Add API for getting data about using directives' definitions

Author: Gedochao

modules/directives/src/main/scala/scala/build/preprocessing/directives/DirectiveHandler.scala

@@ -46,35 +46,41 @@ trait DirectiveHandler[+T] { self =>
 
   def map[U](f: T => U): DirectiveHandler[U] =
     new DirectiveHandler[U] {
-      def name                   = self.name
-      def usage                  = self.usage
-      override def usageMd       = self.usageMd
-      def description            = self.description
-      override def descriptionMd = self.descriptionMd
-      override def examples      = self.examples
+      def name: String                   = self.name
+      def usage: String                  = self.usage
+      override def usageMd: String       = self.usageMd
+      def description: String            = self.description
+      override def descriptionMd: String = self.descriptionMd
+      override def examples: Seq[String] = self.examples
 
-      def scalaSpecificationLevel = self.scalaSpecificationLevel
+      def scalaSpecificationLevel: SpecificationLevel = self.scalaSpecificationLevel
 
-      def keys = self.keys
+      def keys: Seq[Key] = self.keys
 
-      def handleValues(scopedDirective: ScopedDirective, logger: Logger) =
+      def handleValues(
+        scopedDirective: ScopedDirective,
+        logger: Logger
+      ): Either[BuildException, ProcessedDirective[U]] =
         self.handleValues(scopedDirective, logger)
           .map(_.map(f))
     }
   def mapE[U](f: T => Either[BuildException, U]): DirectiveHandler[U] =
     new DirectiveHandler[U] {
-      def name                   = self.name
-      def usage                  = self.usage
-      override def usageMd       = self.usageMd
-      def description            = self.description
-      override def descriptionMd = self.descriptionMd
-      override def examples      = self.examples
+      def name: String                   = self.name
+      def usage: String                  = self.usage
+      override def usageMd: String       = self.usageMd
+      def description: String            = self.description
+      override def descriptionMd: String = self.descriptionMd
+      override def examples: Seq[String] = self.examples
 
-      def scalaSpecificationLevel = self.scalaSpecificationLevel
+      def scalaSpecificationLevel: SpecificationLevel = self.scalaSpecificationLevel
 
-      def keys = self.keys
+      def keys: Seq[Key] = self.keys
 
-      def handleValues(scopedDirective: ScopedDirective, logger: Logger) =
+      def handleValues(
+        scopedDirective: ScopedDirective,
+        logger: Logger
+      ): Either[BuildException, ProcessedDirective[U]] =
         self.handleValues(scopedDirective, logger).flatMap(_.mapE(f))
     }
 

modules/directives/src/main/scala/scala/build/preprocessing/directives/Directives.scala

@@ -54,4 +54,11 @@ object Directives {
       directives.RequireScalaVersionBounds.handler,
       directives.RequireScope.handler
     ).map(_.mapE(_.buildRequirements))
+
+  def allDirectiveHandlers: Seq[DirectiveHandler[BuildRequirements | BuildOptions]] =
+    usingDirectiveHandlers ++ requireDirectiveHandlers
+
+  def getDirectiveHandler(key: String): Option[DirectiveHandler[BuildRequirements | BuildOptions]] =
+    allDirectiveHandlers.find(_.keys.exists(_.nameAliases.contains(key)))
+
 }

modules/directives/src/test/scala/scala/build/preprocessing/directives/DirectivesTest.scala

@@ -0,0 +1,19 @@
+package scala.build.preprocessing.directives
+
+import com.eed3si9n.expecty.Expecty.expect
+
+class DirectivesTest extends munit.FunSuite {
+  test("get directive handler by key") {
+    val key     = "python"
+    val handler = Directives.getDirectiveHandler(key).get
+    expect(handler.keys.flatMap(_.nameAliases).contains(key))
+    expect(handler.isExperimental)
+    expect(handler.name == "Python")
+    expect(handler.description.nonEmpty)
+    expect(handler.descriptionMd.nonEmpty)
+    expect(handler.usage.nonEmpty)
+    expect(handler.usageMd.nonEmpty)
+    expect(handler.examples.nonEmpty)
+  }
+
+}