#1579 Adapt the sbt bridge for the new error message

1 files changed, 111 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/reporting/MessageRendering.scala b/src/dotty/tools/dotc/reporting/MessageRendering.scala
new file mode 100644
index 000000000..6d9e45a6e
--- /dev/null
+++ b/src/dotty/tools/dotc/reporting/MessageRendering.scala
@@ -0,0 +1,111 @@
+package dotty.tools
+package dotc
+package reporting
+
+import core.Contexts.Context
+import core.Decorators._
+import printing.Highlighting.{Blue, Red}
+import diagnostic.{Message, MessageContainer, NoExplanation}
+import diagnostic.messages._
+import util.SourcePosition
+
+import scala.collection.mutable
+
+trait MessageRendering {
+  def stripColor(str: String): String =
+    str.replaceAll("\u001B\\[[;\\d]*m", "")
+
+  def sourceLines(pos: SourcePosition)(implicit ctx: Context): (List[String], List[String], Int) = {
+    var maxLen = Int.MinValue
+    def render(xs: List[Int]) =
+      xs.map(pos.source.offsetToLine(_))
+        .map { lineNbr =>
+          val prefix = s"${lineNbr + 1} |"
+          maxLen = math.max(maxLen, prefix.length)
+          (prefix, pos.lineContent(lineNbr).stripLineEnd)
+        }
+        .map { case (prefix, line) =>
+          val lnum = Red(" " * math.max(0, maxLen - prefix.length) + prefix)
+          hl"$lnum$line"
+        }
+
+    val (before, after) = pos.beforeAndAfterPoint
+    (render(before), render(after), maxLen)
+  }
+
+  def columnMarker(pos: SourcePosition, offset: Int)(implicit ctx: Context): String = {
+    val prefix = " " * (offset - 1)
+    val whitespace = " " * pos.startColumn
+    val carets = Red {
+      if (pos.startLine == pos.endLine)
+        "^" * math.max(1, pos.endColumn - pos.startColumn)
+      else "^"
+    }
+
+    s"$prefix|$whitespace${carets.show}"
+  }
+
+  def errorMsg(pos: SourcePosition, msg: String, offset: Int)(implicit ctx: Context): String = {
+    val leastWhitespace = msg.lines.foldLeft(Int.MaxValue) { (minPad, line) =>
+      val lineLength = stripColor(line).length
+      val padding =
+        math.min(math.max(0, ctx.settings.pageWidth.value - offset - lineLength), offset + pos.startColumn)
+
+      if (padding < minPad) padding
+      else minPad
+    }
+
+    msg.lines
+      .map { line => " " * (offset - 1) + "|" + (" " * (leastWhitespace - offset)) + line }
+      .mkString(sys.props("line.separator"))
+  }
+
+  def posStr(pos: SourcePosition, diagnosticLevel: String, message: Message)(implicit ctx: Context): String =
+    if (pos.exists) Blue({
+      val file = pos.source.file.toString
+      val errId =
+        if (message.errorId != NoExplanation.ID)
+          s"[E${"0" * (3 - message.errorId.toString.length) + message.errorId}] "
+        else ""
+      val kind =
+        if (message.kind == "") diagnosticLevel
+        else s"${message.kind} $diagnosticLevel"
+      val prefix = s"-- ${errId}${kind}: $file "
+
+      prefix +
+        ("-" * math.max(ctx.settings.pageWidth.value - stripColor(prefix).length, 0))
+    }).show else ""
+
+  def explanation(m: Message)(implicit ctx: Context): String = {
+    val sb = new StringBuilder(hl"""|
+                                    |${Blue("Explanation")}
+                                    |${Blue("===========")}""".stripMargin)
+    sb.append('\n').append(m.explanation)
+    if (m.explanation.lastOption != Some('\n')) sb.append('\n')
+    sb.toString
+  }
+
+  def messageAndPos(msg: Message, pos: SourcePosition, diagnosticLevel: String)(implicit ctx: Context): String = {
+    val sb = mutable.StringBuilder.newBuilder
+    sb.append(posStr(pos, diagnosticLevel, msg)).append('\n')
+    if (pos.exists) {
+      val (srcBefore, srcAfter, offset) = sourceLines(pos)
+      val marker = columnMarker(pos, offset)
+      val err = errorMsg(pos, msg.msg, offset)
+      sb.append((srcBefore ::: marker :: err :: srcAfter).mkString("\n"))
+    } else sb.append(msg.msg)
+    sb.toString
+  }
+
+  def diagnosticLevel(cont: MessageContainer): String = {
+    cont match {
+      case m: Error => "Error"
+      case m: FeatureWarning => "Feature Warning"
+      case m: DeprecationWarning => "Deprecation Warning"
+      case m: UncheckedWarning => "Unchecked Warning"
+      case m: MigrationWarning => "Migration Warning"
+      case m: Warning => "Warning"
+      case m: Info => "Info"
+    }
+  }
+}