First string part of interpolation is mispositioned

[martijnhoekstra]

minimized code

package dotty.tools
package dotc
package parsing

import ast.untpd._
import org.junit.Test

class PositionTest extends ParserTest {

  val tq = "\"\"\""
  val program = s"""
    |class A {
    |  val expr = 42
    |  val s0 = s"string1"
    |  val s1 = s"string1$${expr}string2"
    |  val s2 = s"string1$${expr}string2$${expr}string3"
    |  val s0m = s${tq}string1${tq}
    |  val s1m = s${tq}string1$${expr}string2${tq}
    |  val s2m = s${tq}string1$${expr}string2$${expr}string3${tq}
    |}""".stripMargin

  @Test
  def interpolationLiteralPosition: Unit = {
    val t = parseText(program)
    t match {
      case PackageDef(_, List(TypeDef(_, Template(_, _, _, statements: List[Tree])))) => {
        val interpolations = statements.collect{ case ValDef(_, _, InterpolatedString(_, int)) => int }
        val lits = interpolations.flatten.flatMap {
          case l @ Literal(_) => List(l)
          case Thicket(trees) => trees.collect { case l @ Literal(_) => l }
        }
        for {
          lit <- lits
          Literal(c) = lit
          str <- List(c.value).collect { case str: String => str}
        } {
          val fromPos = program.substring(lit.span.start, lit.span.end)
          assert(fromPos == str, s"$fromPos == $str")
        }
      }
    }
  }
}

Compilation output

[info] Compiling 1 Scala source to /home/martijn/dotty/compiler/target/scala-0.24/test-classes ...

expectation

Position of the string literal parts coincides with the actual source position.

[smarter]

[info] Compiling 1 Scala source to /home/martijn/dotty/compiler/target/scala-0.24/test-classes ...

Did you mean to paste the test output here ?

[martijnhoekstra]

No, that's compilation output

[smarter]

I mean sure, but it's not very useful here :). You don't have to follow rigidly the issue template if there's some other useful information you can provide.

[martijnhoekstra]

More information: the tree is mispositioned for interpolators that don't actually interpolate stuff, s"foo$bar" is unaffected. The string is mispositioned with the correct length at the first quote, so offset by 1 for a single quoted interpolation, and offset by 3 for a triple quoted interpolation.