diff --git a/compiler/test/dotc/tests.scala b/compiler/test/dotc/tests.scala
index c626f0d80976..6de3a86d2054 100644
--- a/compiler/test/dotc/tests.scala
+++ b/compiler/test/dotc/tests.scala
@@ -186,7 +186,7 @@ class tests extends CompilerTest {
 
   @Test def negVarargsT1625 = compileFiles(negDir + "varargsInMethodsT1625/")
 
-  val negCustomArgs = negDir + "customArgs/"
+  val negCustomArgs = testsDir + "neg-custom-args/"
 
   @Test def neg_typers() = compileFile(negCustomArgs, "typers")(allowDoubleBindings)
   @Test def neg_overrideClass = compileFile(negCustomArgs, "overrideClass", scala2mode)
@@ -198,7 +198,7 @@ class tests extends CompilerTest {
   @Test def neg_valueclasses_pavlov = compileFile(negCustomArgs, "valueclasses-pavlov")(allowDoubleBindings)
   @Test def neg_trailingUnderscore = compileFile(negCustomArgs, "trailingUnderscore", args = "-strict" :: Nil)
 
-  val negTailcallDir = negDir + "tailcall/"
+  val negTailcallDir = testsDir + "neg-tailcall/"
   @Test def neg_tailcall_t1672b = compileFile(negTailcallDir, "t1672b")
   @Test def neg_tailcall_t3275 = compileFile(negTailcallDir, "t3275")
   @Test def neg_tailcall_t6574 = compileFile(negTailcallDir, "t6574")
diff --git a/compiler/test/dotty/tools/dotc/CompilationTests.scala b/compiler/test/dotty/tools/dotc/CompilationTests.scala
index 8326468c5ffa..e1057838ddbe 100644
--- a/compiler/test/dotty/tools/dotc/CompilationTests.scala
+++ b/compiler/test/dotty/tools/dotc/CompilationTests.scala
@@ -99,7 +99,7 @@ class CompilationTests extends ParallelTesting {
     compileDir("../tests/pos/i1137-1", defaultOptions and "-Yemit-tasty") +
     compileFile(
       // succeeds despite -Xfatal-warnings because of -nowarn
-      "../tests/neg/customArgs/xfatalWarnings.scala",
+      "../tests/neg-custom-args/xfatalWarnings.scala",
       defaultOptions.and("-nowarn", "-Xfatal-warnings")
     )
   }.checkCompile()
@@ -165,30 +165,25 @@ class CompilationTests extends ParallelTesting {
 
   @Test def compileNeg: Unit = {
     implicit val testGroup: TestGroup = TestGroup("compileNeg")
-    compileShallowFilesInDir("../tests/neg", defaultOptions) +
-    compileShallowFilesInDir("../tests/neg/no-optimise", defaultOptions) +
-    compileFile("../tests/neg/customArgs/typers.scala", allowDoubleBindings) +
-    compileFile("../tests/neg/customArgs/overrideClass.scala", scala2Mode) +
-    compileFile("../tests/neg/customArgs/autoTuplingTest.scala", defaultOptions.and("-language:noAutoTupling")) +
-    compileFile("../tests/neg/customArgs/i1050.scala", defaultOptions.and("-strict")) +
-    compileFile("../tests/neg/customArgs/i1240.scala", allowDoubleBindings) +
-    compileFile("../tests/neg/customArgs/i2002.scala", allowDoubleBindings) +
-    compileFile("../tests/neg/customArgs/nopredef.scala", defaultOptions.and("-Yno-predef")) +
-    compileFile("../tests/neg/customArgs/noimports.scala", defaultOptions.and("-Yno-imports")) +
-    compileFile("../tests/neg/customArgs/noimports2.scala", defaultOptions.and("-Yno-imports")) +
-    compileFile("../tests/neg/customArgs/overloadsOnAbstractTypes.scala", allowDoubleBindings) +
-    compileFile("../tests/neg/customArgs/xfatalWarnings.scala", defaultOptions.and("-Xfatal-warnings")) +
-    compileFile("../tests/neg/customArgs/pureStatement.scala", defaultOptions.and("-Xfatal-warnings")) +
-    compileFile("../tests/neg/customArgs/phantom-overload.scala", allowDoubleBindings) +
-    compileFile("../tests/neg/customArgs/phantom-overload-2.scala", allowDoubleBindings) +
-    compileFile("../tests/neg/tailcall/t1672b.scala", defaultOptions) +
-    compileFile("../tests/neg/tailcall/t3275.scala", defaultOptions) +
-    compileFile("../tests/neg/tailcall/t6574.scala", defaultOptions) +
-    compileFile("../tests/neg/tailcall/tailrec.scala", defaultOptions) +
-    compileFile("../tests/neg/tailcall/tailrec-2.scala", defaultOptions) +
-    compileFile("../tests/neg/tailcall/tailrec-3.scala", defaultOptions) +
-    compileFile("../tests/neg/i3246.scala", scala2Mode) +
-    compileDir("../tests/neg/typedIdents", defaultOptions)
+    compileFilesInDir("../tests/neg", defaultOptions) +
+    compileFilesInDir("../tests/neg-tailcall", defaultOptions) +
+    compileFilesInDir("../tests/neg-no-optimise", defaultOptions) +
+    compileFile("../tests/neg-custom-args/i3246.scala", scala2Mode) +
+    compileFile("../tests/neg-custom-args/typers.scala", allowDoubleBindings) +
+    compileFile("../tests/neg-custom-args/overrideClass.scala", scala2Mode) +
+    compileFile("../tests/neg-custom-args/autoTuplingTest.scala", defaultOptions.and("-language:noAutoTupling")) +
+    compileFile("../tests/neg-custom-args/i1050.scala", defaultOptions.and("-strict")) +
+    compileFile("../tests/neg-custom-args/i1240.scala", allowDoubleBindings) +
+    compileFile("../tests/neg-custom-args/i2002.scala", allowDoubleBindings) +
+    compileFile("../tests/neg-custom-args/nopredef.scala", defaultOptions.and("-Yno-predef")) +
+    compileFile("../tests/neg-custom-args/noimports.scala", defaultOptions.and("-Yno-imports")) +
+    compileFile("../tests/neg-custom-args/noimports2.scala", defaultOptions.and("-Yno-imports")) +
+    compileFile("../tests/neg-custom-args/overloadsOnAbstractTypes.scala", allowDoubleBindings) +
+    compileFile("../tests/neg-custom-args/xfatalWarnings.scala", defaultOptions.and("-Xfatal-warnings")) +
+    compileFile("../tests/neg-custom-args/pureStatement.scala", defaultOptions.and("-Xfatal-warnings")) +
+    compileFile("../tests/neg-custom-args/phantom-overload.scala", allowDoubleBindings) +
+    compileFile("../tests/neg-custom-args/phantom-overload-2.scala", allowDoubleBindings) +
+    compileFile("../tests/neg-custom-args/structural.scala", defaultOptions.and("-Xfatal-warnings"))
   }.checkExpectedErrors()
 
   // Run tests -----------------------------------------------------------------
@@ -311,7 +306,7 @@ class CompilationTests extends ParallelTesting {
     implicit val testGroup: TestGroup = TestGroup("optimised/testOptimised")
     compileFilesInDir("../tests/pos", defaultOptimised).checkCompile()
     compileFilesInDir("../tests/run", defaultOptimised).checkRuns()
-    compileShallowFilesInDir("../tests/neg", defaultOptimised).checkExpectedErrors()
+    compileFilesInDir("../tests/neg", defaultOptimised).checkExpectedErrors()
   }
 
   private val (compilerSources, backendSources, backendJvmSources) = {
@@ -340,10 +335,14 @@ object CompilationTests {
   implicit val summaryReport: SummaryReporting = new SummaryReport
   @AfterClass def cleanup(): Unit = summaryReport.echoSummary()
 
-  def sources(paths: JStream[Path], excludedFiles: List[String] = Nil): List[String] =
-    paths.iterator().asScala
+  def sources(paths: JStream[Path], excludedFiles: List[String] = Nil): List[String] = {
+    val sources = paths.iterator().asScala
       .filter(path =>
         (path.toString.endsWith(".scala") || path.toString.endsWith(".java"))
           && !excludedFiles.contains(path.getFileName.toString))
       .map(_.toString).toList
+
+    paths.close()
+    sources
+  }
 }
diff --git a/compiler/test/dotty/tools/dotc/CompilerTest.scala b/compiler/test/dotty/tools/dotc/CompilerTest.scala
index 888b20f69efa..d6c2bbbc80f1 100644
--- a/compiler/test/dotty/tools/dotc/CompilerTest.scala
+++ b/compiler/test/dotty/tools/dotc/CompilerTest.scala
@@ -149,7 +149,8 @@ abstract class CompilerTest {
 
   private def expectedErrors(filePath: String): List[ErrorsInFile] = expectedErrors(List(filePath))
 
-  private def isNegTest(testPath: String) = testPath.contains("/neg/")
+  private def isNegTest(testPath: String) =
+    testPath.contains("/neg/") || testPath.contains("/neg-custom-args/") || testPath.contains("/neg-tailcall/")
 
   private def compileArgs(args: Array[String], expectedErrorsPerFile: List[ErrorsInFile])
       (implicit defaultOptions: List[String]): Unit = {
diff --git a/compiler/test/dotty/tools/dotc/MissingCoreLibTests.scala b/compiler/test/dotty/tools/dotc/MissingCoreLibTests.scala
index 31c7197ad498..bf50c6f3d6ad 100644
--- a/compiler/test/dotty/tools/dotc/MissingCoreLibTests.scala
+++ b/compiler/test/dotty/tools/dotc/MissingCoreLibTests.scala
@@ -11,7 +11,7 @@ class MissingCoreLibTests {
 
   @Test def missingDottyLib: Unit = {
     val classPath = mkClassPath(Jars.dottyCompiler :: Jars.dottyInterfaces :: Jars.dottyExtras) // missing Jars.dottyLib
-    val source = "../tests/neg/nolib/Foo.scala"
+    val source = "../tests/pos/Foo.scala"
     val options = Array("-classpath", classPath, source)
     val reporter = Main.process(options)
     assertEquals(1, reporter.errorCount)
diff --git a/compiler/test/dotty/tools/dotc/SettingsTests.scala b/compiler/test/dotty/tools/dotc/SettingsTests.scala
index b1fffbabda44..1742e9e93d25 100644
--- a/compiler/test/dotty/tools/dotc/SettingsTests.scala
+++ b/compiler/test/dotty/tools/dotc/SettingsTests.scala
@@ -19,7 +19,7 @@ class SettingsTests {
 
   @Test def jarOutput: Unit = {
     val classPath = mkClassPath(Jars.dottyTestDeps)
-    val source = "../tests/neg/nolib/Foo.scala"
+    val source = "../tests/pos/Foo.scala"
     val out = Paths.get("../out/jaredFoo.jar").normalize
     if (Files.exists(out)) Files.delete(out)
     val options = Array("-classpath", classPath, "-d", out.toString, source)
diff --git a/tests/neg/customArgs/autoTuplingTest.scala b/tests/neg-custom-args/autoTuplingTest.scala
similarity index 100%
rename from tests/neg/customArgs/autoTuplingTest.scala
rename to tests/neg-custom-args/autoTuplingTest.scala
diff --git a/tests/neg/customArgs/i1050.scala b/tests/neg-custom-args/i1050.scala
similarity index 100%
rename from tests/neg/customArgs/i1050.scala
rename to tests/neg-custom-args/i1050.scala
diff --git a/tests/neg/customArgs/i1240.scala b/tests/neg-custom-args/i1240.scala
similarity index 100%
rename from tests/neg/customArgs/i1240.scala
rename to tests/neg-custom-args/i1240.scala
diff --git a/tests/neg/customArgs/i2002.scala b/tests/neg-custom-args/i2002.scala
similarity index 100%
rename from tests/neg/customArgs/i2002.scala
rename to tests/neg-custom-args/i2002.scala
diff --git a/tests/neg/i3246.scala b/tests/neg-custom-args/i3246.scala
similarity index 100%
rename from tests/neg/i3246.scala
rename to tests/neg-custom-args/i3246.scala
diff --git a/tests/neg/customArgs/noimports.scala b/tests/neg-custom-args/noimports.scala
similarity index 100%
rename from tests/neg/customArgs/noimports.scala
rename to tests/neg-custom-args/noimports.scala
diff --git a/tests/neg/customArgs/noimports2.scala b/tests/neg-custom-args/noimports2.scala
similarity index 100%
rename from tests/neg/customArgs/noimports2.scala
rename to tests/neg-custom-args/noimports2.scala
diff --git a/tests/neg/customArgs/nopredef.scala b/tests/neg-custom-args/nopredef.scala
similarity index 100%
rename from tests/neg/customArgs/nopredef.scala
rename to tests/neg-custom-args/nopredef.scala
diff --git a/tests/neg/customArgs/overloadsOnAbstractTypes.scala b/tests/neg-custom-args/overloadsOnAbstractTypes.scala
similarity index 100%
rename from tests/neg/customArgs/overloadsOnAbstractTypes.scala
rename to tests/neg-custom-args/overloadsOnAbstractTypes.scala
diff --git a/tests/neg/customArgs/overrideClass.scala b/tests/neg-custom-args/overrideClass.scala
similarity index 100%
rename from tests/neg/customArgs/overrideClass.scala
rename to tests/neg-custom-args/overrideClass.scala
diff --git a/tests/neg/customArgs/phantom-overload-2.scala b/tests/neg-custom-args/phantom-overload-2.scala
similarity index 100%
rename from tests/neg/customArgs/phantom-overload-2.scala
rename to tests/neg-custom-args/phantom-overload-2.scala
diff --git a/tests/neg/customArgs/phantom-overload.scala b/tests/neg-custom-args/phantom-overload.scala
similarity index 100%
rename from tests/neg/customArgs/phantom-overload.scala
rename to tests/neg-custom-args/phantom-overload.scala
diff --git a/tests/neg/customArgs/pureStatement.scala b/tests/neg-custom-args/pureStatement.scala
similarity index 100%
rename from tests/neg/customArgs/pureStatement.scala
rename to tests/neg-custom-args/pureStatement.scala
diff --git a/tests/neg/compExceptions/structural.scala b/tests/neg-custom-args/structural.scala
similarity index 68%
rename from tests/neg/compExceptions/structural.scala
rename to tests/neg-custom-args/structural.scala
index 1d25062909f3..6cc2c5be7e33 100644
--- a/tests/neg/compExceptions/structural.scala
+++ b/tests/neg-custom-args/structural.scala
@@ -1,3 +1,5 @@
+import scala.reflect.Selectable.reflectiveSelectable
+
 package p1 {
 
 object test123 {
@@ -36,12 +38,13 @@ object RClose {
 }
 
 package p3 {
+
 object Test {
-  def idMap[C[_],T](m: { def map[U](f: T => U): C[U] }): C[T] = m.map(t => t)
+  def idMap[C[_],T](m: { def map[U](f: T => U): C[U] }): C[T] = m.map(t => t) // error: polymorphic refinement method map without matching type in parent Object is no longer allowed
 
   def main(args: Array[String]): Unit = {
-    idMap(Some(5))
-    idMap(Responder.constant(5))
+    idMap(Some(5)) // error: type mismatch: found Some[Int], required Object{map: [U](f: Any => U): Any}
+    idMap(Responder.constant(5)) // error: type mismatch: found Responder[Int], required Object{map: [U](f: Any => U): Any}
   }
 }
 }
@@ -49,7 +52,7 @@ package p4 {
 
 trait A { self: Any { def p: Any } =>
   def f(b: => Unit): Unit = {}
-  f { p } // error: cannot access member 'p' from structural type
+  f { p } // OK
 }
 }
 
@@ -64,7 +67,7 @@ object Test {
 package p6 {
 
   class Refinements {
-    val y: C { val x: T; type T }  // was adeprecated warning: illegal forward reference in refinement; now illegal
+    val y: { val x: T; type T }  // error: deprecated warning: illegal forward reference in refinement; now illegal
   }
 
 }
diff --git a/tests/neg/customArgs/trailingUnderscore.scala b/tests/neg-custom-args/trailingUnderscore.scala
similarity index 100%
rename from tests/neg/customArgs/trailingUnderscore.scala
rename to tests/neg-custom-args/trailingUnderscore.scala
diff --git a/tests/neg/customArgs/typers.scala b/tests/neg-custom-args/typers.scala
similarity index 100%
rename from tests/neg/customArgs/typers.scala
rename to tests/neg-custom-args/typers.scala
diff --git a/tests/neg/customArgs/valueclasses-doubledefs.scala b/tests/neg-custom-args/valueclasses-doubledefs.scala
similarity index 100%
rename from tests/neg/customArgs/valueclasses-doubledefs.scala
rename to tests/neg-custom-args/valueclasses-doubledefs.scala
diff --git a/tests/neg/customArgs/valueclasses-pavlov.scala b/tests/neg-custom-args/valueclasses-pavlov.scala
similarity index 100%
rename from tests/neg/customArgs/valueclasses-pavlov.scala
rename to tests/neg-custom-args/valueclasses-pavlov.scala
diff --git a/tests/neg/customArgs/xfatalWarnings.scala b/tests/neg-custom-args/xfatalWarnings.scala
similarity index 100%
rename from tests/neg/customArgs/xfatalWarnings.scala
rename to tests/neg-custom-args/xfatalWarnings.scala
diff --git a/tests/neg/no-optimise/patmat.scala b/tests/neg-no-optimise/patmat1.scala
similarity index 100%
rename from tests/neg/no-optimise/patmat.scala
rename to tests/neg-no-optimise/patmat1.scala
diff --git a/tests/neg/no-optimise/tryPatternMatchError.scala b/tests/neg-no-optimise/patmat2.scala
similarity index 100%
rename from tests/neg/no-optimise/tryPatternMatchError.scala
rename to tests/neg-no-optimise/patmat2.scala
diff --git a/tests/neg/tailcall/i1221.scala b/tests/neg-tailcall/i1221.scala
similarity index 100%
rename from tests/neg/tailcall/i1221.scala
rename to tests/neg-tailcall/i1221.scala
diff --git a/tests/neg/tailcall/i1221b.scala b/tests/neg-tailcall/i1221b.scala
similarity index 100%
rename from tests/neg/tailcall/i1221b.scala
rename to tests/neg-tailcall/i1221b.scala
diff --git a/tests/neg/tailcall/t1672b.check b/tests/neg-tailcall/t1672b.check
similarity index 100%
rename from tests/neg/tailcall/t1672b.check
rename to tests/neg-tailcall/t1672b.check
diff --git a/tests/neg/tailcall/t1672b.scala b/tests/neg-tailcall/t1672b.scala
similarity index 100%
rename from tests/neg/tailcall/t1672b.scala
rename to tests/neg-tailcall/t1672b.scala
diff --git a/tests/neg/tailcall/t3275.check b/tests/neg-tailcall/t3275.check
similarity index 100%
rename from tests/neg/tailcall/t3275.check
rename to tests/neg-tailcall/t3275.check
diff --git a/tests/neg/tailcall/t3275.scala b/tests/neg-tailcall/t3275.scala
similarity index 100%
rename from tests/neg/tailcall/t3275.scala
rename to tests/neg-tailcall/t3275.scala
diff --git a/tests/neg/tailcall/t6574.check b/tests/neg-tailcall/t6574.check
similarity index 100%
rename from tests/neg/tailcall/t6574.check
rename to tests/neg-tailcall/t6574.check
diff --git a/tests/neg/tailcall/t6574.scala b/tests/neg-tailcall/t6574.scala
similarity index 100%
rename from tests/neg/tailcall/t6574.scala
rename to tests/neg-tailcall/t6574.scala
diff --git a/tests/neg/tailcall/tailrec-2.check b/tests/neg-tailcall/tailrec-2.check
similarity index 100%
rename from tests/neg/tailcall/tailrec-2.check
rename to tests/neg-tailcall/tailrec-2.check
diff --git a/tests/neg/tailcall/tailrec-2.scala b/tests/neg-tailcall/tailrec-2.scala
similarity index 100%
rename from tests/neg/tailcall/tailrec-2.scala
rename to tests/neg-tailcall/tailrec-2.scala
diff --git a/tests/neg/tailcall/tailrec-3.check b/tests/neg-tailcall/tailrec-3.check
similarity index 100%
rename from tests/neg/tailcall/tailrec-3.check
rename to tests/neg-tailcall/tailrec-3.check
diff --git a/tests/neg/tailcall/tailrec-3.scala b/tests/neg-tailcall/tailrec-3.scala
similarity index 100%
rename from tests/neg/tailcall/tailrec-3.scala
rename to tests/neg-tailcall/tailrec-3.scala
diff --git a/tests/neg/tailcall/tailrec.check b/tests/neg-tailcall/tailrec.check
similarity index 100%
rename from tests/neg/tailcall/tailrec.check
rename to tests/neg-tailcall/tailrec.check
diff --git a/tests/neg/tailcall/tailrec.scala b/tests/neg-tailcall/tailrec.scala
similarity index 100%
rename from tests/neg/tailcall/tailrec.scala
rename to tests/neg-tailcall/tailrec.scala
diff --git a/tests/neg/nolib/Foo.scala b/tests/neg/nolib/Foo.scala
deleted file mode 100644
index ef4e4e70d01d..000000000000
--- a/tests/neg/nolib/Foo.scala
+++ /dev/null
@@ -1,2 +0,0 @@
-// nopos-error
-class Foo
diff --git a/tests/neg/trailingCommas/trailingCommas.scala b/tests/neg/trailingCommas.scala
similarity index 100%
rename from tests/neg/trailingCommas/trailingCommas.scala
rename to tests/neg/trailingCommas.scala
diff --git a/tests/neg/inlineAccess/C_1.scala b/tests/pending/neg/inlineAccess/C_1.scala
similarity index 100%
rename from tests/neg/inlineAccess/C_1.scala
rename to tests/pending/neg/inlineAccess/C_1.scala
diff --git a/tests/neg/inlineAccess/Test_2.scala b/tests/pending/neg/inlineAccess/Test_2.scala
similarity index 100%
rename from tests/neg/inlineAccess/Test_2.scala
rename to tests/pending/neg/inlineAccess/Test_2.scala
diff --git a/tests/pos/Foo.scala b/tests/pos/Foo.scala
new file mode 100644
index 000000000000..c389887ee5aa
--- /dev/null
+++ b/tests/pos/Foo.scala
@@ -0,0 +1 @@
+class Foo