REPL crashes at completion if type parameter is omitted

[ansvonwa]

Compiler version

3.0.0

Minimized code

scala> ???.asInstanceOf[scala.collection.Seq].<tab>

Note:

• The type parameter of s.c.Seq is omitted (Repl does not crash if it is given)
• The REPL does not crash if the type alias from Predef is used instead (Seq instead of scala.collection.Seq)
• The <tab> means that the tab key is pressed for completion after the ..
• May be related to Compiler freezes if type parameter is omitted #12466

Output (click arrow to expand)

An AssertionError occurs and the REPL exits

Exception in thread "main" java.lang.AssertionError: assertion failed: found: ???.asInstanceOf[scala.collection.Seq]: collection.Seq, expected: Any
	at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:8)
	at dotty.tools.dotc.typer.Implicits$ImplicitSearch.<init>(Implicits.scala:1091)
	at dotty.tools.dotc.interactive.Completion$Completer.implicitConversionTargets(Completion.scala:413)
	at dotty.tools.dotc.interactive.Completion$Completer.implicitConversionMemberCompletions(Completion.scala:301)
	at dotty.tools.dotc.interactive.Completion$Completer.selectionCompletions(Completion.scala:242)
	at dotty.tools.dotc.interactive.Completion$.computeCompletions(Completion.scala:115)
	at dotty.tools.dotc.interactive.Completion$.completions(Completion.scala:49)
	at dotty.tools.repl.ReplDriver.completions$$anonfun$1(ReplDriver.scala:203)
	at scala.util.Either.map(Either.scala:382)
	at dotty.tools.repl.ReplDriver.completions(ReplDriver.scala:204)
	at dotty.tools.repl.ReplDriver.$anonfun$3(ReplDriver.scala:128)
	at org.jline.reader.impl.LineReaderImpl.doComplete(LineReaderImpl.java:4412)
	at org.jline.reader.impl.LineReaderImpl.doComplete(LineReaderImpl.java:4378)
	at org.jline.reader.impl.LineReaderImpl.expandOrComplete(LineReaderImpl.java:4317)
	at org.jline.reader.impl.LineReaderImpl$1.apply(LineReaderImpl.java:3809)
	at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:679)
	at org.jline.reader.impl.LineReaderImpl.readLine(LineReaderImpl.java:468)
	at dotty.tools.repl.JLineTerminal.readLine(JLineTerminal.scala:72)
	at dotty.tools.repl.ReplDriver.readLine$1(ReplDriver.scala:133)
	at dotty.tools.repl.ReplDriver.loop$1(ReplDriver.scala:143)
	at dotty.tools.repl.ReplDriver.runUntilQuit$$anonfun$1(ReplDriver.scala:148)
	at dotty.tools.repl.ReplDriver.withRedirectedOutput(ReplDriver.scala:167)
	at dotty.tools.repl.ReplDriver.runUntilQuit(ReplDriver.scala:148)
	at dotty.tools.repl.ReplDriver.tryRunning(ReplDriver.scala:114)
	at dotty.tools.repl.Main$.main(Main.scala:6)
	at dotty.tools.repl.Main.main(Main.scala)

[bishabosha]

maybe this is fixed by #13368?

[SethTisue]

no such luck, it still crashes even on current master

Exception in thread "main" java.lang.AssertionError: assertion failed: found: ???.asInstanceOf[scala.collection.Seq]: collection.Seq, expected: Any
	at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:8)
	at dotty.tools.dotc.typer.Implicits$ImplicitSearch.<init>(Implicits.scala:1110)
	at dotty.tools.dotc.interactive.Completion$Completer.implicitConversionTargets(Completion.scala:396)
	at dotty.tools.dotc.interactive.Completion$Completer.implicitConversionMemberCompletions(Completion.scala:283)
	at dotty.tools.dotc.interactive.Completion$Completer.selectionCompletions(Completion.scala:224)
	at dotty.tools.dotc.interactive.Completion$.computeCompletions(Completion.scala:118)
	at dotty.tools.dotc.interactive.Completion$.completions(Completion.scala:49)
	at dotty.tools.repl.ReplDriver.completions$$anonfun$1(ReplDriver.scala:210)
	at scala.util.Either.map(Either.scala:382)
	at dotty.tools.repl.ReplDriver.completions(ReplDriver.scala:211)
	at dotty.tools.repl.ReplDriver.$anonfun$3(ReplDriver.scala:136)
	at org.jline.reader.impl.LineReaderImpl.doComplete(LineReaderImpl.java:4412)