Add test for in-memory file

sbt/src/sbt-test/reporter/source-mapper/build.sbt

@@ -1,21 +1,23 @@
 import sbt.internal.util.ConsoleAppender
+import sbt.internal.inc.StringVirtualFile
+import xsbti.compile.CompileOptions
 
-extraAppenders := { s => Seq(ConsoleAppender(FakePrintWriter)) }
+lazy val assertEmptySourcePositionMappers = taskKey[Unit]("checks that sourcePositionMappers is empty")
-
+lazy val assertAbsolutePathConversion = taskKey[Unit]("checks source mappers convert to absolute path")
-val assertEmptySourcePositionMappers = taskKey[Unit]("checks that sourcePositionMappers is empty")
+lazy val assertVirtualFile = taskKey[Unit]("checks source mappers handle virtual files")
-
+lazy val resetMessages = taskKey[Unit]("empties the messages list")
-val assertAbsolutePathConversion = taskKey[Unit]("checks source mappers convert to absolute path")
-
-val assertVirtualFile = taskKey[Unit]("checks source mappers handle virtual files")
-
-val resetMessages = taskKey[Unit]("empties the messages list")
 
+lazy val root = (project in file("."))
+  .settings(
+    extraAppenders := { s => Seq(ConsoleAppender(FakePrintWriter)) },
+    Compile / compile / compileOptions ~= { old: CompileOptions =>
+      old.withSources(StringVirtualFile("<>::A.scala",
+        """object X""") +: old.sources) },
     assertEmptySourcePositionMappers := {
       assert {
         sourcePositionMappers.value.isEmpty
       }
-}
+    },
-
     assertAbsolutePathConversion := {
       val source = (Compile/sources).value.head
       assert {
@@ -24,8 +26,7 @@ assertAbsolutePathConversion := {
       assert {
         FakePrintWriter.messages.forall(!_.contains("${BASE}"))
       }
-}
+    },
-
     assertVirtualFile := {
       val source = (Compile/sources).value.head
       assert {
@@ -34,8 +35,8 @@ assertVirtualFile := {
       assert {
         FakePrintWriter.messages.forall(!_.contains(source.getAbsolutePath))
       }
-}
+    },
-
     resetMessages := {
       FakePrintWriter.resetMessages
     }
+  )

sbt/src/sbt-test/reporter/source-mapper/test

@@ -1,3 +1,5 @@
+> compile
+
 > assertEmptySourcePositionMappers
 
 > printWarnings