Moved most of the code into sbtassembly.scalasig package.

Added test for EntryTable

src/main/scala/org/pantsbuild/jarjar/ScalaSigProcessor.scala

@@ -2,6 +2,7 @@ package org.pantsbuild.jarjar
 
 import org.objectweb.asm.{ClassReader, ClassWriter}
 import org.pantsbuild.jarjar.util.{EntryStruct, JarProcessor}
+import sbtassembly.scalasig.ScalaSigClassVisitor
 
 class ScalaSigProcessor(renamer: String => Option[String]) extends JarProcessor {
   override def process(struct: EntryStruct): Boolean = {
@@ -11,7 +12,7 @@ class ScalaSigProcessor(renamer: String => Option[String]) extends JarProcessor
       val classWriter = new ClassWriter(ClassWriter.COMPUTE_MAXS)
       val reader = new ClassReader(struct.data)
 
-      reader.accept(new ScalaSigClassVisitor(struct.name, classWriter, renamer), ClassReader.EXPAND_FRAMES)
+      reader.accept(new ScalaSigClassVisitor(classWriter, renamer), ClassReader.EXPAND_FRAMES)
       struct.data = classWriter.toByteArray
       true
     }

src/main/scala/sbtassembly/Shader.scala

@@ -2,7 +2,7 @@ package sbtassembly
 
 import java.io.File
 
-import org.pantsbuild.jarjar._
+import org.pantsbuild.jarjar.{JJProcessor, _}
 import org.pantsbuild.jarjar.util.EntryStruct
 import sbt._
 

src/main/scala/org/pantsbuild/jarjar/ByteArrayReader.scala → src/main/scala/sbtassembly/scalasig/ByteArrayReader.scala

@@ -1,4 +1,4 @@
-package org.pantsbuild.jarjar
+package sbtassembly.scalasig
 
 // Utility class to read the content of a single table entry
 class ByteArrayReader(bytes: Array[Byte]) extends Nat.Reader {

src/main/scala/org/pantsbuild/jarjar/EntryTable.scala → src/main/scala/sbtassembly/scalasig/EntryTable.scala

@@ -1,4 +1,4 @@
-package org.pantsbuild.jarjar
+package sbtassembly.scalasig
 
 import java.io.ByteArrayOutputStream
 
@@ -19,6 +19,12 @@ class EntryTable(majorVersion: Int, minorVersion: Int, entries: mutable.Buffer[T
     }:_*
   )
 
+  /**
+   * Return the current table entries as an immutable seq.
+   * @return table entries
+   */
+  def toSeq: Seq[TaggedEntry] = entries.toVector
+
   /**
    * Rename term and type entries in this table according to the renamer function.
    * A name or type is referred to by a Ref entry. The existing ref entries are reused to references to them will remain intact.

src/main/scala/org/pantsbuild/jarjar/Nat.scala → src/main/scala/sbtassembly/scalasig/Nat.scala

@@ -1,4 +1,4 @@
-package org.pantsbuild.jarjar
+package sbtassembly.scalasig
 
 /**
  * Utility methods for reading and writing nat encoded numbers.

src/main/scala/org/pantsbuild/jarjar/ScalaSigAnnotationVisitor.scala → src/main/scala/sbtassembly/scalasig/ScalaSigAnnotationVisitor.scala

@@ -1,23 +1,23 @@
-package org.pantsbuild.jarjar
+package sbtassembly.scalasig
 
 import java.io.ByteArrayOutputStream
+
 import org.objectweb.asm.{AnnotationVisitor, ClassVisitor, Opcodes}
+
 import scala.reflect.internal.pickling.ByteCodecs
 
-class ScalaSigClassVisitor(fileName: String, cv: ClassVisitor, renamer: String => Option[String]) extends ClassVisitor(Opcodes.ASM7, cv) {
+class ScalaSigClassVisitor(cv: ClassVisitor, renamer: String => Option[String]) extends ClassVisitor(Opcodes.ASM7, cv) {
 
   override def visitAnnotation(descriptor: String, visible: Boolean): AnnotationVisitor = {
     if (descriptor == "Lscala/reflect/ScalaSignature;" || descriptor == "Lscala/reflect/ScalaLongSignature;") {
-      new ScalaSigAnnotationVisitor(fileName, descriptor, visible, cv, renamer)
+      new ScalaSigAnnotationVisitor(visible, cv, renamer)
     } else {
       super.visitAnnotation(descriptor, visible)
     }
   }
 }
 
 class ScalaSigAnnotationVisitor(
-  fileName: String,
-  descriptor: String,
   visible: Boolean,
   cv: ClassVisitor,
   renamer: String => Option[String]
@@ -44,7 +44,7 @@ class ScalaSigAnnotationVisitor(
     val table = EntryTable.fromBytes(encoded.slice(0, len))
     table.renameEntries(renamer)
 
-    val chars = ubytesToCharArray(mapToNextModSevenBits(scala.reflect.internal.pickling.ByteCodecs.encode8to7(table.toBytes)))
+    val chars = ubytesToCharArray(mapToNextModSevenBits(ByteCodecs.encode8to7(table.toBytes)))
     val utf8EncodedLength = chars.foldLeft(0) { (count, next) => if (next == 0) count + 2 else count + 1}
 
     if (utf8EncodedLength > MaxStringSizeInBytes) {

src/main/scala/org/pantsbuild/jarjar/TaggedEntry.scala → src/main/scala/sbtassembly/scalasig/TaggedEntry.scala

@@ -1,4 +1,4 @@
-package org.pantsbuild.jarjar
+package sbtassembly.scalasig
 
 import java.io.ByteArrayOutputStream
 
@@ -12,8 +12,8 @@ trait TaggedEntry {
 /**
  * Unparsed entry
  */
-case class RawEntry(tag: Int, bytes: Array[Byte]) extends TaggedEntry {
-  override def toBytes: Array[Byte] = bytes
+case class RawEntry(tag: Int, bytes: Seq[Byte]) extends TaggedEntry {
+  override def toBytes: Array[Byte] = bytes.toArray
 }
 
 /**

src/test/scala/sbtassembly/scalasig/EntryTableSpec.scala

@@ -0,0 +1,82 @@
+package sbtassembly.scalasig
+
+import org.scalatest.OptionValues
+import org.scalatest.matchers.should.Matchers
+import org.scalatest.wordspec.AnyWordSpec
+
+import scala.reflect.ScalaSignature
+import scala.reflect.internal.pickling.ByteCodecs
+
+class Test
+
+abstract class Test2 {
+  val test: Test
+}
+
+class EntryTableSpec extends AnyWordSpec with Matchers with OptionValues {
+
+  "entry table" should {
+    "parse annotation bytes" in {
+      val encoded = classOf[Test2].getAnnotation(classOf[ScalaSignature])
+      val bytes = encoded.bytes().getBytes("UTF-8")
+
+      val len = ByteCodecs.decode(bytes)
+      val table = EntryTable.fromBytes(bytes.slice(0, len))
+
+      resolveName(table, "Test") shouldBe Some("sbtassembly.scalasig.Test")
+    }
+
+    "rename package" in {
+      val encoded = classOf[Test2].getAnnotation(classOf[ScalaSignature])
+      val bytes = encoded.bytes().getBytes("UTF-8")
+
+      val len = ByteCodecs.decode(bytes)
+      val table = EntryTable.fromBytes(bytes.slice(0, len))
+
+      table.renameEntries {
+        case pckg if pckg.startsWith("sbtassembly.scalasig") => Some("shaded.sbtassembly.scalasig")
+        case _ => None
+      }
+
+      resolveName(table, "Test") shouldBe Some("shaded.sbtassembly.scalasig.Test")
+
+      table.renameEntries {
+        case pckg if pckg.startsWith("shaded.sbtassembly.scalasig") => Some("sbtassembly.scalasig.shadedtoo")
+        case _ => None
+      }
+
+      resolveName(table, "Test") shouldBe Some("sbtassembly.scalasig.shadedtoo.Test")
+    }
+
+    "return same serialized bytes" in {
+      val encoded = classOf[Test2].getAnnotation(classOf[ScalaSignature])
+      val bytes = encoded.bytes().getBytes("UTF-8")
+
+      val len = ByteCodecs.decode(bytes)
+      val decoded = bytes.slice(0, len)
+      val table = EntryTable.fromBytes(decoded)
+
+      val serialized = table.toBytes
+
+      serialized.length shouldBe decoded.length +- 1  // Scala compiler (sometimes) adds an extra zero. We don't.
+      EntryTable.fromBytes(serialized).toSeq shouldBe table.toSeq
+    }
+  }
+
+  private def resolveName(entryTable: EntryTable, name: String): Option[String] = {
+    val entries = entryTable.toSeq.zipWithIndex
+    def findNameIndex: Option[Int] = entries.collectFirst {
+      case (e: NameEntry, index) if e.name == name => index
+    }
+
+    def findRefEntry(nameIndex: Int): Option[RefEntry] = entries.collectFirst {
+      case (e: RefEntry, _) if e.nameRef == nameIndex => e
+    }
+
+    for {
+      index <- findNameIndex
+      ref <- findRefEntry(index)
+      resolved <- entryTable.resolveRef(ref)
+    } yield resolved
+  }
+}