diff --git a/compiler/src/prog8/compiler/ModuleImporter.kt b/compiler/src/prog8/compiler/ModuleImporter.kt
index c4eaa0317..9a60e2d1f 100644
--- a/compiler/src/prog8/compiler/ModuleImporter.kt
+++ b/compiler/src/prog8/compiler/ModuleImporter.kt
@@ -51,7 +51,6 @@ class ModuleImporter(private val program: Program,
         return executeImportDirective(import, null)
     }
 
-    //private fun importModule(stream: CharStream, modulePath: Path, isLibrary: Boolean): Module {
     private fun importModule(src: SourceCode) : Module {
         val moduleAst = Prog8Parser.parseModule(src)
         program.addModule(moduleAst)
diff --git a/compilerAst/test/TestProg8Parser.kt b/compilerAst/test/TestProg8Parser.kt
index 4910fc7e6..da566e58a 100644
--- a/compilerAst/test/TestProg8Parser.kt
+++ b/compilerAst/test/TestProg8Parser.kt
@@ -4,6 +4,7 @@ import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.TestInstance
 import prog8.ast.IFunctionCall
+import prog8.ast.Module
 import prog8.ast.Node
 import prog8.ast.base.Position
 import prog8.ast.expressions.CharLiteral
@@ -17,12 +18,11 @@ import prog8.parser.SourceCode
 import prog8tests.helpers.assumeNotExists
 import prog8tests.helpers.assumeReadableFile
 import prog8tests.helpers.fixturesDir
+import kotlin.io.path.Path
+import kotlin.io.path.isRegularFile
 import kotlin.io.path.name
 import kotlin.io.path.nameWithoutExtension
-import kotlin.test.assertContains
-import kotlin.test.assertEquals
-import kotlin.test.assertFailsWith
-import kotlin.test.assertIs
+import kotlin.test.*
 
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
@@ -330,9 +330,9 @@ class TestProg8Parser {
             val mpf = module.position.file
             assertPositionOf(module, SourceCode.relative(path).toString(), 1, 0) // TODO: endCol wrong
             val mainBlock = module.statements.filterIsInstance<Block>()[0]
-            assertPositionOf(mainBlock, mpf, 1, 0)  // TODO: endCol wrong!
+            assertPositionOf(mainBlock, mpf, 2, 0)  // TODO: endCol wrong!
             val startSub = mainBlock.statements.filterIsInstance<Subroutine>()[0]
-            assertPositionOf(startSub, mpf, 2, 4)  // TODO: endCol wrong!
+            assertPositionOf(startSub, mpf, 3, 4)  // TODO: endCol wrong!
         }
 
 
@@ -378,6 +378,59 @@ class TestProg8Parser {
         }
     }
 
+    @Nested
+    inner class PositionFile {
+        @Test
+        fun `isn't absolute for filesystem paths`() {
+            val path = assumeReadableFile(fixturesDir, "simple_main.p8")
+            val module = parseModule(SourceCode.File(path))
+            assertSomethingForAllNodes(module) {
+                assertFalse(Path(it.position.file).isAbsolute)
+                assertTrue(Path(it.position.file).isRegularFile())
+            }
+        }
+
+        @Test
+        fun `is mangled string id for string sources`()
+        {
+            val srcText="""
+                %zeropage basicsafe
+                main {
+                    sub start() {
+                        ubyte aa=99
+                        aa++
+                    }
+                }
+            """.trimIndent()
+            val module = parseModule(SourceCode.Text(srcText))
+            assertSomethingForAllNodes(module) {
+                assertTrue(it.position.file.startsWith(SourceCode.stringSourcePrefix))
+            }
+        }
+
+        @Test
+        fun `is library prefixed path for resources`()
+        {
+            val resource = SourceCode.Resource("prog8lib/math.p8")
+            val module = parseModule(resource)
+            assertSomethingForAllNodes(module) {
+                assertTrue(it.position.file.startsWith(SourceCode.libraryFilePrefix))
+            }
+        }
+
+        private fun assertSomethingForAllNodes(module: Module, asserter: (Node) -> Unit) {
+            asserter(module)
+            module.statements.forEach(asserter)
+            module.statements.filterIsInstance<Block>().forEach { b ->
+                asserter(b)
+                b.statements.forEach(asserter)
+                b.statements.filterIsInstance<Subroutine>().forEach { s ->
+                    asserter(s)
+                    s.statements.forEach(asserter)
+                }
+            }
+        }    }
+
     @Nested
     inner class CharLiterals {
 
diff --git a/compilerAst/test/TestSourceCode.kt b/compilerAst/test/TestSourceCode.kt
index 04d8e5d99..5f9027814 100644
--- a/compilerAst/test/TestSourceCode.kt
+++ b/compilerAst/test/TestSourceCode.kt
@@ -1,30 +1,32 @@
 package prog8tests
 
+import org.hamcrest.MatcherAssert.assertThat
+import org.hamcrest.core.StringStartsWith
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.TestInstance
 import prog8.parser.SourceCode
 import prog8.parser.SourceCode.Companion.libraryFilePrefix
 import prog8tests.helpers.*
 import kotlin.io.path.Path
-import kotlin.test.assertContains
-import kotlin.test.assertEquals
-import kotlin.test.assertFailsWith
-import kotlin.test.assertTrue
+import kotlin.test.*
 
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
 class TestSourceCode {
 
     @Test
-    fun testFactoryMethod_Of() {
+    fun testFromString() {
         val text = """
             main { }
-        """.trimIndent()
+        """
         val src = SourceCode.Text(text)
         val actualText = src.getCharStream().toString()
 
         assertContains(src.origin, Regex("^<String@[0-9a-f]+>$"))
         assertEquals(text, actualText)
+        assertFalse(src.isFromResources)
+        assertFalse(src.isFromFilesystem)
+        assertThat(src.toString(), StringStartsWith("prog8.parser.SourceCode"))
     }
 
     @Test
@@ -54,6 +56,8 @@ class TestSourceCode {
         val expectedOrigin = SourceCode.relative(path).toString()
         assertEquals(expectedOrigin, src.origin)
         assertEquals(path.toFile().readText(), src.asString())
+        assertFalse(src.isFromResources)
+        assertTrue(src.isFromFilesystem)
     }
 
     @Test
@@ -75,6 +79,8 @@ class TestSourceCode {
 
         assertEquals("$libraryFilePrefix/$pathString", src.origin)
         assertEquals(srcFile.readText(), src.asString())
+        assertTrue(src.isFromResources)
+        assertFalse(src.isFromFilesystem)
     }
 
     @Test
diff --git a/compilerAst/test/fixtures/simple_main.p8 b/compilerAst/test/fixtures/simple_main.p8
index fb81add50..e2795ef11 100644
--- a/compilerAst/test/fixtures/simple_main.p8
+++ b/compilerAst/test/fixtures/simple_main.p8
@@ -1,4 +1,7 @@
+%zeropage basicsafe
 main {
     sub start() {
+        ubyte aa=99
+        aa++
     }
 }