Avoid NoMatchError in IDE

odersky · odersky · commit 659ab0becaa1 · 2018-03-09T14:53:54.000+01:00
I observed a NoType when editing some code which caused ThisType#underlying to crash.
diff --git a/compiler/src/dotty/tools/dotc/core/Types.scala b/compiler/src/dotty/tools/dotc/core/Types.scala
@@ -2184,7 +2184,7 @@ object Types {
       if (ctx.erasedTypes) tref
       else cls.info match {
         case cinfo: ClassInfo => cinfo.selfType
-        case cinfo: ErrorType if ctx.mode.is(Mode.Interactive) => cinfo
+        case _: ErrorType | NoType if ctx.mode.is(Mode.Interactive) => cls.info
           // can happen in IDE if `cls` is stale
       }
 

Original file line number	Diff line number	Diff line change
`@@ -2184,7 +2184,7 @@ object Types {`
`2184`	`2184`	`if (ctx.erasedTypes) tref`
`2185`	`2185`	`else cls.info match {`
`2186`	`2186`	`case cinfo: ClassInfo => cinfo.selfType`
`2187`		`- case cinfo: ErrorType if ctx.mode.is(Mode.Interactive) => cinfo`
	`2187`	`+ case _: ErrorType \| NoType if ctx.mode.is(Mode.Interactive) => cls.info`
`2188`	`2188`	// can happen in IDE if `cls` is stale
`2189`	`2189`	`}`
`2190`	`2190`