diff --git a/compilerAst/test/TestAstToSourceCode.kt b/compilerAst/test/TestAstToSourceCode.kt
new file mode 100644
index 000000000..8aaa8cd19
--- /dev/null
+++ b/compilerAst/test/TestAstToSourceCode.kt
@@ -0,0 +1,139 @@
+package prog8tests
+
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.TestInstance
+import org.junit.jupiter.api.assertThrows
+import kotlin.test.*
+
+import prog8.ast.*
+import prog8.ast.base.DataType
+import prog8.ast.base.Position
+import prog8.ast.expressions.Expression
+import prog8.ast.expressions.InferredTypes
+import prog8.ast.expressions.NumericLiteralValue
+import prog8.parser.Prog8Parser.parseModule
+import prog8.parser.SourceCode
+
+import prog8.ast.AstToSourceCode
+import prog8.parser.ParseError
+
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class TestAstToSourceCode {
+
+    object DummyFunctions: IBuiltinFunctions {
+        override val names: Set<String> = emptySet()
+        override val purefunctionNames: Set<String> = emptySet()
+        override fun constValue(name: String, args: List<Expression>, position: Position, memsizer: IMemSizer): NumericLiteralValue? = null
+        override fun returnType(name: String, args: MutableList<Expression>) = InferredTypes.InferredType.unknown()
+    }
+
+    object DummyMemsizer: IMemSizer {
+        override fun memorySize(dt: DataType): Int = 0
+    }
+
+    fun generateP8(module: Module) : String {
+        val program = Program("test", mutableListOf(module), DummyFunctions, DummyMemsizer)
+        module.linkParents(program)
+        module.program = program
+
+        var generatedText = ""
+        val it = AstToSourceCode({ str -> generatedText += str }, program)
+        it.visit(program)
+
+        return generatedText
+    }
+
+    fun roundTrip(module: Module): Pair<String, Module> {
+        val generatedText = generateP8(module)
+        try {
+            val parsedAgain = parseModule(SourceCode.of(generatedText))
+            return Pair(generatedText, parsedAgain)
+        } catch (e: ParseError) {
+            assert(false, { "should produce valid Prog8 but threw $e" })
+            throw e
+        }
+    }
+
+    @Test
+    fun testMentionsInternedStringsModule() {
+        val orig = SourceCode.of("\n")
+        val (txt, module) = roundTrip(parseModule(orig))
+        // assertContains has *actual* first!
+        assertContains(txt, Regex(";.*$internedStringsModuleName"))
+    }
+
+    @Test
+    fun testTargetDirectiveAndComment() {
+        val orig = SourceCode.of("%target 42  ; invalid arg - shouldn't matter\n")
+        val (txt, module) = roundTrip(parseModule(orig))
+        // assertContains has *actual* first!
+        assertContains(txt, Regex("%target +42"))
+    }
+
+    @Test
+    fun testImportDirectiveWithLib() {
+        val orig = SourceCode.of("%import textio\n")
+        val (txt, module) = roundTrip(parseModule(orig))
+        // assertContains has *actual* first!
+        assertContains(txt, Regex("%import +textio"))
+    }
+
+    @Test
+    fun testImportDirectiveWithUserModule() {
+        val orig = SourceCode.of("%import my_own_stuff\n")
+        val (txt, module) = roundTrip(parseModule(orig))
+        // assertContains has *actual* first!
+        assertContains(txt, Regex("%import +my_own_stuff"))
+    }
+
+
+    @Test
+    fun testStringLiteral_noAlt() {
+        val orig = SourceCode.of("""
+            main {
+                str s = "fooBar\n"
+            }
+        """)
+        val (txt, module) = roundTrip(parseModule(orig))
+        // assertContains has *actual* first!
+        assertContains(txt, Regex("str +s += +\"fooBar\\\\n\""))
+    }
+
+    @Test
+    fun testStringLiteral_withAlt() {
+        val orig = SourceCode.of("""
+            main {
+                str sAlt = @"fooBar\n"
+            }
+        """)
+        val (txt, module) = roundTrip(parseModule(orig))
+        // assertContains has *actual* first!
+        assertContains(txt, Regex("str +sAlt += +@\"fooBar\\\\n\""))
+    }
+
+    @Test
+    fun testCharLiteral_noAlt() {
+        val orig = SourceCode.of("""
+            main {
+                ubyte c = 'x'
+            }
+        """)
+        val (txt, module) = roundTrip(parseModule(orig))
+        // assertContains has *actual* first!
+        assertContains(txt, Regex("ubyte +c += +'x'"), "char literal")
+    }
+
+    @Test
+    fun testCharLiteral_withAlt() {
+        val orig = SourceCode.of("""
+            main {
+                ubyte cAlt = @'x'
+            }
+        """)
+        val (txt, module) = roundTrip(parseModule(orig))
+        // assertContains has *actual* first!
+        assertContains(txt, Regex("ubyte +cAlt += +@'x'"), "alt char literal")
+    }
+
+}
diff --git a/compilerAst/test/TestProg8Parser.kt b/compilerAst/test/TestProg8Parser.kt
index 202464f5c..cb80c5030 100644
--- a/compilerAst/test/TestProg8Parser.kt
+++ b/compilerAst/test/TestProg8Parser.kt
@@ -1,15 +1,16 @@
 package prog8tests
 
 import org.junit.jupiter.api.Test
-import prog8.ast.Node
-import prog8.ast.base.Position
-import prog8.ast.statements.*
 import kotlin.test.*
 import java.nio.file.Path   // TODO: use kotlin.io.path.Path instead
 import kotlin.io.path.*
+
 import prog8.parser.ParseError
 import prog8.parser.Prog8Parser.parseModule
 import prog8.parser.SourceCode
+import prog8.ast.Node
+import prog8.ast.base.Position
+import prog8.ast.statements.*
 
 
 class TestProg8Parser {