusReader](theDatabaseAccess)
+}
+```
+
+will generate
+```Scala
+[...]
+object UserModule {
+  import com.softwaremill.macwire._
+
+  val theDatabaseAccess: Resource[IO, DatabaseAccess] = Resource.pure(new DatabaseAccess())
+
+  val theUserStatusReader: Resource[IO, UserStatusReader] = UserModule.this.theDatabaseAccess.flatMap(
+    da => Resource.pure[IO, UserStatusReader](new UserStatusReader(da, new UserFinder(da, SecurityFilter.apply(da))))
+  )
+}
+```
+
 ## Composing modules
 
 Modules (traits or classes containing parts of the object graph) can be combined using inheritance or composition.

diff --git a/build.sbt b/build.sbt
@@ -64,6 +64,8 @@ val scalatest = "org.scalatest" %% "scalatest" % "3.2.9"
 val javassist = "org.javassist" % "javassist" % "3.28.0-GA"
 val akkaActor = "com.typesafe.akka" %% "akka-actor" % "2.6.15"
 val javaxInject = "javax.inject" % "javax.inject" % "1"
+val cats = "org.typelevel" %% "cats-core" % "2.6.1"
+val catsEffect = "org.typelevel" %% "cats-effect" % "3.2.1"
 
 lazy val root = project
   .in(file("."))
@@ -79,7 +81,9 @@ lazy val root = project
       testUtil,
       utilTests,
       macrosAkka,
-      macrosAkkaTests
+      macrosAkkaTests,
+      macrosAutoCats,
+      macrosAutoCatsTests
     ).flatMap(_.projectRefs): _*
   )
 
@@ -167,6 +171,21 @@ lazy val macrosAkkaTests = projectMatrix
   .dependsOn(macrosAkka, testUtil)
   .jvmPlatform(scalaVersions = scala2)
 
+  lazy val macrosAutoCats = projectMatrix
+  .in(file("macrosAutoCats"))
+  .settings(commonSettings)
+  .settings(libraryDependencies ++= Seq(catsEffect, cats))
+  .dependsOn(macros)
+  .jvmPlatform(scalaVersions = scala2)
+  .jsPlatform(scalaVersions = scala2)
+
+  lazy val macrosAutoCatsTests = projectMatrix
+  .in(file("macrosAutoCatsTests"))
+  .settings(testSettings)
+  .settings(libraryDependencies ++= Seq(scalatest, catsEffect, tagging))
+  .dependsOn(macrosAutoCats, testUtil)
+  .jvmPlatform(scalaVersions = scala2)
+
 Compile / compile := {
   // Enabling debug project-wide. Can't find a better way to pass options to scalac.
   System.setProperty("macwire.debug", "")

diff --git a/macros/src/main/scala-2/com/softwaremill/macwire/internals/CompanionCrimper.scala b/macros/src/main/scala-2/com/softwaremill/macwire/internals/CompanionCrimper.scala
@@ -2,45 +2,62 @@ package com.softwaremill.macwire.internals
 
 import scala.reflect.macros.blackbox
 
-private[macwire] class CompanionCrimper [C <: blackbox.Context, T: C#WeakTypeTag](val c: C, log: Logger) {
+private[macwire] class CompanionCrimper[C <: blackbox.Context, T: C#WeakTypeTag](val c: C, log: Logger) {
   import c.universe._
 
   type DependencyResolverType = DependencyResolver[c.type, Type, Tree]
 
   lazy val targetType: Type = implicitly[c.WeakTypeTag[T]].tpe
 
-  lazy val companionType: Option[Type] = if(targetType.companion == NoType) None else Some(targetType.companion)
+  lazy val companionType: Option[Type] = CompanionCrimper.companionType(c)(targetType)
 
-  def isCompanionApply(method: Symbol): Boolean =
+  lazy val applies: Option[List[Symbol]] = CompanionCrimper.applies(c, log)(targetType)
+
+  def applyTree(dependencyResolver: DependencyResolverType): Option[Tree] = CompanionCrimper.applyTree[C](c, log)(targetType, dependencyResolver.resolve(_, _))
+
+}
+
+object CompanionCrimper {
+  private def showApply[C <: blackbox.Context](c: C)(s: c.Symbol): String = s.asMethod.typeSignature.toString
+
+  private def isCompanionApply[C <: blackbox.Context](c: C)(targetType: c.Type, method: c.Symbol): Boolean =
     method.isMethod &&
     method.isPublic &&
     method.asMethod.returnType <:< targetType &&
     method.asMethod.name.decodedName.toString == "apply"
 
-  lazy val applies: Option[List[Symbol]] = log.withBlock("Looking for apply methods of Companion Object") {
-    val as: Option[List[Symbol]] = companionType.map(_.members.filter(isCompanionApply).toList)
-    as.foreach(x => log.withBlock(s"There are ${x.size} apply methods:" ) { x.foreach(c => log(showApply(c))) })
+  private def companionType[C <: blackbox.Context](c: C)(targetType: c.Type): Option[c.Type] = {
+    import c.universe._
+
+    if(targetType.companion == NoType) None else Some(targetType.companion)
+  }
+
+  private def applies[C <: blackbox.Context](c: C, log: Logger)(targetType: c.Type): Option[List[c.Symbol]] = log.withBlock("Looking for apply methods of Companion Object") {
+    val as: Option[List[c.Symbol]] = companionType(c)(targetType).map(_.members.filter(CompanionCrimper.isCompanionApply(c)(targetType, _)).toList)
+    as.foreach(x => log.withBlock(s"There are ${x.size} apply methods:" ) { x.foreach(s => log(showApply(c)(s))) })
     as
   }
 
-  lazy val apply: Option[Symbol] = applies.flatMap( _ match {
-    case applyMethod :: Nil => Some(applyMethod)
-    case _ => None
-  })
+  def applyTree[C <: blackbox.Context](c: C, log: Logger)(targetType: c.Type, resolver: (c.Symbol, c.Type) => c.Tree): Option[c.Tree] = {
+    import c.universe._
 
-  lazy val applySelect: Option[Select] = apply.map(a => Select(Ident(targetType.typeSymbol.companion), a))
+    lazy val apply: Option[Symbol] = CompanionCrimper.applies(c, log)(targetType).flatMap( _ match {
+      case applyMethod :: Nil => Some(applyMethod)
+      case _ => None
+    })
 
-  lazy val applyParamLists: Option[List[List[Symbol]]] = apply.map(_.asMethod.paramLists)
+    lazy val applySelect: Option[Select] = apply.map(a => Select(Ident(targetType.typeSymbol.companion), a))
 
-  def wireParams(dependencyResolver: DependencyResolverType)(paramLists: List[List[Symbol]]): List[List[Tree]] = paramLists.map(_.map(p => dependencyResolver.resolve(p, p.typeSignature)))
+    lazy val applyParamLists: Option[List[List[Symbol]]] = apply.map(_.asMethod.paramLists)
 
-  def applyArgs(dependencyResolver: DependencyResolverType): Option[List[List[Tree]]] = applyParamLists.map(wireParams(dependencyResolver))
+    def wireParams(paramLists: List[List[Symbol]]): List[List[Tree]] = paramLists.map(_.map(p => resolver(p, p.typeSignature)))
 
-  def applyTree(dependencyResolver: DependencyResolverType): Option[Tree] = for {
-    pl: List[List[Tree]] <- applyArgs(dependencyResolver)
-    applyMethod: Tree <- applySelect
-  } yield pl.foldLeft(applyMethod)((acc: Tree, args: List[Tree]) => Apply(acc, args))
+    def applyArgs: Option[List[List[Tree]]] = applyParamLists.map(x => wireParams(x))
 
-  def showApply(c: Symbol): String = c.asMethod.typeSignature.toString
-}
+    for {
+      pl: List[List[Tree]] <- applyArgs
+      applyMethod: Tree <- applySelect
+    } yield pl.foldLeft(applyMethod)((acc: Tree, args: List[Tree]) => Apply(acc, args))
+  }
 
+}
diff --git a/macros/src/main/scala-2/com/softwaremill/macwire/internals/ConstructorCrimper.scala b/macros/src/main/scala-2/com/softwaremill/macwire/internals/ConstructorCrimper.scala
@@ -2,98 +2,139 @@ package com.softwaremill.macwire.internals
 
 import scala.reflect.macros.blackbox
 
-private[macwire] class ConstructorCrimper[C <: blackbox.Context, T: C#WeakTypeTag] (val c: C, log: Logger) {
+private[macwire] class ConstructorCrimper[C <: blackbox.Context, T: C#WeakTypeTag](val c: C, log: Logger) {
   import c.universe._
 
   type DependencyResolverType = DependencyResolver[c.type, Type, Tree]
 
-  lazy val typeCheckUtil = new TypeCheckUtil[c.type](c, log)
-
   lazy val targetType: Type = implicitly[c.WeakTypeTag[T]].tpe
 
   // We need to get the "real" type in case the type parameter is a type alias - then it cannot
   // be directly instantiated
   lazy val targetTypeD: Type = targetType.dealias
 
-  lazy val classOfT: c.Expr[Class[T]] = c.Expr[Class[T]](q"classOf[$targetType]")
+  lazy val constructor: Option[Symbol] = ConstructorCrimper.constructor(c, log)(targetType)
 
-  lazy val publicConstructors: Iterable[Symbol] = {
-    val ctors = targetType.members
-      .filter(m => m.isMethod && m.asMethod.isConstructor && m.isPublic)
-      .filterNot(isPhantomConstructor)
-    log.withBlock(s"There are ${ctors.size} eligible constructors" ) { ctors.foreach(c => log(showConstructor(c))) }
-    ctors
-  }
+  def constructorArgsWithImplicitLookups(dependencyResolver: DependencyResolverType): Option[List[List[Tree]]] =
+    log.withBlock("Looking for targetConstructor arguments with implicit lookups") {
+      constructor.map(_.asMethod.paramLists).map(wireConstructorParamsWithImplicitLookups(dependencyResolver))
+    }
 
-  lazy val primaryConstructor: Option[Symbol] = publicConstructors.find(_.asMethod.isPrimaryConstructor)
+  def constructorTree(dependencyResolver: DependencyResolverType): Option[Tree] =
+    ConstructorCrimper.constructorTree(c, log)(targetType, dependencyResolver.resolve(_, _))
 
-  lazy val injectConstructors: Iterable[Symbol] = {
-    val isInjectAnnotation = (a: Annotation) => a.toString == "javax.inject.Inject"
-    val ctors = publicConstructors.filter(_.annotations.exists(isInjectAnnotation))
-    log.withBlock(s"There are ${ctors.size} constructors annotated with @javax.inject.Inject" ) { ctors.foreach(c => log(showConstructor(c))) }
-    ctors
-  }
+  def wireConstructorParams(
+      dependencyResolver: DependencyResolverType
+  )(paramLists: List[List[Symbol]]): List[List[Tree]] = paramLists.map(
+    _.map(p => dependencyResolver.resolve(p, /*SI-4751*/ ConstructorCrimper.paramType(c)(targetTypeD, p)))
+  )
 
-  lazy val injectConstructor: Option[Symbol] = if(injectConstructors.size > 1) abort(s"Ambiguous constructors annotated with @javax.inject.Inject for type [$targetType]") else injectConstructors.headOption
+  def wireConstructorParamsWithImplicitLookups(
+      dependencyResolver: DependencyResolverType
+  )(paramLists: List[List[Symbol]]): List[List[Tree]] = paramLists.map(_.map {
+    case i if i.isImplicit => q"implicitly[${ConstructorCrimper.paramType(c)(targetType, i)}]"
+    case p                 => dependencyResolver.resolve(p, /*SI-4751*/ ConstructorCrimper.paramType(c)(targetTypeD, p))
+  })
 
-  lazy val constructor: Option[Symbol] = log.withBlock(s"Looking for constructor for $targetType"){
-    val ctor = injectConstructor orElse primaryConstructor
-    ctor.foreach(ctor => log(s"Found ${showConstructor(ctor)}"))
-    ctor
-  }
+}
 
-  lazy val constructorParamLists: Option[List[List[Symbol]]] = constructor.map(_.asMethod.paramLists.filterNot(_.headOption.exists(_.isImplicit)))
+object ConstructorCrimper {
+  def showConstructor[C <: blackbox.Context](c: C)(s: c.Symbol): String = s.asMethod.typeSignature.toString
+
+  private def constructor[C <: blackbox.Context](c: C, log: Logger)(targetType: c.Type) = {
+    import c.universe._
+
+    /** In some cases there is one extra (phantom) constructor.
+      * This happens when extended trait has implicit param:
+      *
+      * {{{
+      *   trait A { implicit val a = ??? };
+      *   class X extends A
+      *   import scala.reflect.runtime.universe._
+      *   typeOf[X].members.filter(m => m.isMethod && m.asMethod.isConstructor && m.asMethod.isPrimaryConstructor).map(_.asMethod.fullName)
+      *
+      *  //res1: Iterable[String] = List(X.<init>, A.$init$)
+      *  }}}
+      *
+      *  The {{{A.$init$}}} is the phantom constructor and we don't want it.
+      *
+      *  In other words, if we don't filter such constructor using this function
+      *  'wireActor-12-noPublicConstructor.failure' will compile and throw exception during runtime but we want to fail it during compilation time.
+      */
+    def isPhantomConstructor(constructor: Symbol): Boolean = constructor.asMethod.fullName.endsWith("$init$")
+
+    lazy val publicConstructors: Iterable[Symbol] = {
+      val ctors = targetType.members
+        .filter(m => m.isMethod && m.asMethod.isConstructor && m.isPublic)
+        .filterNot(isPhantomConstructor)
+      log.withBlock(s"There are ${ctors.size} eligible constructors") { ctors.foreach(s => log(showConstructor(c)(s))) }
+      ctors
+    }
 
-  def constructorArgs(dependencyResolver: DependencyResolverType): Option[List[List[Tree]]] = log.withBlock("Looking for targetConstructor arguments") {
-    constructorParamLists.map(wireConstructorParams(dependencyResolver))
-  }
+    lazy val primaryConstructor: Option[Symbol] = publicConstructors.find(_.asMethod.isPrimaryConstructor)
 
-  def constructorArgsWithImplicitLookups(dependencyResolver: DependencyResolverType): Option[List[List[Tree]]] = log.withBlock("Looking for targetConstructor arguments with implicit lookups") {
-    constructor.map(_.asMethod.paramLists).map(wireConstructorParamsWithImplicitLookups(dependencyResolver))
-  }
+    lazy val injectConstructors: Iterable[Symbol] = {
+      val isInjectAnnotation = (a: Annotation) => a.toString == "javax.inject.Inject"
+      val ctors = publicConstructors.filter(_.annotations.exists(isInjectAnnotation))
+      log.withBlock(s"There are ${ctors.size} constructors annotated with @javax.inject.Inject") {
+        ctors.foreach(s => log(showConstructor(c)(s)))
+      }
+      ctors
+    }
 
-  def constructorTree(dependencyResolver: DependencyResolverType): Option[Tree] =  log.withBlock(s"Creating Constructor Tree for $targetType"){
-    val constructionMethodTree: Tree = Select(New(Ident(targetTypeD.typeSymbol)), termNames.CONSTRUCTOR)
-    constructorArgs(dependencyResolver).map(_.foldLeft(constructionMethodTree)((acc: Tree, args: List[Tree]) => Apply(acc, args)))
+    lazy val injectConstructor: Option[Symbol] =
+      if (injectConstructors.size > 1)
+        c.abort(
+          c.enclosingPosition,
+          s"Ambiguous constructors annotated with @javax.inject.Inject for type [$targetType]"
+        )
+      else injectConstructors.headOption
+
+    log.withBlock(s"Looking for constructor for $targetType") {
+      val ctor = injectConstructor orElse primaryConstructor
+      ctor.foreach(ctor => log(s"Found ${showConstructor(c)(ctor)}"))
+      ctor
+    }
   }
 
-  def wireConstructorParams(dependencyResolver: DependencyResolverType)(paramLists: List[List[Symbol]]): List[List[Tree]] = paramLists.map(_.map(p => dependencyResolver.resolve(p, /*SI-4751*/paramType(p))))
+  private def paramType[C <: blackbox.Context](c: C)(targetTypeD: c.Type, param: c.Symbol): c.Type = {
+    import c.universe._
 
-  def wireConstructorParamsWithImplicitLookups(dependencyResolver: DependencyResolverType)(paramLists: List[List[Symbol]]): List[List[Tree]] = paramLists.map(_.map {
-    case i if i.isImplicit => q"implicitly[${paramType(i)}]"
-    case p => dependencyResolver.resolve(p, /*SI-4751*/ paramType(p))
-  })
-
-  private def paramType(param: Symbol): Type = {
     val (sym: Symbol, tpeArgs: List[Type]) = targetTypeD match {
       case TypeRef(_, sym, tpeArgs) => (sym, tpeArgs)
-      case t => abort(s"Target type not supported for wiring: $t. Please file a bug report with your use-case.")
+      case t =>
+        c.abort(
+          c.enclosingPosition,
+          s"Target type not supported for wiring: $t. Please file a bug report with your use-case."
+        )
     }
     val pTpe = param.typeSignature.substituteTypes(sym.asClass.typeParams, tpeArgs)
     if (param.asTerm.isByNameParam) pTpe.typeArgs.head else pTpe
   }
 
-  /**
-    * In some cases there is one extra (phantom) constructor.
-    * This happens when extended trait has implicit param:
-    *
-    * {{{
-    *   trait A { implicit val a = ??? };
-    *   class X extends A
-    *   import scala.reflect.runtime.universe._
-    *   typeOf[X].members.filter(m => m.isMethod && m.asMethod.isConstructor && m.asMethod.isPrimaryConstructor).map(_.asMethod.fullName)
-    *
-    *  //res1: Iterable[String] = List(X.<init>, A.$init$)
-    *  }}}
-    *
-    *  The {{{A.$init$}}} is the phantom constructor and we don't want it.
-    *
-    *  In other words, if we don't filter such constructor using this function
-    *  'wireActor-12-noPublicConstructor.failure' will compile and throw exception during runtime but we want to fail it during compilation time.
-    */
-  def isPhantomConstructor(constructor: Symbol): Boolean = constructor.asMethod.fullName.endsWith("$init$")
-
-  def showConstructor(c: Symbol): String = c.asMethod.typeSignature.toString
-
-  def abort(msg: String): Nothing = c.abort(c.enclosingPosition, msg)
+  def constructorTree[C <: blackbox.Context](
+      c: C,
+      log: Logger
+  )(targetType: c.Type, resolver: (c.Symbol, c.Type) => c.Tree): Option[c.Tree] = {
+    import c.universe._
+
+    lazy val targetTypeD: Type = targetType.dealias
+
+    lazy val constructor: Option[Symbol] = ConstructorCrimper.constructor(c, log)(targetType)
+
+    lazy val constructorParamLists: Option[List[List[Symbol]]] =
+      constructor.map(_.asMethod.paramLists.filterNot(_.headOption.exists(_.isImplicit)))
+
+    def constructorArgs: Option[List[List[Tree]]] = log.withBlock("Looking for targetConstructor arguments") {
+      constructorParamLists.map(wireConstructorParams(_))
+    }
+
+    def wireConstructorParams(paramLists: List[List[Symbol]]): List[List[Tree]] =
+      paramLists.map(_.map(p => resolver(p, /*SI-4751*/ paramType(c)(targetTypeD, p))))
+
+    log.withBlock(s"Creating Constructor Tree for $targetType") {
+      val constructionMethodTree: Tree = Select(New(Ident(targetTypeD.typeSymbol)), termNames.CONSTRUCTOR)
+      constructorArgs.map(_.foldLeft(constructionMethodTree)((acc: Tree, args: List[Tree]) => Apply(acc, args)))
+    }
+  }
 }