Get Scala 2.13.4 compiling (#2294)

* Get Scala 2.13.4 compiling

* Fix broken test case, in general use if() else() statements for Vectors rather than pattern match as I am unsure of how to correctly pattern match on Vector0,Vector1,...,Vector6()

* Bump CI to 2.13.4

* OVerride CurrencyUnit.equals() so that it works on Scala 2.13.4, not sure why there was a regression here between Scala versions 2.13.4/2.13.3

* Add explicit unit tests making sure bitcoin/satoshi currency units are equivalent

chain/src/main/scala/org/bitcoins/chain/blockchain/BaseBlockChain.scala

@@ -284,17 +284,18 @@ private[blockchain] trait BaseBlockChainCompObject
     val orderedHeaders =
       connectWalkBackwards(current = childHeader, ancestors = ancestors)
 
-    val initBlockchainOpt = orderedHeaders match {
-      case Vector() | _ +: Vector() =>
+    val initBlockchainOpt = {
+      if (orderedHeaders.isEmpty || orderedHeaders.length == 1) {
         //for the case of _ +: Vector() this means only our
         //child header is in the chain, which means we
         //weren't able to form a blockchain
         None
-      case h +: _ =>
+      } else {
         //find our first header as we need it's Db representation
         //rather than just the raw header
-        val dbOpt = ancestors.find(_.hashBE == h.hashBE)
+        val dbOpt = ancestors.find(_.hashBE == orderedHeaders.head.hashBE)
         Some(Blockchain.fromHeaders(Vector(dbOpt.get)))
+      }
     }
 
     //now let's connect headers

chain/src/main/scala/org/bitcoins/chain/blockchain/ChainHandler.scala

@@ -63,23 +63,25 @@ class ChainHandler(
     val maxWork = groupedChains.keys.max
     val chainsByWork = groupedChains(maxWork)
 
-    val bestHeader: BlockHeaderDb = chainsByWork match {
-      case Vector() =>
+    val bestHeader: BlockHeaderDb = {
+      if (chainsByWork.isEmpty) {
         // This should never happen
         val errMsg = s"Did not find blockchain with work $maxWork"
         logger.error(errMsg)
         throw new RuntimeException(errMsg)
-      case chain +: Vector() =>
-        chain.tip
-      case chain +: rest =>
+      } else if (chainsByWork.length == 1) {
+        chainsByWork.head.tip
+      } else {
+        val tips = chainsByWork
+          .map(_.tip.hashBE.hex)
+          .mkString(", ")
         logger.warn(
-          s"We have multiple competing blockchains with same work, selecting by time: ${(chain +: rest)
-            .map(_.tip.hashBE.hex)
-            .mkString(", ")}")
+          s"We have multiple competing blockchains with same work, selecting by time: $tips")
         //since we have same chainwork, just take the oldest tip
         //as that's "more likely" to have been propagated first
         //and had more miners building on top of it
         chainsByWork.sortBy(_.tip.time).head.tip
+      }
     }
     bestHeader
   }

core-test/src/test/scala/org/bitcoins/core/currency/CurrencyUnitTest.scala

@@ -11,6 +11,13 @@ class CurrencyUnitTest extends BitcoinSUnitTest {
 
   behavior of "Satoshis"
 
+  it must "have 1BTC == 100,000,000 satoshis" in {
+    assert(Bitcoins.one == Satoshis(100000000))
+    assert(Satoshis(100000000) == Bitcoins.one)
+    assert(Satoshis.zero == Bitcoins.zero)
+    assert(Bitcoins.zero == Satoshis.zero)
+  }
+
   it must "have symmetry serialization" in {
     forAll(CurrencyUnitGenerator.satoshis) { satoshis =>
       assert(Satoshis(satoshis.hex) == satoshis)

core/src/main/scala/org/bitcoins/core/currency/CurrencyUnits.scala

@@ -74,6 +74,19 @@ sealed abstract class CurrencyUnit
   def toBigDecimal: BigDecimal
 
   protected def underlying: A
+
+  override def equals(obj: Any): Boolean = {
+    //needed for cases like
+    //1BTC == 100,000,000 satoshis should be true
+    //weirdly enough, this worked in scala version < 2.13.4
+    //but seems to be broken in 2.13.4 :/
+    //try removing this and running code, you should see
+    //failures in the 'walletTest' module
+    obj match {
+      case cu: CurrencyUnit => cu.satoshis == satoshis
+      case _                => false
+    }
+  }
 }
 
 sealed abstract class Satoshis extends CurrencyUnit {

core/src/main/scala/org/bitcoins/core/protocol/ln/LnTaggedFields.scala

@@ -157,11 +157,11 @@ object LnTaggedFields {
           val newRemaining = t.slice(payload.size, t.size)
 
           loop(newRemaining, fields :+ tag)
-        case IndexedSeq() =>
-          fields
         case _ +: _ | _ +: _ +: _ =>
           throw new IllegalArgumentException(
             "Failed to parse LnTaggedFields, needs 15bits of meta data to be able to parse")
+        case _: Vector[_] =>
+          fields
       }
     }
 

core/src/main/scala/org/bitcoins/core/serializers/script/ScriptParser.scala

@@ -119,7 +119,8 @@ sealed abstract class ScriptParser
                  .decodeHex(
                    BytesUtil.flipEndianness(
                      h)) ++ bytesToPushOntoStack.bytes ++ accum)
-        case Vector() => accum
+        case _: Vector[_] =>
+          accum
       }
     }
     if (tryParsingLong(str) && str.size > 1 && str.substring(0, 2) != "0x") {

inThisBuild.sbt

@@ -3,7 +3,7 @@ import sbt.Keys.excludeLintKeys
 import scala.util.Properties
 
 val scala2_12 = "2.12.12"
-val scala2_13 = "2.13.3"
+val scala2_13 = "2.13.4"
 
 scalafmtOnCompile in ThisBuild := !Properties.envOrNone("CI").contains("true")
 

project/CommonSettings.scala

@@ -99,7 +99,9 @@ object CommonSettings {
       "-Ywarn-unused",
       "-unchecked",
       "-deprecation",
-      "-feature"
+      "-feature",
+      "-Ypatmat-exhaust-depth",
+      "off"
     ) ++ commonCompilerOpts ++ {
       if (scalaVersion.startsWith("2.13")) scala2_13CompilerOpts
       else nonScala2_13CompilerOpts