Add test for in-memory file

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

@@ -1,41 +1,42 @@
 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")
+lazy val assertVirtualFile = taskKey[Unit]("checks source mappers handle virtual files")
+lazy val resetMessages = taskKey[Unit]("empties the messages list")
 
-val assertEmptySourcePositionMappers = taskKey[Unit]("checks that sourcePositionMappers is empty")
-
-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")
-
-assertEmptySourcePositionMappers := {
-  assert {
-    sourcePositionMappers.value.isEmpty
-  }
-}
-
-assertAbsolutePathConversion := {
-  val source = (Compile/sources).value.head
-  assert {
-    FakePrintWriter.messages.exists(_.contains(s"${source.getAbsolutePath}:3:15: comparing values of types Int and String using `==` will always yield false"))
-  }
-  assert {
-    FakePrintWriter.messages.forall(!_.contains("${BASE}"))
-  }
-}
-
-assertVirtualFile := {
-  val source = (Compile/sources).value.head
-  assert {
-    FakePrintWriter.messages.exists(_.contains("${BASE}/src/main/scala/Foo.scala:3:15: comparing values of types Int and String using `==` will always yield false"))
-  }
-  assert {
-    FakePrintWriter.messages.forall(!_.contains(source.getAbsolutePath))
-  }
-}
-
-resetMessages := {
-  FakePrintWriter.resetMessages
-}
+lazy val root = (project in file("."))
+  .settings(
+    extraAppenders := { s => Seq(ConsoleAppender(FakePrintWriter)) },
+    Compile / compile / compileOptions ~= { old: CompileOptions =>
+      old.withSources(StringVirtualFile("<>::A.scala",
+        """object X""") +: old.sources) },
+    assertEmptySourcePositionMappers := {
+      assert {
+        sourcePositionMappers.value.isEmpty
+      }
+    },
+    assertAbsolutePathConversion := {
+      val source = (Compile/sources).value.head
+      assert {
+        FakePrintWriter.messages.exists(_.contains(s"${source.getAbsolutePath}:3:15: comparing values of types Int and String using `==` will always yield false"))
+      }
+      assert {
+        FakePrintWriter.messages.forall(!_.contains("${BASE}"))
+      }
+    },
+    assertVirtualFile := {
+      val source = (Compile/sources).value.head
+      assert {
+        FakePrintWriter.messages.exists(_.contains("${BASE}/src/main/scala/Foo.scala:3:15: comparing values of types Int and String using `==` will always yield false"))
+      }
+      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