hyphen-case config key support

frohoff · May 6, 2015 · 8f60a99 · 8f60a99
1 parent 5d8456b
commit 8f60a99
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Showing 3 changed files with 50 additions and 12 deletions.
diff --git a/build.sbt b/build.sbt
@@ -55,11 +55,12 @@ javacOptions ++= Seq("-Xlint:unchecked", "-Xlint:deprecation")
 /* dependencies */
 libraryDependencies <++= scalaVersion { sv =>
   Seq(
-    "org.specs2"     %% "specs2"         % "2.3.11"   % "test",
-    "org.scalacheck" %% "scalacheck"     % "1.11.3"   % "test",
-    "com.chuusai"    %% "shapeless"      % "2.0.0"    % "test",
-    "com.typesafe"   %  "config"         % "1.2.1",
-    "org.scala-lang" %  "scala-reflect"  % sv         % "provided")
+    "org.specs2"       %% "specs2"        % "2.3.11"   % "test",
+    "org.scalacheck"   %% "scalacheck"    % "1.11.3"   % "test",
+    "com.chuusai"      %% "shapeless"     % "2.0.0"    % "test",
+    "com.typesafe"     %  "config"        % "1.2.1",
+    "com.google.guava" %  "guava"         % "18.0",
+    "org.scala-lang"   %  "scala-reflect" % sv         % "provided")
 }
 
 /* you may need these repos */

diff --git a/src/main/scala/net/ceedubs/ficus/readers/ArbitraryTypeReader.scala b/src/main/scala/net/ceedubs/ficus/readers/ArbitraryTypeReader.scala
@@ -4,29 +4,56 @@ import net.ceedubs.ficus.util.ReflectionUtils
 import com.typesafe.config.Config
 import scala.language.experimental.macros
 import scala.reflect.internal.{StdNames, SymbolTable, Definitions}
+import com.google.common.base.CaseFormat
 
 trait ArbitraryTypeReader {
   implicit def arbitraryTypeValueReader[T]: ValueReader[T] = macro ArbitraryTypeReaderMacros.arbitraryTypeValueReader[T]
 }
 
 object ArbitraryTypeReader extends ArbitraryTypeReader
 
+trait HyphenCaseArbitraryTypeReader {
+  implicit def arbitraryTypeValueReader[T]: ValueReader[T] = macro ArbitraryTypeReaderMacros.arbitraryTypeValueReaderWithHyphenCase[T]
+}
+
+object HyphenCaseArbitraryTypeReader extends HyphenCaseArbitraryTypeReader
+
 object ArbitraryTypeReaderMacros {
   import scala.reflect.macros.blackbox.Context
 
-  def arbitraryTypeValueReader[T : c.WeakTypeTag](c: Context): c.Expr[ValueReader[T]] = {
+  trait NameMapper {
+    def map(name: String): String
+  }
+
+  object defaultMapper extends NameMapper {
+    def map(name: String) = name
+  }
+
+  object hyphenCaseMapper extends NameMapper {
+    def map(name: String) = CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_HYPHEN, name)
+  }
+
+  def arbitraryTypeValueReaderWithParamMapper[T : c.WeakTypeTag](c: Context, paramMapper: NameMapper): c.Expr[ValueReader[T]] = {
     import c.universe._
 
     reify {
       new ValueReader[T] {
-        def read(config: Config, path: String): T = instantiateFromConfig[T](c)(
+        def read(config: Config, path: String): T = instantiateFromConfig[T](c, paramMapper)(
           config = c.Expr[Config](Ident(TermName("config"))),
           path = c.Expr[String](Ident(TermName("path")))).splice
       }
     }
   }
 
-  def instantiateFromConfig[T : c.WeakTypeTag](c: Context)(config: c.Expr[Config], path: c.Expr[String]): c.Expr[T] = {
+  def arbitraryTypeValueReader[T : c.WeakTypeTag](c: Context): c.Expr[ValueReader[T]] = {
+    arbitraryTypeValueReaderWithParamMapper(c, defaultMapper)
+  }
+
+  def arbitraryTypeValueReaderWithHyphenCase[T : c.WeakTypeTag](c: Context): c.Expr[ValueReader[T]] = {
+    arbitraryTypeValueReaderWithParamMapper(c, hyphenCaseMapper)
+  }
+
+  def instantiateFromConfig[T : c.WeakTypeTag](c: Context, paramMapper: NameMapper)(config: c.Expr[Config], path: c.Expr[String]): c.Expr[T] = {
     import c.universe._
 
     val returnType = c.weakTypeOf[T]
@@ -40,7 +67,7 @@ object ArbitraryTypeReaderMacros {
 
     val instantiationMethod = ReflectionUtils.instantiationMethod[T](c, fail)
 
-    val instantiationArgs = extractMethodArgsFromConfig[T](c)(method = instantiationMethod,
+    val instantiationArgs = extractMethodArgsFromConfig[T](c, paramMapper)(method = instantiationMethod,
       companionObjectMaybe = companionSymbol, config = config, path = path, fail = fail)
     val instantiationObject = companionSymbol.filterNot(_ =>
       instantiationMethod.isConstructor
@@ -49,7 +76,7 @@ object ArbitraryTypeReaderMacros {
     c.Expr[T](Apply(instantiationCall, instantiationArgs))
   }
 
-  def extractMethodArgsFromConfig[T : c.WeakTypeTag](c: Context)(method: c.universe.MethodSymbol, companionObjectMaybe: Option[c.Symbol],
+  def extractMethodArgsFromConfig[T : c.WeakTypeTag](c: Context, paramMapper: NameMapper)(method: c.universe.MethodSymbol, companionObjectMaybe: Option[c.Symbol],
                                               config: c.Expr[Config], path: c.Expr[String], fail: String => Nothing): List[c.Tree] = {
     import c.universe._
 
@@ -58,7 +85,7 @@ object ArbitraryTypeReaderMacros {
     if (!method.isPublic) fail(s"'$decodedMethodName' method is not public")
 
     method.paramLists.head.zipWithIndex map { case (param, index) =>
-      val name = param.name.decodedName.toString
+      val name = paramMapper.map(param.name.decodedName.toString)
       val key = q"""$path + "." + $name"""
       val returnType: Type = param.typeSignatureIn(c.weakTypeOf[T])
 

diff --git a/src/test/scala/net/ceedubs/ficus/readers/ArbitraryTypeReaderSpec.scala b/src/test/scala/net/ceedubs/ficus/readers/ArbitraryTypeReaderSpec.scala
@@ -13,6 +13,7 @@ class ArbitraryTypeReaderSpec extends Spec { def is = s2"""
     instantiate with no apply method but a single constructor with multiple params $instantiateMultiParamConstructor
     instantiate with multiple apply methods if only one returns the correct type $multipleApply
     instantiate with primary constructor when no apply methods and multiple constructors $multipleConstructors
+    instantiate with camel case fields and hyphen case config keys $withCamelCaseFields
     use another implicit value reader for a field $withOptionField
     fall back to a default value on an apply method $fallBackToApplyMethodDefaultValue
     fall back to default values on an apply method if base key isn't in config $fallBackToApplyMethodDefaultValueNoKey
@@ -85,6 +86,14 @@ class ArbitraryTypeReaderSpec extends Spec { def is = s2"""
     instance.foo must_== foo
   }
 
+  def withCamelCaseFields = {
+    import Ficus.{stringValueReader}
+    import HyphenCaseArbitraryTypeReader._
+    val cfg = ConfigFactory.parseString(s"withCamelCaseFields { a-camel-case-field: foo, another-camel-case-field: bar }")
+    val instance = arbitraryTypeValueReader[ClassWithCamelCaseFields].read(cfg, "withCamelCaseFields")
+    (instance.aCamelCaseField must_== "foo") and (instance.anotherCamelCaseField must_== "bar")
+  }
+
   def fallBackToApplyMethodDefaultValue = {
     import Ficus.{optionValueReader, stringValueReader}
     import ArbitraryTypeReader._
@@ -247,8 +256,9 @@ object ArbitraryTypeReaderSpec {
   case class WithReaderInCompanion(foo: String)
 
   object WithReaderInCompanion {
-    implicit val reader: ValueReader[WithReaderInCompanion] = 
+    implicit val reader: ValueReader[WithReaderInCompanion] =
       ValueReader.relative(_ => WithReaderInCompanion("from-companion"))
   }
 
+  class ClassWithCamelCaseFields(val aCamelCaseField: String, val anotherCamelCaseField: String)
 }