diff --git a/compiler/test/TestCompilerOnCharLit.kt b/compiler/test/TestCompilerOnCharLit.kt
index 3c6fcb600..43344200e 100644
--- a/compiler/test/TestCompilerOnCharLit.kt
+++ b/compiler/test/TestCompilerOnCharLit.kt
@@ -2,6 +2,9 @@ package prog8tests
 
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.TestInstance
+import kotlin.io.path.*
+import kotlin.test.*
+
 import prog8.ast.IFunctionCall
 import prog8.ast.base.DataType
 import prog8.ast.base.VarDeclType
@@ -9,12 +12,6 @@ import prog8.ast.expressions.IdentifierReference
 import prog8.ast.expressions.NumericLiteralValue
 import prog8.compiler.compileProgram
 import prog8.compiler.target.Cx16Target
-import kotlin.io.path.Path
-import kotlin.io.path.absolute
-import kotlin.io.path.isDirectory
-import kotlin.test.assertEquals
-import kotlin.test.assertIs
-import kotlin.test.assertTrue
 
 
 /**
@@ -29,7 +26,7 @@ class TestCompilerOnCharLit {
     val outputDir = workingDir.resolve("build/tmp/test")
 
     @Test
-    fun testDirectoriesSanityCheck() {
+    fun sanityCheckDirectories() {
         assertEquals("compiler", workingDir.fileName.toString())
         assertTrue(fixturesDir.isDirectory(), "sanity check; should be directory: $fixturesDir")
         assertTrue(outputDir.isDirectory(), "sanity check; should be directory: $outputDir")
diff --git a/compilerAst/test/TestSourceCode.kt b/compilerAst/test/TestSourceCode.kt
index 7a20767f2..22e54cc12 100644
--- a/compilerAst/test/TestSourceCode.kt
+++ b/compilerAst/test/TestSourceCode.kt
@@ -2,8 +2,8 @@ package prog8tests
 
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.TestInstance
+import org.junit.jupiter.api.assertThrows
 import kotlin.test.*
-import java.nio.file.Path   // TODO: use kotlin.io.path.Path instead
 import kotlin.io.path.*
 
 import prog8.parser.SourceCode
@@ -11,6 +11,19 @@ import prog8.parser.SourceCode
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
 class TestSourceCode {
+    val workingDir = Path("").absolute()    // Note: Path(".") does NOT work..!
+    val fixturesDir = workingDir.resolve("test/fixtures")
+    val resourcesDir = workingDir.resolve("res")
+    val outputDir = workingDir.resolve("build/tmp/test")
+
+    @Test
+    fun sanityCheckDirectories() {
+        assertEquals("compilerAst", workingDir.fileName.toString())
+        assertTrue(workingDir.isDirectory(), "sanity check; should be directory: $workingDir")
+        assertTrue(fixturesDir.isDirectory(), "sanity check; should be directory: $fixturesDir")
+        assertTrue(resourcesDir.isDirectory(), "sanity check; should be directory: $resourcesDir")
+        assertTrue(outputDir.isDirectory(), "sanity check; should be directory: $outputDir")
+    }
 
     @Test
     fun testFactoryMethod_Of() {
@@ -27,7 +40,7 @@ class TestSourceCode {
     @Test
     fun testFromPathWithNonExistingPath() {
         val filename = "i_do_not_exist.p8"
-        val path = Path.of("test", "fixtures", filename)
+        val path = fixturesDir.resolve(filename)
 
         assertFalse(path.exists(), "sanity check: file should not exist: ${path.absolute()}")
         assertFailsWith<NoSuchFileException> { SourceCode.fromPath(path) }
@@ -35,8 +48,8 @@ class TestSourceCode {
 
     @Test
     fun testFromPathWithMissingExtension_p8() {
-        val pathWithoutExt = Path.of("test", "fixtures", "simple_main")
-        val pathWithExt = Path.of(pathWithoutExt.toString() + ".p8")
+        val pathWithoutExt = fixturesDir.resolve("simple_main")
+        val pathWithExt = Path(pathWithoutExt.toString() + ".p8")
 
         assertTrue(pathWithExt.isRegularFile(), "sanity check: should be normal file: ${pathWithExt.absolute()}")
         assertTrue(pathWithExt.isReadable(), "sanity check: should be readable: ${pathWithExt.absolute()}")
@@ -45,16 +58,13 @@ class TestSourceCode {
 
     @Test
     fun testFromPathWithDirectory() {
-        val path = Path.of("test", "fixtures")
-
-        assertTrue(path.isDirectory(), "sanity check: should be a directory")
-        assertFailsWith<AccessDeniedException> { SourceCode.fromPath(path) }
+        assertFailsWith<AccessDeniedException> { SourceCode.fromPath(fixturesDir) }
     }
 
     @Test
     fun testFromPathWithExistingPath() {
         val filename = "simple_main.p8"
-        val path = Path.of("test", "fixtures", filename)
+        val path = fixturesDir.resolve(filename)
         val src = SourceCode.fromPath(path)
 
         val expectedOrigin = path.normalize().absolutePathString()
@@ -68,7 +78,7 @@ class TestSourceCode {
     @Test
     fun testFromPathWithExistingNonNormalizedPath() {
         val filename = "simple_main.p8"
-        val path = Path.of(".", "test", "..", "test", "fixtures", filename)
+        val path = Path(".", "test", "..", "test", "fixtures", filename)
         val src = SourceCode.fromPath(path)
 
         val expectedOrigin = path.normalize().absolutePathString()
@@ -79,4 +89,92 @@ class TestSourceCode {
         assertEquals(expectedSrcText, actualSrcText)
     }
 
+    @Test
+    fun testFromResourcesWithExistingP8File_withoutLeadingSlash() {
+        val pathString = "prog8lib/math.p8"
+        val src = SourceCode.fromResources(pathString)
+
+        assertEquals("@embedded@/$pathString", src.origin)
+
+        val expectedSrcText = resourcesDir.resolve(pathString).toFile().readText()
+        val actualSrcText = src.asString()
+        assertEquals(expectedSrcText, actualSrcText)
+    }
+
+    @Test
+    fun testFromResourcesWithExistingP8File_withLeadingSlash() {
+        val pathString = "/prog8lib/math.p8"
+        val src = SourceCode.fromResources(pathString)
+
+        assertEquals("@embedded@$pathString", src.origin)
+
+        val expectedSrcText = resourcesDir.resolve(pathString.substringAfter("/")).toFile().readText()
+        val actualSrcText = src.asString()
+        assertEquals(expectedSrcText, actualSrcText)
+    }
+
+    @Test
+    fun testFromResourcesWithExistingAsmFile_withoutLeadingSlash() {
+        val pathString = "prog8lib/math.asm"
+        val src = SourceCode.fromResources(pathString)
+
+        assertEquals("@embedded@/$pathString", src.origin)
+
+        val expectedSrcText = resourcesDir.resolve(pathString).toFile().readText()
+        val actualSrcText = src.asString()
+        assertEquals(expectedSrcText, actualSrcText)
+        assertTrue(src.isFromResources, ".isFromResources")
+    }
+
+    @Test
+    fun testFromResourcesWithExistingAsmFile_withLeadingSlash() {
+        val pathString = "/prog8lib/math.asm"
+        val src = SourceCode.fromResources(pathString)
+
+        assertEquals("@embedded@$pathString", src.origin)
+
+        val expectedSrcText = resourcesDir.resolve(pathString.substringAfter("/")).toFile().readText()
+        val actualSrcText = src.asString()
+        assertEquals(expectedSrcText, actualSrcText)
+    }
+
+    @Test
+    fun testFromResourcesWithNonNormalizedPath() {
+        val pathString = "/prog8lib/../prog8lib/math.p8"
+        val src = SourceCode.fromResources(pathString)
+
+        assertEquals("@embedded@/prog8lib/math.p8", src.origin)
+
+        val expectedSrcText = Path( "res", pathString).toFile().readText()
+        val actualSrcText = src.asString()
+        assertEquals(expectedSrcText, actualSrcText)
+        assertTrue(src.isFromResources, ".isFromResources")
+    }
+
+
+    @Test
+    fun testFromResourcesWithNonExistingFile_withLeadingSlash() {
+        val pathString = "/prog8lib/i_do_not_exist"
+        val resPath = resourcesDir.resolve(pathString.substringAfter("/"))
+        assertFalse(resPath.exists(), "sanity check: should not exist: $resPath")
+        assertThrows<NoSuchFileException> { SourceCode.fromResources(pathString) }
+    }
+    @Test
+    fun testFromResourcesWithNonExistingFile_withoutLeadingSlash() {
+        val pathString = "prog8lib/i_do_not_exist"
+        val resPath = resourcesDir.resolve(pathString)
+        assertFalse(resPath.exists(), "sanity check: should not exist: $resPath")
+        assertThrows<NoSuchFileException> { SourceCode.fromResources(pathString) }
+    }
+
+    /**
+     * TODO("inside resources: cannot tell apart a folder from a file")
+     */
+    //@Test
+    fun testFromResourcesWithDirectory() {
+        val pathString = "/prog8lib"
+        assertThrows<AccessDeniedException> { SourceCode.fromResources(pathString) }
+    }
+
+
 }