Symbol.docString not available in tests

[OndrejSpanel]

Using Symbol.docstring from tests to inspect types defined in main always returns None.

Compiler version

3.3.3
3.4.1

Minimized code

https://github.com/OndrejSpanel/Scala3-DocStringInTest

main:

import scala.quoted.*

object Doc {
  inline def of[A]: Option[String] = ${ ofImpl[A] }

  def ofImpl[A: Type](using Quotes): Expr[Option[String]] = {
    import quotes.reflect.*

    val symbol = TypeRepr.of[A].typeSymbol
    Expr(symbol.docstring)
  }
}

/**
 * my doc string for Main
 *
 * @param tracks track listing
 * */

class Main(tracks: String)

object Main {
  def main(args: Array[String]): Unit = {
    val docString = Doc.of[Main]
    println(docString)
  }
}

test:

/**
 * Doc of Test
 * */
class Test

object Test {
  def main(args: Array[String]): Unit = {
    val docString = Doc.of[Main]
    println(docString)
    val docStringTest = Doc.of[Test]
    println(docStringTest)

    if (docString.isEmpty || docStringTest.isEmpty) System.exit(1)
  }
}

Use Test/run to run the code.

Output

Workflow output:

None
Some(/**
 * Doc of Test
 * */)

Note: while test can access values of docstring defined in test. it cannot access any docstring defined in main, it always gets None.

Expectation

The docstring values of symbols defined in the main should be available from tests.

[nicolasstucki]

What is the definition of Main?

[OndrejSpanel]

Added. Getting docstring of Main works fine from main sources, not from test.

Complete project is linked in the issue, as well as the workflow output demonstrating the failure.

[nicolasstucki]

It seems that we are not loading the docstrings from TASTy. This can be enabled with -Yread-docs, but users should not use that. The ContextDocstrings should be able to load documentation on demand.

[OndrejSpanel]

Glad to hear you are making progress on this.

What is the difference between loading main and test docstrings from test? Because main from main works, as well as test from test. Are they read from other place than TASTy in such case?

[nicolasstucki]

What is the difference between loading main and test docstrings from test? Because main from main works, as well as test from test. Are they read from other place than TASTy in such case?

In that case, they come directly from the parsed source file. You may also be missing the documentation if there is an incremental compilation and part of the files are related from TASTy from the previous compilation.

[OndrejSpanel]

The same issue happens when reading ScalaDoc from other modules, which given the issue cause is understandable. The workaround in this case is to use scalacOptions += "-Yread-docs" in the module reading the docs.