All asserts in Quotes should give helpful error messages

[KacperFKorban]

Compiler version

main (3.5.1-RC1-bin-20240628-1efbb92-NIGHTLY)

Minimized example

//> using scala 3.5.1-RC1-bin-20240628-1efbb92-NIGHTLY
// _2.scala

inline def macroWithAssertFailing[T](t: T): Unit = ${ macroWithAssertFailingImpl[T]('t) }

@main
def run =
  macroWithAssertFailing[Int](123)

Comment out the Ref expression and uncomment the TypeIdent one for the second error.

// _1.scala

import scala.quoted.*

def macroWithAssertFailingImpl[T: Type](t: Expr[T])(using Quotes): Expr[Unit] = {
  import quotes.reflect.*

  Ref(TypeRepr.of[T].typeSymbol) // error 1

  // TypeIdent(t.asTerm.symbol) // error 2

  '{()}
}

Output Error/Warning message

Error 1

-- Error: macroasserts/_2.scala:8:29 ----------------------------
8 |  macroWithAssertFailing[Int](123)
  |  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |Exception occurred while executing macro expansion.
  |java.lang.AssertionError: assertion failed
  |	at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:11)
  |	at scala.quoted.runtime.impl.QuotesImpl$reflect$Ref$.apply(QuotesImpl.scala:475)
  |	at scala.quoted.runtime.impl.QuotesImpl$reflect$Ref$.apply(QuotesImpl.scala:474)
  |	at _1$package$.macroWithAssertFailingImpl(_1.scala:8)
  |
  |-----------------------------------------------------------------------------
  |Inline stack trace
  |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  |This location contains code that was inlined from _2.scala:4
4 |inline def macroWithAssertFailing[T](t: T): Unit = ${ macroWithAssertFailingImpl[T]('t) }
  |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   -----------------------------------------------------------------------------

Error 2

-- Error: macroasserts/_2.scala:8:29 ----------------------------
8 |  macroWithAssertFailing[Int](123)
  |  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |Exception occurred while executing macro expansion.
  |java.lang.AssertionError: assertion failed
  |	at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:11)
  |	at scala.quoted.runtime.impl.QuotesImpl$reflect$TypeIdent$.apply(QuotesImpl.scala:1165)
  |	at scala.quoted.runtime.impl.QuotesImpl$reflect$TypeIdent$.apply(QuotesImpl.scala:1164)
  |	at _1$package$.macroWithAssertFailingImpl(_1.scala:10)
  |
  |-----------------------------------------------------------------------------
  |Inline stack trace
  |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  |This location contains code that was inlined from _2.scala:4
4 |inline def macroWithAssertFailing[T](t: T): Unit = ${ macroWithAssertFailingImpl[T]('t) }
  |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   -----------------------------------------------------------------------------

Why this Error/Warning was not helpful

The assert should provide a useful message about why it failed.

Asserts in Quotes that are missing messages:

• scala3/compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala

  Line 475 in 0e60d36

  assert(sym.isTerm)

• scala3/compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala

  Line 1165 in 0e60d36

  assert(sym.isType)

It might also be useful to check other assert messages if they can be improved.