Revise all error messages adopting usability pattern

build.sbt

@@ -22,7 +22,9 @@ lazy val commonSettings = Seq(
         Seq("-Ywarn-unused:_,imports", "-Ywarn-unused:imports", "-release", "8")
       case Some((2, 11)) =>
         Seq()
-      case _ => sys.error("Unsupported scala version")
+      case _ => sys.error("The Scala version you are using is not supported. " +
+        "Please use one of the supported versions: Scala 2.11, 2.12, or 2.13. " +
+        "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
     }
   },
   javacOptions ++= javacReleaseOption,

core/js/src/main/scala/sigma/crypto/Platform.scala

@@ -246,7 +246,9 @@ object Platform {
     case c: Coll[_] => tpe match {
       case STuple(items) => c.tItem == sigma.AnyType && c.length == items.length
       case tpeColl: SCollection[_] => true
-      case _ => sys.error(s"Collection value $c has unexpected type $tpe")
+      case _ => sys.error(s"The value in the collection $c is not the correct type: $tpe. " +
+        "Please make sure the value is of the correct type. " +
+        "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
     }
     case _: Option[_] => tpe.isOption
     case _: Tuple2[_, _] => tpe.isTuple && tpe.asTuple.items.length == 2

core/js/src/main/scala/sigma/reflection/Platform.scala

@@ -19,7 +19,9 @@ object Platform {
         assert(c.clazz == clazz)
         c
       case _ =>
-        sys.error(s"Cannot find RClass data for $clazz")
+        sys.error(s"We couldn't find the data for class $clazz. " +
+          "Please check that the class name is correct and try again. " +
+          "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
       // Uncomment the following line to collect missing reflection data and generate Scala code for it
       //        memoize(classes)(clazz, new JRClass[T](clazz))
     }

core/jvm/src/main/scala/sigma/crypto/Platform.scala

@@ -175,7 +175,9 @@ object Platform {
     case c: Coll[_] => tpe match {
       case STuple(items) => c.tItem == sigma.AnyType && c.length == items.length
       case _: SCollection[_] => true
-      case _ => sys.error(s"Collection value $c has unexpected type $tpe")
+      case _ => sys.error(s"The value in the collection $c is not the correct type: $tpe. " +
+        "Please make sure the value is of the correct type. " +
+        "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
     }
     case _: Option[_] => tpe.isOption
     case _: Tuple2[_, _] => tpe.isTuple && tpe.asTuple.items.length == 2

core/shared/src/main/scala/sigma/Evaluation.scala

@@ -51,7 +51,9 @@ object Evaluation {
       val tpeArg = args(0)
       funcRType(stypeToRType(tpeArg), stypeToRType(tpeRange))
     case _ =>
-      sys.error(s"Don't know how to convert SType $t to RType")
+      sys.error(s"We couldn't process the type $t. " +
+        "Please ensure that $t is compatible with the expected type. " +
+        "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }).asInstanceOf[RType[T#WrappedType]]
 
   /** Transforms RType descriptor of SigmaDsl, which is used during evaluation,
@@ -82,15 +84,19 @@ object Evaluation {
     case ct: CollType[_] => SCollection(rtypeToSType(ct.tItem))
     case ft: FuncType[_,_] => SFunc(rtypeToSType(ft.tDom), rtypeToSType(ft.tRange))
     case pt: PairType[_,_] => STuple(rtypeToSType(pt.tFst), rtypeToSType(pt.tSnd))
-    case _ => sys.error(s"Don't know how to convert RType $t to SType")
+    case _ => sys.error(s"We couldn't process the type $t. " +
+      "Please ensure that $t is compatible with the expected type. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
 
   /** Convert SigmaDsl representation of tuple to ErgoTree serializable representation. */
   def fromDslTuple(value: Any, tupleTpe: STuple): Coll[Any] = value match {
     case t: Tuple2[_,_] => TupleColl(t._1, t._2)
     case a: Coll[Any]@unchecked if a.tItem == sigma.AnyType => a
     case _ =>
-      sys.error(s"Cannot execute fromDslTuple($value, $tupleTpe)")
+      sys.error(s"Failed to process the value $value with type $tupleTpe. " +
+        "Please make sure the value is the correct type. " +
+        "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
 
   /** Convert ErgoTree serializable representation of tuple to SigmaDsl representation. */

core/shared/src/main/scala/sigma/ast/SType.scala

@@ -163,17 +163,23 @@ object SType {
     case _: SOption[_] => x.isInstanceOf[Option[_]]
     case t: STuple =>
       if (t.items.length == 2) x.isInstanceOf[Tuple2[_,_]]
-      else sys.error(s"Unsupported tuple type $t")
+      else sys.error(s"The type $t is not supported. " +
+        "Please make sure you are using a valid type. " +
+        "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
     case tF: SFunc =>
       if (tF.tDom.length == 1) x.isInstanceOf[Function1[_,_]]
-      else sys.error(s"Unsupported function type $tF")
+      else sys.error(s"The type $tF is not supported. " +
+        "Please make sure you are using a valid type. " +
+        "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
     case SContext => x.isInstanceOf[Context]
     case SAvlTree => x.isInstanceOf[AvlTree]
     case SGlobal => x.isInstanceOf[SigmaDslBuilder]
     case SHeader => x.isInstanceOf[Header]
     case SPreHeader => x.isInstanceOf[PreHeader]
     case SUnit => x.isInstanceOf[Unit]
-    case _ => sys.error(s"Unknown type $tpe")
+    case _ => sys.error(s"We don't recognize the type $tpe. " +
+      "Please check the type and make sure it is correct. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
 
 
@@ -346,7 +352,9 @@ object SNumericType extends STypeCompanion {
   override def typeId: TypeCode = 106: Byte
 
   /** Since this object is not used in SMethod instances. */
-  override def reprClass: RClass[_] = sys.error(s"Shouldn't be called.")
+  override def reprClass: RClass[_] = sys.error("Please avoid using the reprClass method. " +
+    "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
+
 }
 
 /** Descriptor of ErgoTree type `Boolean` holding `true` or `false` values. */
@@ -368,14 +376,19 @@ case object SByte extends SPrimType with SEmbeddable with SNumericType with SMon
   override def numericTypeIndex: Int = 0
   override def upcast(v: AnyVal): Byte = v match {
     case b: Byte => b
-    case _ => sys.error(s"Cannot upcast value $v to the type $this")
+    case _ => sys.error(s"We cannot convert value $v to type $this. " +
+      "Please check compatibility between the value and the expected type. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
+
   }
   override def downcast(v: AnyVal): Byte = v match {
     case b: Byte => b
     case s: Short => s.toByteExact
     case i: Int => i.toByteExact
     case l: Long => l.toByteExact
-    case _ => sys.error(s"Cannot downcast value $v to the type $this")
+    case _ => sys.error(s"We cannot convert value $v to type $this. " +
+      "Please check compatibility between the value and the expected type. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
 }
 
@@ -390,13 +403,17 @@ case object SShort extends SPrimType with SEmbeddable with SNumericType with SMo
   override def upcast(v: AnyVal): Short = v match {
     case x: Byte => x.toShort
     case x: Short => x
-    case _ => sys.error(s"Cannot upcast value $v to the type $this")
+    case _ => sys.error(s"We cannot convert value $v to type $this. " +
+      "Please check compatibility between the value and the expected type. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
   override def downcast(v: AnyVal): Short = v match {
     case s: Short => s
     case i: Int => i.toShortExact
     case l: Long => l.toShortExact
-    case _ => sys.error(s"Cannot downcast value $v to the type $this")
+    case _ => sys.error(s"We cannot convert value $v to type $this. " +
+      "Please check compatibility between the value and the expected type. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
 }
 
@@ -412,14 +429,18 @@ case object SInt extends SPrimType with SEmbeddable with SNumericType with SMono
     case x: Byte => x.toInt
     case x: Short => x.toInt
     case x: Int => x
-    case _ => sys.error(s"Cannot upcast value $v to the type $this")
+    case _ => sys.error(s"We cannot convert value $v to type $this. " +
+      "Please check compatibility between the value and the expected type. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
   override def downcast(v: AnyVal): Int = v match {
     case b: Byte => b.toInt
     case s: Short => s.toInt
     case i: Int => i
     case l: Long => l.toIntExact
-    case _ => sys.error(s"Cannot downcast value $v to the type $this")
+    case _ => sys.error(s"We cannot convert value $v to type $this. " +
+      "Please check compatibility between the value and the expected type. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
 }
 
@@ -437,14 +458,18 @@ case object SLong extends SPrimType with SEmbeddable with SNumericType with SMon
     case x: Short => x.toLong
     case x: Int => x.toLong
     case x: Long => x
-    case _ => sys.error(s"Cannot upcast value $v to the type $this")
+    case _ => sys.error(s"We cannot convert value $v to type $this. " +
+      "Please check compatibility between the value and the expected type. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
   override def downcast(v: AnyVal): Long = v match {
     case b: Byte => b.toLong
     case s: Short => s.toLong
     case i: Int => i.toLong
     case l: Long => l
-    case _ => sys.error(s"Cannot downcast value $v to the type $this")
+    case _ => sys.error(s"We cannot convert value $v to type $this. " +
+      "Please check compatibility between the value and the expected type. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
 }
 
@@ -470,7 +495,9 @@ case object SBigInt extends SPrimType with SEmbeddable with SNumericType with SM
       case x: Short => BigInteger.valueOf(x.toLong)
       case x: Int => BigInteger.valueOf(x.toLong)
       case x: Long => BigInteger.valueOf(x)
-      case _ => sys.error(s"Cannot upcast value $v to the type $this")
+      case _ => sys.error(s"We cannot convert value $v to type $this. " +
+        "Please check compatibility between the value and the expected type. " +
+        "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
     }
     CBigInt(bi)
   }
@@ -480,7 +507,9 @@ case object SBigInt extends SPrimType with SEmbeddable with SNumericType with SM
       case x: Short => BigInteger.valueOf(x.toLong)
       case x: Int => BigInteger.valueOf(x.toLong)
       case x: Long => BigInteger.valueOf(x)
-      case _ => sys.error(s"Cannot downcast value $v to the type $this")
+      case _ => sys.error(s"We cannot convert value $v to type $this. " +
+        "Please check compatibility between the value and the expected type. " +
+        "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
     }
     CBigInt(bi)
   }

core/shared/src/main/scala/sigma/data/CSigmaProp.scala

@@ -15,7 +15,9 @@ case class CSigmaProp(sigmaTree: SigmaBoolean) extends SigmaProp with WrapperOf[
   // TODO refactor: remove this (it shouldn't be used in interpreter)
   override def isValid: Boolean = sigmaTree match {
     case p: TrivialProp => p.condition
-    case _ => sys.error(s"Method CostingSigmaProp.isValid is not defined for $sigmaTree")
+    case _ => sys.error(s"The method CostingSigmaProp.isValid does not apply to $sigmaTree. " +
+      "Please make sure to use the correct method for $sigmaTree. " +
+      "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
   }
 
   override def propBytes: Coll[Byte] = {

core/shared/src/main/scala/sigma/kiama/rewriting/Rewriter.scala

@@ -248,7 +248,9 @@ trait Rewriter {
           case _ : NoSuchFieldException =>
             val ctors = clazz.getConstructors
             if (ctors.length == 0)
-              sys.error(s"dup no constructors for ${clazz.getName}")
+              sys.error(s"No constructors found for ${clazz.getName}. " +
+                "Please ensure the class has accessible constructors. " +
+                "If the problem persists, reach out to <a href=\"#\">Customer Care</a> for assistance.")
             else
               (_ : Any, children : Array[AnyRef]) =>
                 makeInstance(ctors(0), children)
@@ -260,8 +262,10 @@ trait Rewriter {
           ctor.newInstance(unboxPrimitives(ctor, children) : _*)
         } catch {
           case _ : IllegalArgumentException =>
-            sys.error(s"""dup illegal arguments: $ctor got (${children.mkString(",")})
-                        |Common cause: term classes are nested in another class, move them to the top level""".stripMargin)
+            sys.error(s"The function $ctor received the same arguments more than once: ${children.mkString(", ")}. " +
+              "This usually happens when functions or methods are inside another class. " +
+              "Try moving them outside the class to fix the problem. " +
+              "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
         }
 
       /** Unbox primitive values in the given array of children using type information of
@@ -620,7 +624,9 @@ trait Rewriter {
                 b += ti
                 false
               case Some(ti) =>
-                sys.error(s"oneMap: got non-pair $ti")
+                sys.error(s"We received a non-key-value pair ($ti) in the oneMap function. " +
+                  "Please ensure all inputs to oneMap are in key-value pair format. " +
+                  "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
               case None =>
                 b += ct
                 true

core/shared/src/main/scala/sigma/kiama/util/Comparison.scala

@@ -42,7 +42,9 @@ object Comparison {
         case (r1 : AnyRef, r2 : AnyRef) =>
           r1 eq r2
         case _ =>
-          sys.error(s"same: comparison of $v1 and $v2, should not be reached")
+          sys.error(s"An unexpected issue occurred with the values $v1 and $v2. " +
+            "This should not happen during regular use. " +
+            "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
       }
 
   /**

core/shared/src/main/scala/sigma/serialization/CoreDataSerializer.scala

@@ -63,7 +63,9 @@ class CoreDataSerializer {
       val len = arr.length
       assert(arr.length == t.items.length, s"Type $t doesn't correspond to value $arr")
       if (len > 0xFFFF)
-        sys.error(s"Length of tuple ${arr.length} exceeds ${0xFFFF} limit.")
+        sys.error(s"The tuple length (${arr.length}) is too long (maximum limit is ${0xFFFF}). " +
+          "Please shorten the tuple to meet the limit. " +
+          "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
       var i = 0
       while (i < arr.length) {
         serialize[SType](arr(i), t.items(i), w)

core/shared/src/main/scala/sigma/serialization/TypeSerializer.scala

@@ -85,7 +85,9 @@ class TypeSerializer {
         serialize(t2, w)
     }
     case STuple(items) if items.length < 2 =>
-      sys.error(s"Invalid Tuple type with less than 2 items $items")
+      sys.error(s"The Tuple with fewer than 2 items ($items) is invalid. " +
+        "Please ensure tuples contain at least 2 items for proper functionality. " +
+        "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
     case tup: STuple => tup.items.length match {
       case 3 =>
         // Triple of types

data/shared/src/main/scala/org/ergoplatform/ErgoBoxCandidate.scala

@@ -151,7 +151,9 @@ object ErgoBoxCandidate {
         val amount = amounts(i)
         if (tokensInTx.isDefined) {
           val tokenIndex = tokensInTx.get.indexWhere(_ == id, 0) // using equality on Coll
-          if (tokenIndex == -1) sys.error(s"failed to find token id ($id) in tx's digest index")
+          if (tokenIndex == -1) sys.error(s"Token ID ($id) not found in the transaction's digest index. " +
+            "Please check the token ID and try again. " +
+            "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
           w.putUInt(tokenIndex)
         } else {
           w.putBytes(id.toArray)
@@ -161,7 +163,9 @@ object ErgoBoxCandidate {
 
       val nRegs = box.additionalRegisters.keys.size
       if (nRegs + ErgoBox.startingNonMandatoryIndex > 255)
-        sys.error(s"The number of non-mandatory indexes $nRegs exceeds ${255 - ErgoBox.startingNonMandatoryIndex} limit.")
+        sys.error(s"The number of non-mandatory indexes ($nRegs) exceeds the maximum limit (${255 - ErgoBox.startingNonMandatoryIndex}). " +
+          "Please decrease the number of non-mandatory indexes to stay within the limit. " +
+          "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
       w.putUByte(nRegs)
       // we assume non-mandatory indexes are densely packed from startingNonMandatoryIndex
       // this convention allows to save 1 bite for each register
@@ -173,8 +177,9 @@ object ErgoBoxCandidate {
           case Some(v) =>
             w.putValue(v)
           case None =>
-            sys.error(s"Set of non-mandatory indexes is not densely packed: " +
-              s"register R$regId is missing in the range [$startReg .. $endReg]")
+            sys.error(s"The non-mandatory indexes are not densely packed: register R$regId is missing in the range [$startReg .. $endReg]. " +
+              "Please fill all registers in this range sequentially. " +
+              "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
         }
       }
     }
@@ -207,7 +212,9 @@ object ErgoBoxCandidate {
           // in v4.x r.getUInt().toInt is used and may return negative Int in which case
           // the error below is thrown
           if (digestIndex < 0 || digestIndex >= nDigests)
-            sys.error(s"failed to find token id with index $digestIndex")
+            sys.error(s"We couldn't find the token ID linked to the index $digestIndex. " +
+              "Please make sure the index value is correct. " +
+              "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
           val amount = r.getULong()           // READ
           tokenIds(i) = digestsInTx(digestIndex)
           tokenAmounts(i) = amount

data/shared/src/main/scala/sigma/ast/SigmaPredef.scala

@@ -153,7 +153,9 @@ object SigmaPredef {
         { case (_, Seq(arg: EvaluatedValue[SString.type]@unchecked)) =>
           ErgoAddressEncoder(networkPrefix).fromString(arg.value).get match {
             case a: P2PKAddress => SigmaPropConstant(a.pubkey)
-            case a => sys.error(s"unsupported address $a")
+            case a => sys.error(s"The address $a is not supported. " +
+              "Please make sure the address is correct and try again. " +
+              "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
           }
         }),
       OperationInfo(Constant, "",
@@ -165,16 +167,22 @@ object SigmaPredef {
       PredefFuncInfo(
       { case (Ident(_, SFunc(_, tpe, _)), args) =>
         if (args.length != 1)
-          throw new InvalidArguments(s"Wrong number of arguments in $args: expected one argument")
+          throw new InvalidArguments(s"The provided inputs ($args) are incorrect. This operation requires only one input. " +
+            "Please adjust your input to include just one item and try again. " +
+            "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
         val str = args.head match {
           case StringConstant(s) => s
           case _ =>
-            throw new InvalidArguments(s"invalid argument in $args: expected a string constant")
+            throw new InvalidArguments(s"The input provided ($args) is invalid. This operation requires a text value. " +
+              "Please make sure the input is a valid text and try again. " +
+              "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
         }
         val bytes = Base58.decode(str).get
         val res = ValueSerializer.deserialize(bytes)
         if (res.tpe != tpe)
-          throw new InvalidArguments(s"Wrong type after deserialization, expected $tpe, got ${res.tpe}")
+          throw new InvalidArguments(s"The data type is incorrect. Expected: $tpe, but received: ${res.tpe}. " +
+            "Please make sure the data matches the expected type. " +
+            "If the issue keeps happening, contact <a href=\"#\">Customer care</a>.")
         res
       }),
       OperationInfo(Constant, "Deserializes values from Base58 encoded binary data at compile time into a value of type T.",