diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/jsAstUtils.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/jsAstUtils.kt
index fb42dd62331..cacc7350a10 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/jsAstUtils.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/jsAstUtils.kt
@@ -13,10 +13,7 @@ import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.JsStatementOrigins
 import org.jetbrains.kotlin.ir.backend.js.sourceMapsInfo
 import org.jetbrains.kotlin.ir.backend.js.utils.*
-import org.jetbrains.kotlin.ir.declarations.IrClass
-import org.jetbrains.kotlin.ir.declarations.IrDeclaration
-import org.jetbrains.kotlin.ir.declarations.IrFunction
-import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
+import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
 import org.jetbrains.kotlin.ir.util.*
@@ -24,6 +21,7 @@ import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.js.backend.ast.*
 import org.jetbrains.kotlin.js.common.isValidES5Identifier
+import org.jetbrains.kotlin.js.config.SourceMapNamesPolicy
 import org.jetbrains.kotlin.js.config.SourceMapSourceEmbedding
 import org.jetbrains.kotlin.util.OperatorNameConventions
 import org.jetbrains.kotlin.utils.addIfNotNull
@@ -119,6 +117,7 @@ fun translateFunction(declaration: IrFunction, name: JsName?, context: JsGenerat
     val body = declaration.body?.accept(IrElementToJsStatementTransformer(), functionContext) as? JsBlock ?: JsBlock()
 
     val function = JsFunction(emptyScope, body, "member function ${name ?: "annon"}")
+        .withSource(declaration, context, useNameOf = declaration)
 
     function.name = name
 
@@ -522,16 +521,18 @@ object JsAstUtils {
     }
 }
 
-internal fun <T : JsNode> T.withSource(node: IrElement, context: JsGenerationContext, originalName: String? = null): T {
-    addSourceInfoIfNeed(node, context, originalName)
+internal fun <T : JsNode> T.withSource(node: IrElement, context: JsGenerationContext, useNameOf: IrDeclarationWithName? = null): T {
+    addSourceInfoIfNeed(node, context, useNameOf)
     return this
 }
 
 @Suppress("NOTHING_TO_INLINE")
-private inline fun <T : JsNode> T.addSourceInfoIfNeed(node: IrElement, context: JsGenerationContext, originalName: String?) {
+private inline fun <T : JsNode> T.addSourceInfoIfNeed(node: IrElement, context: JsGenerationContext, useNameOf: IrDeclarationWithName?) {
 
     val sourceMapsInfo = context.staticContext.backendContext.sourceMapsInfo ?: return
 
+    val originalName = useNameOf?.originalNameForUseInSourceMap(sourceMapsInfo.namesPolicy)
+
     val location = context.getLocationForIrElement(node, originalName) ?: return
 
     val isNodeFromCurrentModule = context.currentFile.module.descriptor == context.staticContext.backendContext.module
@@ -579,3 +580,22 @@ fun IrElement.getSourceInfo(fileEntry: IrFileEntry): JsLocation? {
     val startColumn = fileEntry.getColumnNumber(startOffset)
     return JsLocation(path, startLine, startColumn)
 }
+
+/**
+ * Returns a name of the original Kotlin declaration, or null, if it is a compiler generated declaration.
+ */
+private fun IrDeclarationWithName.originalNameForUseInSourceMap(policy: SourceMapNamesPolicy): String? {
+    if (policy == SourceMapNamesPolicy.NO) return null
+    when (this) {
+        is IrField -> correspondingPropertySymbol?.let {
+            return it.owner.originalNameForUseInSourceMap(policy)
+        }
+
+        is IrFunction -> if (policy == SourceMapNamesPolicy.FULLY_QUALIFIED_NAMES) {
+            fqNameWhenAvailable?.let {
+                return it.asString()
+            }
+        }
+    }
+    return name.asString()
+}
diff --git a/compiler/testData/debug/stepping/anonymousFunction.kt b/compiler/testData/debug/stepping/anonymousFunction.kt
index 162e5423391..ee25c7e5faa 100644
--- a/compiler/testData/debug/stepping/anonymousFunction.kt
+++ b/compiler/testData/debug/stepping/anonymousFunction.kt
@@ -18,5 +18,5 @@ fun box() {
 
 // EXPECTATIONS JS_IR
 // test.kt:6 box
-// test.kt:3 eval_0
-// test.kt:7 box$lambda
+// test.kt:3 eval
+// test.kt:7 box$lambda
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/callWithReceiver.kt b/compiler/testData/debug/stepping/callWithReceiver.kt
index bc7e2f01d2b..53cfc302796 100644
--- a/compiler/testData/debug/stepping/callWithReceiver.kt
+++ b/compiler/testData/debug/stepping/callWithReceiver.kt
@@ -30,5 +30,5 @@ fun box() {
 // EXPECTATIONS JS_IR
 // test.kt:9 box
 // test.kt:11 box
-// test.kt:4 protoOf.foo_26di_k$
+// test.kt:4 foo
 // test.kt:5 box
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/callableReference.kt b/compiler/testData/debug/stepping/callableReference.kt
index f98f9d2bb66..f996b9dc705 100644
--- a/compiler/testData/debug/stepping/callableReference.kt
+++ b/compiler/testData/debug/stepping/callableReference.kt
@@ -23,6 +23,7 @@ fun f(block: () -> Unit) {
 // EXPECTATIONS JS_IR
 // test.kt:3 box
 // test.kt:4 box
+// test.kt:4 box$lambda
 // test.kt:4 box
 // test.kt:10 f
-// test.kt:5
+// test.kt:5 box$lambda$lambda
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/chainCall.kt b/compiler/testData/debug/stepping/chainCall.kt
index cf06021120c..86d1f046936 100644
--- a/compiler/testData/debug/stepping/chainCall.kt
+++ b/compiler/testData/debug/stepping/chainCall.kt
@@ -32,9 +32,9 @@ fun box() {
 // EXPECTATIONS JS_IR
 // test.kt:9 box
 // test.kt:10 box
-// test.kt:4 protoOf.foo_26di_k$
+// test.kt:4 foo
 // test.kt:11 box
-// test.kt:4 protoOf.foo_26di_k$
+// test.kt:4 foo
 // test.kt:5 box
 // test.kt:13 box
-// test.kt:5 box
+// test.kt:5 box
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/class.kt b/compiler/testData/debug/stepping/class.kt
index 0a234d36b9f..5efb80a9779 100644
--- a/compiler/testData/debug/stepping/class.kt
+++ b/compiler/testData/debug/stepping/class.kt
@@ -36,5 +36,5 @@ fun box() {
 
 // EXPECTATIONS JS_IR
 // test.kt:12 box
-// test.kt:4 A
-// test.kt:14 box
+// test.kt:4 <init>
+// test.kt:14 box
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/classObject.kt b/compiler/testData/debug/stepping/classObject.kt
index bbb0295d934..78606ed1885 100644
--- a/compiler/testData/debug/stepping/classObject.kt
+++ b/compiler/testData/debug/stepping/classObject.kt
@@ -40,9 +40,9 @@ fun box() {
 
 // EXPECTATIONS JS_IR
 // test.kt:14 box
-// test.kt:5 Companion_19
-// test.kt:6 Companion_19
+// test.kt:5 <init>
+// test.kt:6 <init>
 // test.kt:15 box
 // test.kt:16 box
 // test.kt:16 box
-// test.kt:8 protoOf.foo_26di_k$
\ No newline at end of file
+// test.kt:8 foo
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/constructorCall.kt b/compiler/testData/debug/stepping/constructorCall.kt
index ccc9580ca42..265233b076e 100644
--- a/compiler/testData/debug/stepping/constructorCall.kt
+++ b/compiler/testData/debug/stepping/constructorCall.kt
@@ -34,10 +34,10 @@ fun box() {
 
 // EXPECTATIONS JS_IR
 // test.kt:6 box
-// test.kt:3 A
+// test.kt:3 <init>
 // test.kt:7 box
-// test.kt:3 A
+// test.kt:3 <init>
 // test.kt:10 box
-// test.kt:3 A
+// test.kt:3 <init>
 // test.kt:12 box
-// test.kt:3 A
+// test.kt:3 <init>
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/constructors.kt b/compiler/testData/debug/stepping/constructors.kt
index a8fc3ac02a7..336704c2639 100644
--- a/compiler/testData/debug/stepping/constructors.kt
+++ b/compiler/testData/debug/stepping/constructors.kt
@@ -188,7 +188,7 @@ class O<T>(i: T) {
 // EXPECTATIONS JS_IR
 // test.kt:4 box
 // test.kt:5 box
-// test.kt:20 C
+// test.kt:20 <init>
 // test.kt:6 box
 // test.kt:22 D_init_$Init$
 // test.kt:7 box
@@ -200,10 +200,10 @@ class O<T>(i: T) {
 // test.kt:33 G_init_$Init$
 // test.kt:34 G_init_$Init$
 // test.kt:10 box
-// test.kt:39 J
+// test.kt:39 <init>
 // test.kt:11 box
-// test.kt:42 K
-// test.kt:44 K
+// test.kt:42 <init>
+// test.kt:44 <init>
 // test.kt:12 box
 // test.kt:48 L_init_$Init$
 // test.kt:53 L
@@ -218,4 +218,4 @@ class O<T>(i: T) {
 // test.kt:66 N_init_$Init$
 // test.kt:15 box
 // test.kt:16 box
-// test.kt:73 O_init_$Init$
+// test.kt:73 O_init_$Init$
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/dataClass.kt b/compiler/testData/debug/stepping/dataClass.kt
index ebe9643f749..42270738568 100644
--- a/compiler/testData/debug/stepping/dataClass.kt
+++ b/compiler/testData/debug/stepping/dataClass.kt
@@ -62,53 +62,53 @@ fun box() {
 
 // EXPECTATIONS JS_IR
 // test.kt:13 box
-// test.kt:3 D
-// test.kt:3 D
+// test.kt:3 <init>
+// test.kt:3 <init>
 // test.kt:14 box
-// test.kt:3 D
-// test.kt:3 D
+// test.kt:3 <init>
+// test.kt:3 <init>
 // test.kt:14 box
-// test.kt:1 protoOf.equals
-// test.kt:1 protoOf.equals
-// test.kt:1 protoOf.equals
-// test.kt:1 protoOf.equals
-// test.kt:1 protoOf.equals
-// test.kt:1 protoOf.equals
+// test.kt:1 equals
+// test.kt:1 equals
+// test.kt:1 equals
+// test.kt:1 equals
+// test.kt:1 equals
+// test.kt:1 equals
 // test.kt:15 box
-// test.kt:1 protoOf.hashCode
-// test.kt:1 protoOf.hashCode
+// test.kt:1 hashCode
+// test.kt:1 hashCode
 // test.kt:16 box
-// test.kt:1 protoOf.toString
+// test.kt:1 toString
 // test.kt:17 box
 // test.kt:17 box
-// test.kt:1 protoOf.component1_7eebsc_k$
+// test.kt:1 component1
 // test.kt:17 box
-// test.kt:1 protoOf.component2_7eebsb_k$
+// test.kt:1 component2
 // test.kt:18 box
-// test.kt:1 protoOf.copy$default_roih85_k$
-// test.kt:1 protoOf.copy$default_roih85_k$
-// test.kt:1 protoOf.copy$default_roih85_k$
-// test.kt:1 protoOf.copy_t8q04r_k$
-// test.kt:3 D
-// test.kt:3 D
+// test.kt:1 copy$default
+// test.kt:1 copy$default
+// test.kt:1 copy$default
+// test.kt:1 copy
+// test.kt:3 <init>
+// test.kt:3 <init>
 // test.kt:19 box
-// test.kt:5 E
-// test.kt:5 E
+// test.kt:5 <init>
+// test.kt:5 <init>
 // test.kt:20 box
-// test.kt:5 E
-// test.kt:5 E
+// test.kt:5 <init>
+// test.kt:5 <init>
 // test.kt:20 box
-// test.kt:7 protoOf.equals
+// test.kt:7 equals
 // test.kt:21 box
-// test.kt:8 protoOf.hashCode
+// test.kt:8 hashCode
 // test.kt:22 box
-// test.kt:6 protoOf.toString
+// test.kt:6 toString
 // test.kt:23 box
 // test.kt:23 box
-// test.kt:1 protoOf.component1_7eebsc_k$
+// test.kt:1 component1
 // test.kt:23 box
-// test.kt:1 protoOf.component2_7eebsb_k$
+// test.kt:1 component2
 // test.kt:24 box
-// test.kt:9 protoOf.copy_1tks5_k$
-// test.kt:5 E
-// test.kt:5 E
+// test.kt:9 copy
+// test.kt:5 <init>
+// test.kt:5 <init>
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/defaultParameter.kt b/compiler/testData/debug/stepping/defaultParameter.kt
index ec28930b762..4db4d45c0ea 100644
--- a/compiler/testData/debug/stepping/defaultParameter.kt
+++ b/compiler/testData/debug/stepping/defaultParameter.kt
@@ -26,8 +26,8 @@ fun box() {
 // EXPECTATIONS JS_IR
 // test.kt:11 box
 // test.kt:11 box
-// test.kt:6 protoOf.foo$default_ourpn2_k$
-// test.kt:4 protoOf.computeParam_vubdyi_k$
-// test.kt:6 protoOf.foo$default_ourpn2_k$
-// test.kt:6 protoOf.foo$default_ourpn2_k$
-// test.kt:6 protoOf.foo$default_ourpn2_k$
\ No newline at end of file
+// test.kt:6 foo$default
+// test.kt:4 computeParam
+// test.kt:6 foo$default
+// test.kt:6 foo$default
+// test.kt:6 foo$default
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/enum.kt b/compiler/testData/debug/stepping/enum.kt
index b0958718d3e..13cbef7e037 100644
--- a/compiler/testData/debug/stepping/enum.kt
+++ b/compiler/testData/debug/stepping/enum.kt
@@ -54,11 +54,12 @@ fun box() {
 
 // EXPECTATIONS JS_IR
 // test.kt:22 box
-// test.kt:11 E
-// test.kt:11 E
+// test.kt:11 <init>
+// test.kt:11 <init>
 // test.kt:22 box
-// test.kt:9 protoOf.foo_26di_k$
+// test.kt:9 foo
+// test.kt:7 E$foo$lambda
 // test.kt:15 E2_initEntries
-// test.kt:14 E2
+// test.kt:14 <init>
 // test.kt:17 E2_initEntries
-// test.kt:14 E2
+// test.kt:14 <init>
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/functionCallWithLambdaParam.kt b/compiler/testData/debug/stepping/functionCallWithLambdaParam.kt
index e28048c8d5d..9f62f376a91 100644
--- a/compiler/testData/debug/stepping/functionCallWithLambdaParam.kt
+++ b/compiler/testData/debug/stepping/functionCallWithLambdaParam.kt
@@ -35,4 +35,4 @@ fun foo(f: () -> Unit) {
 // test.kt:5 box$lambda
 // test.kt:8 box
 // test.kt:14 foo
-// test.kt:9 box$lambda_0
+// test.kt:9 box$lambda
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/initBlocks.kt b/compiler/testData/debug/stepping/initBlocks.kt
index ce46d53b431..456445f43ff 100644
--- a/compiler/testData/debug/stepping/initBlocks.kt
+++ b/compiler/testData/debug/stepping/initBlocks.kt
@@ -109,18 +109,18 @@ fun box() {
 
 // EXPECTATIONS JS_IR
 // test.kt:48 box
-// test.kt:7 Foo
+// test.kt:7 <init>
 // test.kt:45 x
 // test.kt:49 box
-// test.kt:13 Bar
-// test.kt:17 Bar
+// test.kt:13 <init>
+// test.kt:17 <init>
 // test.kt:50 box
-// test.kt:23 Boo
-// test.kt:26 Boo
+// test.kt:23 <init>
+// test.kt:26 <init>
 // test.kt:45 x
-// test.kt:29 Boo
+// test.kt:29 <init>
 // test.kt:51 box
-// test.kt:34 Zoo
-// test.kt:36 Zoo
-// test.kt:39 Zoo
-// test.kt:42 Zoo
+// test.kt:34 <init>
+// test.kt:36 <init>
+// test.kt:39 <init>
+// test.kt:42 <init>
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/initBlocksCompanion.kt b/compiler/testData/debug/stepping/initBlocksCompanion.kt
index f650be90095..5779e7e6342 100644
--- a/compiler/testData/debug/stepping/initBlocksCompanion.kt
+++ b/compiler/testData/debug/stepping/initBlocksCompanion.kt
@@ -54,10 +54,10 @@ fun box() {
 
 // EXPECTATIONS JS_IR
 // test.kt:29 box
-// test.kt:8 Companion_19
-// test.kt:11 Companion_19
+// test.kt:8 <init>
+// test.kt:11 <init>
 // test.kt:26 x
-// test.kt:13 Companion_19
-// test.kt:16 Companion_19
-// test.kt:21 Companion_19
-// test.kt:30 box
+// test.kt:13 <init>
+// test.kt:16 <init>
+// test.kt:21 <init>
+// test.kt:30 box
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/kt29179.kt b/compiler/testData/debug/stepping/kt29179.kt
index 379a5b092e6..4da15be69d6 100644
--- a/compiler/testData/debug/stepping/kt29179.kt
+++ b/compiler/testData/debug/stepping/kt29179.kt
@@ -27,5 +27,5 @@ fun box() {
 
 // EXPECTATIONS JS_IR
 // test.kt:15 box
-// test.kt:5 A
-// test.kt:15 box
+// test.kt:5 <init>
+// test.kt:15 box
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/kt42208c.kt b/compiler/testData/debug/stepping/kt42208c.kt
index b0985a76e3c..9a115331a0d 100644
--- a/compiler/testData/debug/stepping/kt42208c.kt
+++ b/compiler/testData/debug/stepping/kt42208c.kt
@@ -45,4 +45,4 @@ fun baz(v:(() -> Unit)) {
 // test.kt:5 box
 // test.kt:6 box
 // test3.kt:14 baz
-// test1.kt:8 box$lambda_0
+// test1.kt:8 box$lambda
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/namedCallableReference.kt b/compiler/testData/debug/stepping/namedCallableReference.kt
index 487c30c982a..0e9bd69a44b 100644
--- a/compiler/testData/debug/stepping/namedCallableReference.kt
+++ b/compiler/testData/debug/stepping/namedCallableReference.kt
@@ -32,7 +32,8 @@ fun g() {}
 // EXPECTATIONS JS_IR
 // test.kt:3 box
 // test.kt:4 box
+// test.kt:4 g$ref
 // test.kt:4 box
 // test.kt:8 f
-// test.kt:4 l
-// test.kt:4 l
+// test.kt:4 g$ref$lambda
+// test.kt:4 g$ref$lambda
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/propertyAccessor.kt b/compiler/testData/debug/stepping/propertyAccessor.kt
index 27937b4de41..cdfab7f7aba 100644
--- a/compiler/testData/debug/stepping/propertyAccessor.kt
+++ b/compiler/testData/debug/stepping/propertyAccessor.kt
@@ -22,4 +22,4 @@ fun box() {
 // EXPECTATIONS JS_IR
 // test.kt:11 box
 // test.kt:11 box
-// test.kt:6 protoOf.get_prop_wosl9o_k$
\ No newline at end of file
+// test.kt:6 <get-prop>
\ No newline at end of file
diff --git a/compiler/testData/debug/stepping/suspendFunWithLambdaParameter.kt b/compiler/testData/debug/stepping/suspendFunWithLambdaParameter.kt
index bad906369f6..851d401dfed 100644
--- a/compiler/testData/debug/stepping/suspendFunWithLambdaParameter.kt
+++ b/compiler/testData/debug/stepping/suspendFunWithLambdaParameter.kt
@@ -19,7 +19,7 @@ suspend fun box() {
 // test.kt:11 box
 
 // EXPECTATIONS JS_IR
-// test.kt:8 protoOf.doResume_5yljmg_k$
+// test.kt:8 doResume
 // test.kt:4 foo
 // test.kt:4 foo
-// test.kt:9 box$lambda
+// test.kt:9 box$lambda
\ No newline at end of file
diff --git a/js/js.ast/src/org/jetbrains/kotlin/js/backend/JsToStringGenerationVisitor.java b/js/js.ast/src/org/jetbrains/kotlin/js/backend/JsToStringGenerationVisitor.java
index 2d5318478f0..99a4c391ab4 100644
--- a/js/js.ast/src/org/jetbrains/kotlin/js/backend/JsToStringGenerationVisitor.java
+++ b/js/js.ast/src/org/jetbrains/kotlin/js/backend/JsToStringGenerationVisitor.java
@@ -655,7 +655,6 @@ public class JsToStringGenerationVisitor extends JsVisitor {
 
     @Override
     public void visitFunction(@NotNull JsFunction x) {
-        pushSourceInfo(x.getSource());
         printCommentsBeforeNode(x);
 
         p.print(CHARS_FUNCTION);
@@ -664,7 +663,6 @@ public class JsToStringGenerationVisitor extends JsVisitor {
         printFunction(x);
 
         printCommentsAfterNode(x);
-        popSourceInfo();
     }
 
     // name(<params>) { <body> }
@@ -673,10 +671,10 @@ public class JsToStringGenerationVisitor extends JsVisitor {
             nameOf(x);
         }
 
+        pushSourceInfo(x.getSource());
         leftParen();
         boolean notFirst = false;
-        for (Object element : x.getParameters()) {
-            JsParameter param = (JsParameter) element;
+        for (JsParameter param : x.getParameters()) {
             notFirst = sepCommaOptSpace(notFirst);
             accept(param);
         }
@@ -689,6 +687,8 @@ public class JsToStringGenerationVisitor extends JsVisitor {
         printJsBlock(x.getBody(), true, x.getBody().getSource());
         sourceLocationConsumer.popSourceInfo();
 
+        popSourceInfo();
+
         needSemi = true;
     }
 
diff --git a/js/js.parser/src/com/google/gwt/dev/js/JsAstMapper.java b/js/js.parser/src/com/google/gwt/dev/js/JsAstMapper.java
index 24b13ff6263..7050badb350 100644
--- a/js/js.parser/src/com/google/gwt/dev/js/JsAstMapper.java
+++ b/js/js.parser/src/com/google/gwt/dev/js/JsAstMapper.java
@@ -1132,6 +1132,15 @@ public class JsAstMapper {
         if (astNode == null) return null;
 
         CodePosition location = node.getPosition();
+        // For functions, consider their location to be at the opening parenthesis.
+        if (node.getType() == TokenStream.FUNCTION) {
+            Node c = node.getFirstChild();
+            while (c != null && c.getType() != TokenStream.LP)
+                c = c.getNext();
+            if (c != null && c.getPosition() != null)
+                location = c.getPosition();
+        }
+
         if (location != null) {
             JsLocation jsLocation = new JsLocation(fileName, location.getLine(), location.getOffset());
             if (astNode instanceof SourceInfoAwareJsNode) {
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/handlers/JsDebugRunner.kt b/js/js.tests/test/org/jetbrains/kotlin/js/test/handlers/JsDebugRunner.kt
index 258113ab77e..929914ba39f 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/handlers/JsDebugRunner.kt
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/handlers/JsDebugRunner.kt
@@ -122,10 +122,14 @@ class JsDebugRunner(testServices: TestServices) : AbstractJsArtifactsCollector(t
         topMostCallFrame: Debugger.CallFrame,
         loggedItems: MutableList<SteppingTestLoggedData>
     ) {
-        sourceMap.getSourceLineForGeneratedLocation(topMostCallFrame.location)?.let { (sourceFile, sourceLine) ->
+        val originalFunctionName = topMostCallFrame.functionLocation?.let {
+            sourceMap.getSourceLineForGeneratedLocation(it)?.name
+        }
+        sourceMap.getSourceLineForGeneratedLocation(topMostCallFrame.location)?.let { (_, sourceFile, sourceLine, _, _) ->
+            if (sourceFile == null || sourceLine < 0) return@let
             val testFileName = testFileNameFromMappedLocation(sourceFile, sourceLine) ?: return
             val expectation =
-                formatAsSteppingTestExpectation(testFileName, sourceLine + 1, topMostCallFrame.functionName, false)
+                formatAsSteppingTestExpectation(testFileName, sourceLine + 1, originalFunctionName ?: topMostCallFrame.functionName, false)
             loggedItems.add(SteppingTestLoggedData(sourceLine + 1, false, expectation))
         }
     }
@@ -176,13 +180,11 @@ class JsDebugRunner(testServices: TestServices) : AbstractJsArtifactsCollector(t
      * Maps [location] in the generated JavaScript file to the corresponding location in a source file.
      * @return The source file path (as specified in the source map) and the line number in that source file.
      */
-    private fun SourceMap.getSourceLineForGeneratedLocation(location: Debugger.Location): Pair<String, Int>? {
-
-        fun SourceMapSegment.sourceFileAndLine() = sourceFileName!! to sourceLineNumber
+    private fun SourceMap.getSourceLineForGeneratedLocation(location: Debugger.Location): SourceMapSegment? {
 
         val group = groups.getOrNull(location.lineNumber)?.takeIf { it.segments.isNotEmpty() } ?: return null
-        val columnNumber = location.columnNumber ?: return group.segments[0].sourceFileAndLine()
-        val segment = if (columnNumber <= group.segments[0].generatedColumnNumber) {
+        val columnNumber = location.columnNumber ?: return group.segments[0]
+        return if (columnNumber <= group.segments[0].generatedColumnNumber) {
             group.segments[0]
         } else {
             val candidateIndex = group.segments.indexOfFirst {
@@ -195,7 +197,6 @@ class JsDebugRunner(testServices: TestServices) : AbstractJsArtifactsCollector(t
             else
                 group.segments[candidateIndex - 1]
         }
-        return segment?.sourceFileAndLine()
     }
 
     /**
diff --git a/js/js.translator/testData/lineNumbers/andAndWithSideEffect.kt b/js/js.translator/testData/lineNumbers/andAndWithSideEffect.kt
index b318a91a095..b2f8247520f 100644
--- a/js/js.translator/testData/lineNumbers/andAndWithSideEffect.kt
+++ b/js/js.translator/testData/lineNumbers/andAndWithSideEffect.kt
@@ -6,5 +6,5 @@ fun box(x: Int, y: Int) {
 
 fun foo(x: Int) = x
 
-// LINES(JS):    1 5 3 3 4 3 3 3 3 * 3 3 4 4 4 4 * 4 4 4 4 2 3 7 7 7
-// LINES(JS_IR):           3   3 3 * 3   * 4 4 4 * 4   4   2 *   7 7
+// LINES(JS):    1   5 3 3 4 3 3 3 3 * 3 3 4 4 4 4 * 4 4 4 4 2 3 7 7 7
+// LINES(JS_IR): 1 *         3   3 3 * 3   * 4 4 4 * 4   4   2   7 7 7
diff --git a/js/js.translator/testData/lineNumbers/backingField.kt b/js/js.translator/testData/lineNumbers/backingField.kt
index f36bacf2f50..a279e773ab0 100644
--- a/js/js.translator/testData/lineNumbers/backingField.kt
+++ b/js/js.translator/testData/lineNumbers/backingField.kt
@@ -12,5 +12,5 @@ open class A {
         }
 }
 
-// LINES(JS):    1 2 2 4 4 2 2 2   2     5 5 5 6 7 12 8 9 10    11
-// LINES(JS_IR):   2 2 4 4 * 2 2 * 2 2 *              8 9 10 10 11 * 6 6 5 6
+// LINES(JS):    1 2 2 4 4 2 2 2 2     5 5 5 6 7 12 8 9 10    11
+// LINES(JS_IR): 1 2 2 4 4 2 2 2 2 2 2         7    8 9 10 10 11 5 6 6 5 6
diff --git a/js/js.translator/testData/lineNumbers/catch.kt b/js/js.translator/testData/lineNumbers/catch.kt
index 1fc28758d6c..dce19fe0ac7 100644
--- a/js/js.translator/testData/lineNumbers/catch.kt
+++ b/js/js.translator/testData/lineNumbers/catch.kt
@@ -19,5 +19,5 @@ fun bar() {
     }
 }
 
-// LINES(JS): 1 11 3 3 5 5 6 6 8 8 9 9 2 2 * 13 20 15 15 18 18
-// LINES(JS_IR):   3 3 *   6 6 *   9 9 *           15 15 18 18
+// LINES(JS):    1 11 3 3 5 5 6 6 8 8 9 9 2 2 * 13 20 15 15 18 18
+// LINES(JS_IR): 1    3 3 *   6 6 *   9 9 *     13    15 15 18 18
diff --git a/js/js.translator/testData/lineNumbers/chainedCall.kt b/js/js.translator/testData/lineNumbers/chainedCall.kt
index c821fa142eb..33bbc126850 100644
--- a/js/js.translator/testData/lineNumbers/chainedCall.kt
+++ b/js/js.translator/testData/lineNumbers/chainedCall.kt
@@ -14,5 +14,5 @@ class C {
     val baz: dynamic get() = null
 }
 
-// LINES(JS): 1 9 2 4 3 2 6 8 7 6 11 12 12 12 14 14 14
-// LINES(JS_IR):  2 4 3 2 6 8 7 6 *  12 12 *     14 14
+// LINES(JS):    1 9 2 4 3 2 6 8 7 6 11 12 12 12 14 14 14
+// LINES(JS_IR): 1   2 4 3 2 6 8 7 6 11 12 12 12 14 14 14
diff --git a/js/js.translator/testData/lineNumbers/classCapturingLocals.kt b/js/js.translator/testData/lineNumbers/classCapturingLocals.kt
index 619205ff5b5..20d1b79e81a 100644
--- a/js/js.translator/testData/lineNumbers/classCapturingLocals.kt
+++ b/js/js.translator/testData/lineNumbers/classCapturingLocals.kt
@@ -15,4 +15,4 @@ fun A.foo() {
 fun baz() = 23
 
 // LINES(JS):    1 * 5 5 5 6 9 7 7 8 8 * 3 13 4 4 11 11 12 12 15 15 15
-// LINES(JS_IR):                              4 4 11 11 12 12 *  15 15 * 7 7 8 8
+// LINES(JS_IR): 1                       3    4 4 11 11 12 12 15 15 15 5 * 6 7 7 8 8
diff --git a/js/js.translator/testData/lineNumbers/closure.kt b/js/js.translator/testData/lineNumbers/closure.kt
index eb4efea0c8d..72d2bff1e03 100644
--- a/js/js.translator/testData/lineNumbers/closure.kt
+++ b/js/js.translator/testData/lineNumbers/closure.kt
@@ -5,5 +5,5 @@ fun box(x: Int, y: Int): Int {
     return foo(y)
 }
 
-// LINES(JS):    2 2 2 4 4 1 6 2 2 5 5
-// LINES(JS_IR):                   5 5 * 4 4
+// LINES(JS):          2 2 2 4 4 1 6 2 2 5 5
+// LINES(JS_IR): 1 5 5     2 4 4
diff --git a/js/js.translator/testData/lineNumbers/complexExpressionAsDefaultArgument.kt b/js/js.translator/testData/lineNumbers/complexExpressionAsDefaultArgument.kt
index 3f8b40f3ce5..e6eabab33d7 100644
--- a/js/js.translator/testData/lineNumbers/complexExpressionAsDefaultArgument.kt
+++ b/js/js.translator/testData/lineNumbers/complexExpressionAsDefaultArgument.kt
@@ -11,5 +11,5 @@ fun baz() = 1
 
 fun bar() = 2
 
-// LINES(JS):    1 3 3 2 2 4 3 4 4 4 5 5 2 8 8 10 10 10 12 12 12
-// LINES(JS_IR): 1 3 3 4 5 1 * 8 8 * 10 10 * 12 12
+// LINES(JS):    1     3 3 2 2 4 3 4 4 4 5 5     2 8 8 10 10 10 12 12 12
+// LINES(JS_IR): 1 * 1 3 3             4 5   1 *   8 8 10 10 10 12 12 12
diff --git a/js/js.translator/testData/lineNumbers/conditionalDecomposed.kt b/js/js.translator/testData/lineNumbers/conditionalDecomposed.kt
index 5f033bd6631..a04be13f84f 100644
--- a/js/js.translator/testData/lineNumbers/conditionalDecomposed.kt
+++ b/js/js.translator/testData/lineNumbers/conditionalDecomposed.kt
@@ -15,4 +15,4 @@ private inline fun foo(): Int {
 }
 
 // LINES(JS):    1 10 3 3 3 4 3 6   13 13 3 14        2 12 15 13 13 14 14
-// LINES(JS_IR):            4   6 * 13 13   14 14   8 2 *     13 13 14 14
+// LINES(JS_IR): 1 *        4   6 * 13 13   14 14   8 2 12    13 13 14 14
diff --git a/js/js.translator/testData/lineNumbers/coroutine.kt b/js/js.translator/testData/lineNumbers/coroutine.kt
index 8f663fd759a..51849612f55 100644
--- a/js/js.translator/testData/lineNumbers/coroutine.kt
+++ b/js/js.translator/testData/lineNumbers/coroutine.kt
@@ -15,4 +15,4 @@ suspend fun bar(): Unit {
 }
 
 // LINES(JS):    39 4 4 4 7 5 5 45 45 5 93 45 5 5 6 4 4 4 9 15 9 9 9 * 9 15 10 10 11 11 11 11 11 * 11 12 12 13 13 13 13 13 13 13 14 14 * 9 15 9 9 9 9
-// LINES(JS_IR): 19 19 * 50 50 93 93 3 45 3 45 45 6 6 19 * 9 9 9 9 9 9 9 9 * 9 9 * 10 10 * 11 * 11 12 12 * 13 * 13 13 14 14
+// LINES(JS_IR): 4 * 19 19 * 50 50 93 93 3 45 3 45 45 6 6 19 9 9 9 9 9 9 9 9 9 9 9 9 9 * 10 10 * 11 * 11 12 12 * 13 * 13 13 14 14
diff --git a/js/js.translator/testData/lineNumbers/coroutineNullAssertion.kt b/js/js.translator/testData/lineNumbers/coroutineNullAssertion.kt
index b3137943df0..3bf6f4c961f 100644
--- a/js/js.translator/testData/lineNumbers/coroutineNullAssertion.kt
+++ b/js/js.translator/testData/lineNumbers/coroutineNullAssertion.kt
@@ -9,4 +9,4 @@ suspend fun delay() {
 }
 
 // LINES(JS):    1 6 1 1 * 1 6 2 2 2 2 2 * 3 3 4 4 4 4 4 5 5 * 1 6 1 1 1 1 8 9
-// LINES(JS_IR): 1 1 1 1 1 1 1 1 * 1 1 * 2 * 3 3 3 * 5 5
+// LINES(JS_IR): 1 1 1 1 1 1 1 1 1 8 * 1 1 1 1 * 2 * 3 3 3 * 5 5
diff --git a/js/js.translator/testData/lineNumbers/dataClass.kt b/js/js.translator/testData/lineNumbers/dataClass.kt
index 11e57507183..6752c98d021 100644
--- a/js/js.translator/testData/lineNumbers/dataClass.kt
+++ b/js/js.translator/testData/lineNumbers/dataClass.kt
@@ -6,4 +6,4 @@ data class A(
 // LINES(JS):    1 2 3 * 1 2 2 1 3 3 1 1 1 2 3 1 1 1 2 3 1 1 1 2 3 1 1 1 1 1 2 3
 
 // FIXME: componentN function body should point to the corresponding property.
-// LINES(JS_IR): 2 2 3 3 * 2 2 * 3 3 * 1 1 * 1 1 * 1 1 * 1 1 1 1 * 1 1 * 1 1 1 1 1 1 * 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
+// LINES(JS_IR): 1 2 2 3 3 2 2 2 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
diff --git a/js/js.translator/testData/lineNumbers/delegateMemberVal.kt b/js/js.translator/testData/lineNumbers/delegateMemberVal.kt
index 05c78113bc0..1f27d921c8f 100644
--- a/js/js.translator/testData/lineNumbers/delegateMemberVal.kt
+++ b/js/js.translator/testData/lineNumbers/delegateMemberVal.kt
@@ -14,4 +14,4 @@ class Delegate(val f: () -> Int) {
 }
 
 // LINES(JS):    1 2 3 * 2 2 3 3 3 3 * 6 8 7 7 10 10 11 13 12 12
-// LINES(JS_IR): 3 3 * 3 3 3 * 3 3 2 1 2 * 7 7 * 10 10 * 10 10 * 12 12 * 2
+// LINES(JS_IR): 3 3 3 1 3 3 3 2 3 3 2 1 2 6 7 7 10 10 10 10 10 10 11 12 12 2 2
diff --git a/js/js.translator/testData/lineNumbers/delegatedProperty.kt b/js/js.translator/testData/lineNumbers/delegatedProperty.kt
index 65d9538ba7c..8bf8a7dea2d 100644
--- a/js/js.translator/testData/lineNumbers/delegatedProperty.kt
+++ b/js/js.translator/testData/lineNumbers/delegatedProperty.kt
@@ -15,5 +15,5 @@ class B {
     }
 }
 
-// LINES(JS):    3 4 5 * 4 4 4 * 8 9 11 10 10 13 15 14 14
-// LINES(JS_IR): 5 5 * 5 5 4 1 4 5 * 5 5 4 1 4 * 10 10 * 14 14 * 4 * 4
+// LINES(JS):    3 4 5 * 4 4 4 *                       8 9 11 10 10 13 15 14 14
+// LINES(JS_IR): 3   5 5 4     5 5 4 1 4 5 4 5 5 4 1 4 8 9    10 10 13    14 14 4 4 * 4 4
diff --git a/js/js.translator/testData/lineNumbers/delegation.kt b/js/js.translator/testData/lineNumbers/delegation.kt
index 868bd26990f..58f79db9577 100644
--- a/js/js.translator/testData/lineNumbers/delegation.kt
+++ b/js/js.translator/testData/lineNumbers/delegation.kt
@@ -19,4 +19,4 @@ val o = object : I {
 }
 
 // LINES(JS):    1 2 3 2 2 2 2 2 2 2 * 11 12 12 12 15 15 15 16 18 17 17
-// LINES(JS_IR): 11 11 * 3 3 * 1 1 * 1 1 * 1 1 * 12 12 * 17 17 * 15 15 * 11
+// LINES(JS_IR): 11 11 11 * 1 3 3 1 1 1 1 1 1 1 1 1 * 11 12 12 12 16 17 17 15 15 15 11
diff --git a/js/js.translator/testData/lineNumbers/destructuring.kt b/js/js.translator/testData/lineNumbers/destructuring.kt
index 8e35064ea92..6b4473465c5 100644
--- a/js/js.translator/testData/lineNumbers/destructuring.kt
+++ b/js/js.translator/testData/lineNumbers/destructuring.kt
@@ -28,4 +28,4 @@ fun bar(f: (Pair<String, String>) -> Unit) {
 
 
 // LINES(JS):    15 22 16 16 17 18 20 20 21 21 22 22 3 23 9 9 9 9 4 9 9 9 5 5 6 7 11 11 12 12 15 15 25 27 26 26 * 1 * 1
-// LINES(JS_IR): 1 1 * 1 1 * 9 9 9 9 9 6 6 9 7 7 9 11 11 12 12 15 15 * 26 26 * 17 17 16 18 18 16 20 20 21 21 * 1
+// LINES(JS_IR): 1 1 1 1 1 1 * 3 9 9 9 9 9 6 6 9 7 7 9 11 11 12 12 15 15 25 26 26 15 17 17 16 18 18 16 20 20 21 21 * 1
diff --git a/js/js.translator/testData/lineNumbers/destructuringInline.kt b/js/js.translator/testData/lineNumbers/destructuringInline.kt
index 93cf1e8760d..a120653187a 100644
--- a/js/js.translator/testData/lineNumbers/destructuringInline.kt
+++ b/js/js.translator/testData/lineNumbers/destructuringInline.kt
@@ -33,4 +33,4 @@ inline operator fun P.component1() = a
 inline operator fun P.component2() = b
 
 // LINES(JS):    15 22 17 17 31 18 18 33 20 20 21 21 22 22 3 23 9 9 9 9 4 9 9 9 6 6 31 7 7 33 11 11 12 12 15 15 25 27 26 26 29 29 29 * 31 31 31 33 33 33 * 1 * 1
-// LINES(JS_IR): 1 1 * 1 1 * 9 9 9 9 9 * 31 31 9 6 6 * 33 33 9 7 7 11 11 12 12 15 15 * 26 26 * 29 29 29 29 * 29 29 * 29 29 * 31 31 * 33 33 * 31 31 16 17 17 * 33 33 16 18 18 20 20 21 21 * 1
+// LINES(JS_IR): 1 1 1 1 1 1 * 3 9 9 9 9 9 * 31 31 9 6 6 * 33 33 9 7 7 11 11 12 12 15 15 25 26 26 29 29 29 29 29 29 29 29 29 29 29 31 31 31 33 33 33 15 * 31 31 16 17 17 * 33 33 16 18 18 20 20 21 21 * 1
diff --git a/js/js.translator/testData/lineNumbers/doWhileWithComplexCondition.kt b/js/js.translator/testData/lineNumbers/doWhileWithComplexCondition.kt
index 890988be6d9..d642f8e133d 100644
--- a/js/js.translator/testData/lineNumbers/doWhileWithComplexCondition.kt
+++ b/js/js.translator/testData/lineNumbers/doWhileWithComplexCondition.kt
@@ -13,5 +13,5 @@ fun box() {
     )
 }
 
-// LINES(JS):    1 14 8 8 7 3 2 2 3 3 3 8 8 11 11 * 3 7 12 3 3 4 4
-// LINES(JS_IR): 2 2 4 4 * 8 8 8 8 8 11 11 * 7 12
+// LINES(JS):    1 14 8 8 7 3 2 2     3 3 3       8 8 11 11 * 3 7 12 3 3 4 4
+// LINES(JS_IR): 1            2 2 4 4 *     8 8 8 8 8 11 11 *   7 12
diff --git a/js/js.translator/testData/lineNumbers/elvis.kt b/js/js.translator/testData/lineNumbers/elvis.kt
index 169c47818ae..2e326bab1ef 100644
--- a/js/js.translator/testData/lineNumbers/elvis.kt
+++ b/js/js.translator/testData/lineNumbers/elvis.kt
@@ -10,4 +10,4 @@ fun box(x: String?) {
 fun foo() = "bar"
 
 // LINES(JS):    3 8 7 7 4 4 4 5 5 7 7 7 7 * 5 4 5 10 10 10 * 1 * 1
-// LINES(JS_IR): 1 1 * 1 1 * 4 5 5 * 5 * 7 7 7 * 5 4 4 * 10 10 * 1
+// LINES(JS_IR): 1 1 1 1 1 1 * 3 4 5 5 * 5 * 7 7 7 * 5 4 4 10 10 10 * 1
diff --git a/js/js.translator/testData/lineNumbers/enumCompanionObject.kt b/js/js.translator/testData/lineNumbers/enumCompanionObject.kt
index 1c60eeadfc8..5210111743d 100644
--- a/js/js.translator/testData/lineNumbers/enumCompanionObject.kt
+++ b/js/js.translator/testData/lineNumbers/enumCompanionObject.kt
@@ -7,4 +7,4 @@ enum class Foo {
 }
 
 // LINES(JS):    1 1 1 1 1 1 1 1 1 2 2 4 * 2 2 2 2 4 4 5 5 * 4 4 4 4 4 4 4 * 1 1 1 * 1 1 1 1 1 1
-// LINES(JS_IR): 5 5 * 5 5
+// LINES(JS_IR): 4 * 5 5 5 5 5 * 1 * 1 * 1
diff --git a/js/js.translator/testData/lineNumbers/enumObject.kt b/js/js.translator/testData/lineNumbers/enumObject.kt
index f7f19bab519..b6fbcfe340c 100644
--- a/js/js.translator/testData/lineNumbers/enumObject.kt
+++ b/js/js.translator/testData/lineNumbers/enumObject.kt
@@ -11,4 +11,4 @@ enum class E {
 }
 
 // LINES(JS):    1 1 1 1 1 1 1 1 1 2 2 4 8 * 2 2 2 2 4 4 4 5 5 5 * 4 4 4 4 8 8 8 9 9 9 * 8 8 8 8 * 1 1 1 * 1 1 1 1 1 1 1 1 1 1
-// LINES(JS_IR): 5 5 * 9 9
+// LINES(JS_IR):                                       4 * 5 5 5 *           8 * 9 9 9 *           1 * 1 * 1
diff --git a/js/js.translator/testData/lineNumbers/expressionAsFunctionBody.kt b/js/js.translator/testData/lineNumbers/expressionAsFunctionBody.kt
index ff7508da6a4..1019a8708f8 100644
--- a/js/js.translator/testData/lineNumbers/expressionAsFunctionBody.kt
+++ b/js/js.translator/testData/lineNumbers/expressionAsFunctionBody.kt
@@ -5,4 +5,4 @@ fun foo() =
         23
 
 // LINES(JS):    1 2 2 4 5 5
-// LINES(JS_IR):   2 2 * 5 5
+// LINES(JS_IR): 1 2 2 4 5 5
diff --git a/js/js.translator/testData/lineNumbers/for.kt b/js/js.translator/testData/lineNumbers/for.kt
index bc38144d456..aa40421fe08 100644
--- a/js/js.translator/testData/lineNumbers/for.kt
+++ b/js/js.translator/testData/lineNumbers/for.kt
@@ -18,4 +18,4 @@ fun box() {
 }
 
 // LINES(JS):    1 18 2 2 10 2 2 2 2 2 2 3 3 6 6 6 6 7 7 10 10 10 10 10 10 11 11 14 14 15 15 15 15 16 16
-// LINES(JS_IR): 12 2 18 18 35 35 2 2 2 2 2 2 2 2 2 2 2 3 3 6 6 6 6 6 6 6 7 7 6 10 10 10 10 10 11 11 14 14 15 15 15 15 15 15 15 15 15 16 16 15
+// LINES(JS_IR): 1 * 12 2 18 18 35 35 2 2 2 2 2 2 2 2 2 2 2 3 3 6 6 6 6 6 6 6 7 7 6 10 10 10 10 10 11 11 14 14 15 15 15 15 15 15 15 15 15 16 16 15
diff --git a/js/js.translator/testData/lineNumbers/increment.kt b/js/js.translator/testData/lineNumbers/increment.kt
index 70710f5c143..58300b392d4 100644
--- a/js/js.translator/testData/lineNumbers/increment.kt
+++ b/js/js.translator/testData/lineNumbers/increment.kt
@@ -9,4 +9,4 @@ fun foo(x: Int) {
 }
 
 // LINES(JS):    1 9 2 2 3 3       4 4 5 5 6 6 7 7 8 8
-// LINES(JS_IR):     2 2 3 3 3 3   4 4 5 5 6 6 7 7 8 8
+// LINES(JS_IR): 1   2 2 3 3 3 3   4 4 5 5 6 6 7 7 8 8
diff --git a/js/js.translator/testData/lineNumbers/inlineArguments.kt b/js/js.translator/testData/lineNumbers/inlineArguments.kt
index 9ec83ee591c..1a2b4de7e5d 100644
--- a/js/js.translator/testData/lineNumbers/inlineArguments.kt
+++ b/js/js.translator/testData/lineNumbers/inlineArguments.kt
@@ -12,4 +12,4 @@ inline fun foo(x: Int) {
 fun bar() = 23
 
 // LINES(JS):    3 5 4 4 8 8 9 9 7 10 8 8 9 9 12 12 12 * 1 * 1
-// LINES(JS_IR): 1 1 * 1 1 * 4 4 8 8 9 9 * 8 8 9 9 * 12 12 * 1
+// LINES(JS_IR): 1 1 1 1 1 1 * 3 * 4 4 8 8 9 9 7 8 8 9 9 12 12 12 * 1
diff --git a/js/js.translator/testData/lineNumbers/inlineLocalVarsRef.kt b/js/js.translator/testData/lineNumbers/inlineLocalVarsRef.kt
index df908795859..e4b066e7f90 100644
--- a/js/js.translator/testData/lineNumbers/inlineLocalVarsRef.kt
+++ b/js/js.translator/testData/lineNumbers/inlineLocalVarsRef.kt
@@ -10,4 +10,4 @@ fun bar() {
 }
 
 // LINES(JS):    1 1 1 1 1 6 2 2 3 3 4 4 8 10 2 2 9 2 3 3 4 4
-// LINES(JS_IR):             2 2 3   4 4 *    2 2     3   4 4
+// LINES(JS_IR): 1           2 2 3   4 4 8 *  2 2     3   4 4
diff --git a/js/js.translator/testData/lineNumbers/inlineMultiModule/simple.kt b/js/js.translator/testData/lineNumbers/inlineMultiModule/simple.kt
index a1b16976574..048fff7f98b 100644
--- a/js/js.translator/testData/lineNumbers/inlineMultiModule/simple.kt
+++ b/js/js.translator/testData/lineNumbers/inlineMultiModule/simple.kt
@@ -9,7 +9,7 @@ inline fun foo(x: String) {
 }
 
 // LINES(JS):    6 6 6 6 6 9 7 7 8 8
-// LINES(JS_IR):             7 7 8 8
+// LINES(JS_IR):         6   7 7 8 8
 
 // MODULE: main(lib)
 // FILE: main.kt
@@ -23,4 +23,4 @@ fun box() {
 }
 
 // LINES(JS):    6 20 23 7 7 21 7 8 8 21 8 7 7 22 7 8 8 22 8
-// LINES(JS_IR):         7 7      8 8    *      7 7      8 8
+// LINES(JS_IR):   20 *  7 7      8 8    *      7 7      8 8
diff --git a/js/js.translator/testData/lineNumbers/inlineReturn.kt b/js/js.translator/testData/lineNumbers/inlineReturn.kt
index b944ad9657f..a4a0bce56d4 100644
--- a/js/js.translator/testData/lineNumbers/inlineReturn.kt
+++ b/js/js.translator/testData/lineNumbers/inlineReturn.kt
@@ -22,4 +22,4 @@ fun bar(x: Int) {
 }
 
 // LINES(JS):    1 1 1 1 1 1 1 1 1 17 2 2 3 3 4 7 7 9 9 10 10 11 14 14 16 16 19 22 20 20 20 20 17 2 2 3 3 4 3 7 7 9 9 10 10 11 10 14 14 16 16 20    21 21
-// LINES(JS_IR):                      2   3 3 4 7 7 9   10 10 11 14 14 16 16 *     20 20          2   3 3 4 * 7 7 9   10 10 11 *  14 14 16 16 20 20 21 21
+// LINES(JS_IR): 1                    2   3 3 4 7 7 9   10 10 11 14 14 16 16 19 *  20 20          2   3 3 4 * 7 7 9   10 10 11 *  14 14 16 16 20 20 21 21
diff --git a/js/js.translator/testData/lineNumbers/inlining.kt b/js/js.translator/testData/lineNumbers/inlining.kt
index 2d2c794959d..f303217deb9 100644
--- a/js/js.translator/testData/lineNumbers/inlining.kt
+++ b/js/js.translator/testData/lineNumbers/inlining.kt
@@ -11,5 +11,5 @@ inline fun bar() {
     println("bar2")
 }
 
-// LINES(JS):    1 7 2 2 10 10 11 11 4 4 10 10 11 11 6 6 9 9 9 9 9 12 10 10 11 11
-// LINES(JS_IR): 2 2 * 10 10 11 11 4 4 * 10 10 11 11 6 6 * 10 10 11 11
+// LINES(JS):    1 7 2 2   10 10 11 11 4 4   10 10 11 11 6 6 9 9 9 9 9 12 10 10 11 11
+// LINES(JS_IR): 1   2 2 * 10 10 11 11 4 4 * 10 10 11 11 6 6 9            10 10 11 11
diff --git a/js/js.translator/testData/lineNumbers/inliningWithLambda.kt b/js/js.translator/testData/lineNumbers/inliningWithLambda.kt
index 25d40e021ef..3e0b115fd0b 100644
--- a/js/js.translator/testData/lineNumbers/inliningWithLambda.kt
+++ b/js/js.translator/testData/lineNumbers/inliningWithLambda.kt
@@ -16,5 +16,5 @@ inline fun foo(f: () -> Unit) {
     println("after")
 }
 
-// LINES(JS):    1 11 2 2 14 14 4 4 16 16 6 6 14 14 8 8 16 16 10 10 13 13 13 13 13 17 14 14 15 15 16 16
-// LINES(JS_IR):      2 2 * 14 14 * 4 4 16 16 6 6 * 14 14 * 8 8 16 16 10 10 * 14 14 15 15 16 16
+// LINES(JS):    1 11 2 2   14 14   4 4 16 16 6 6   14 14   8 8 16 16 10 10 13 13 13 13 13 17 14 14 15 15 16 16
+// LINES(JS_IR): 1    2 2 * 14 14 * 4 4 16 16 6 6 * 14 14 * 8 8 16 16 10 10 13                14 14 15 15 16 16
diff --git a/js/js.translator/testData/lineNumbers/innerClass.kt b/js/js.translator/testData/lineNumbers/innerClass.kt
index 1c168baab6b..2e93ceddfee 100644
--- a/js/js.translator/testData/lineNumbers/innerClass.kt
+++ b/js/js.translator/testData/lineNumbers/innerClass.kt
@@ -6,5 +6,5 @@ class A(val x: Int) {
     }
 }
 
-// LINES(JS):    1 1 2 2 3 5 4 4
-// LINES(JS_IR):     2 2 *   4 4 * 1 1 * 1 1
+// LINES(JS):    1 1   2 2 3 5 4 4
+// LINES(JS_IR):     2 2 2 3   4 4 1 1 1 1 1 1
diff --git a/js/js.translator/testData/lineNumbers/isOperator.kt b/js/js.translator/testData/lineNumbers/isOperator.kt
index 98c15d8b09f..9ed10c503b0 100644
--- a/js/js.translator/testData/lineNumbers/isOperator.kt
+++ b/js/js.translator/testData/lineNumbers/isOperator.kt
@@ -11,5 +11,5 @@ inline fun foo(): Boolean {
     return true
 }
 
-// LINES(JS):    3 7             4 4 4 10 10 4 11    4     5 5 9 12 10 10 11 11 * 1 * 1
-// LINES(JS_IR):     1 1 * 1 1 * 4 *   10 10   11 11 4 4 * 5 5 *    10 10 11 11 * 1
+// LINES(JS):    3 7                   4 4 4 10 10 4 11    4     5 5 9 12 10 10 11 11 * 1 * 1
+// LINES(JS_IR):     1 1 1 1 1 1 * 3 * 4 *   10 10   11 11 4 4 * 5 5 9    10 10 11 11 * 1
diff --git a/js/js.translator/testData/lineNumbers/jsCode.kt b/js/js.translator/testData/lineNumbers/jsCode.kt
index c07a1a9418f..3ebe9b3a9f9 100644
--- a/js/js.translator/testData/lineNumbers/jsCode.kt
+++ b/js/js.translator/testData/lineNumbers/jsCode.kt
@@ -6,4 +6,4 @@ fun foo() {
 }
 
 // LINES(JS):    1 6 2 2 3 3 4 4 5 5
-// LINES(JS_IR):     2 2 3 3 4 4 5 5
+// LINES(JS_IR): 1   2 2 3 3 4 4 5 5
diff --git a/js/js.translator/testData/lineNumbers/lambdaWithClosure.kt b/js/js.translator/testData/lineNumbers/lambdaWithClosure.kt
index 6cdaaac8c17..2d5c4be6a68 100644
--- a/js/js.translator/testData/lineNumbers/lambdaWithClosure.kt
+++ b/js/js.translator/testData/lineNumbers/lambdaWithClosure.kt
@@ -5,4 +5,4 @@ fun foo(x: Int): () -> Unit = {
 fun bar() = 23
 
 // LINES(JS):    1 1 1 3 2 2 3 3 1 1 1 5 5 5
-// LINES(JS_IR):             3 3 1 *     5 5 * 2 2
+// LINES(JS_IR):     1       3 3 1     5 5 5 1 1 2 2
diff --git a/js/js.translator/testData/lineNumbers/lastExpressionInInlineLambda.kt b/js/js.translator/testData/lineNumbers/lastExpressionInInlineLambda.kt
index 3ced4fa7686..20a6021a173 100644
--- a/js/js.translator/testData/lineNumbers/lastExpressionInInlineLambda.kt
+++ b/js/js.translator/testData/lineNumbers/lastExpressionInInlineLambda.kt
@@ -24,5 +24,5 @@ fun baz() = "baz"
 
 fun boo() = "boo"
 
-// LINES(JS):    1 17 9 4 6 6 7 7 3 3 3 * 13 12 13 13 14 19 21 20 20 23 23 23 25 25 25
-// LINES(JS_IR): 4 * 7 * 3 20 20 * 12 12 12 13 14 20 20 * 20 20 * 23 23 * 25 25
+// LINES(JS):    1 17 9 4 6 6 7 7 3 3 3 *               13 12 13 13 14       19 21 20 20 23 23 23 25 25 25
+// LINES(JS_IR): 1 *    4 *   7 * 3       20 20 * 12 12    12 13    14 20 20 19    20 20 23 23 23 25 25 25
diff --git a/js/js.translator/testData/lineNumbers/literals.kt b/js/js.translator/testData/lineNumbers/literals.kt
index 33010ae7465..01acd90d623 100644
--- a/js/js.translator/testData/lineNumbers/literals.kt
+++ b/js/js.translator/testData/lineNumbers/literals.kt
@@ -27,4 +27,4 @@ fun bar(vararg x: Any?) {
 }
 
 // LINES(JS):    1 2 22 3 4 5 6 7 8 9 10 13 14 15 16 17 18 19 20 * 25 27 26 26
-// LINES(JS_IR):        3 4 5 6 7 8 9 10 13 14 15 16 17 18 19 20 *       26 26
+// LINES(JS_IR): 1 2    3 4 5 6 7 8 9 10 13 14 15 16 17 18 19 20   25    26 26
diff --git a/js/js.translator/testData/lineNumbers/longLiteral.kt b/js/js.translator/testData/lineNumbers/longLiteral.kt
index 9544cbb033e..fddfec8ef7e 100644
--- a/js/js.translator/testData/lineNumbers/longLiteral.kt
+++ b/js/js.translator/testData/lineNumbers/longLiteral.kt
@@ -6,4 +6,4 @@ fun foo() {
 }
 
 // LINES(JS):    3 * 5 1 6 2 4
-// LINES(JS_IR):           2 4
+// LINES(JS_IR):       1   2 4
diff --git a/js/js.translator/testData/lineNumbers/memberFunWithDefaultParam.kt b/js/js.translator/testData/lineNumbers/memberFunWithDefaultParam.kt
index 1f9a95c55a9..c76e2fde793 100644
--- a/js/js.translator/testData/lineNumbers/memberFunWithDefaultParam.kt
+++ b/js/js.translator/testData/lineNumbers/memberFunWithDefaultParam.kt
@@ -11,4 +11,4 @@ class B : A() {
 }
 
 // LINES(JS):    1 2 2 2 2 2 2 2 2 2 4 4 4 * 7 7 8 10 9 9
-// LINES(JS_IR): 2 2 * 2 2 2 * 4 4 * 7 * 9 9
+// LINES(JS_IR): 1 2 2 2 2 2 2 2     4 4 4   7 7 8    9 9
diff --git a/js/js.translator/testData/lineNumbers/multipleReferences.kt b/js/js.translator/testData/lineNumbers/multipleReferences.kt
index cee070c4ba9..4abfa63b33a 100644
--- a/js/js.translator/testData/lineNumbers/multipleReferences.kt
+++ b/js/js.translator/testData/lineNumbers/multipleReferences.kt
@@ -12,5 +12,5 @@ object O {
     val y = 23
 }
 
-// LINES(JS):    1 9 2 2 3 3 4 4 6 6 7 7 8 8 11 11 12 12 *       11 11 11 11 11 11
-// LINES(JS_IR):     2 2 3 3 4 4 6 6 7 7 8 8 *     12 12 * 12 12
+// LINES(JS):    1 9 2 2 3 3 4 4 6 6 7 7 8 8 11 11   12 12          * 11 11 11 11 11 11
+// LINES(JS_IR): 1   2 2 3 3 4 4 6 6 7 7 8 8 11    * 12 12 12 12 12
diff --git a/js/js.translator/testData/lineNumbers/objectInstanceFunction.kt b/js/js.translator/testData/lineNumbers/objectInstanceFunction.kt
index bbddea06a31..850cfbeabd8 100644
--- a/js/js.translator/testData/lineNumbers/objectInstanceFunction.kt
+++ b/js/js.translator/testData/lineNumbers/objectInstanceFunction.kt
@@ -5,4 +5,4 @@ fun foo() {
 }
 
 // LINES(JS):    1 1 * 1 1 1 1 1 1 3 5 4 4
-// LINES(JS_IR):                       4 4
+// LINES(JS_IR): 1   *             3   4 4
diff --git a/js/js.translator/testData/lineNumbers/optionalArgs.kt b/js/js.translator/testData/lineNumbers/optionalArgs.kt
index 2401964d7b5..2c8348a4f8d 100644
--- a/js/js.translator/testData/lineNumbers/optionalArgs.kt
+++ b/js/js.translator/testData/lineNumbers/optionalArgs.kt
@@ -7,5 +7,5 @@ fun box(
     println(y)
 }
 
-// LINES(JS):    1 8 2 2 2 2 3 3 3 4 6 6 7 7
-// LINES(JS_IR): 1 2 1 1 4 1 6 6 7 7
+// LINES(JS):    1 8 2 2 2 2     3 3 3 4   6 6 7 7
+// LINES(JS_IR): 1 1 2       1 1       4 1 6 6 7 7
diff --git a/js/js.translator/testData/lineNumbers/propertyWithoutInitializer.kt b/js/js.translator/testData/lineNumbers/propertyWithoutInitializer.kt
index 411e86b20e5..5d967dd0a0b 100644
--- a/js/js.translator/testData/lineNumbers/propertyWithoutInitializer.kt
+++ b/js/js.translator/testData/lineNumbers/propertyWithoutInitializer.kt
@@ -10,4 +10,4 @@ open class A {
 }
 
 // LINES(JS):    1 2 4 7 7 8 8       4 4 4
-// LINES(JS_IR):       7 7 8 8 * 2 2 * 4 4
+// LINES(JS_IR): 1     7 7 8 8 2 2 2 4 4 4
diff --git a/js/js.translator/testData/lineNumbers/simple.kt b/js/js.translator/testData/lineNumbers/simple.kt
index 59ef6292cad..64f870d8f50 100644
--- a/js/js.translator/testData/lineNumbers/simple.kt
+++ b/js/js.translator/testData/lineNumbers/simple.kt
@@ -4,4 +4,4 @@ fun box() {
 }
 
 // LINES(JS):    1 4 2 2 3 3
-// LINES(JS_IR):     2 2 3 3
+// LINES(JS_IR): 1   2 2 3 3
diff --git a/js/js.translator/testData/lineNumbers/stringLiteral.kt b/js/js.translator/testData/lineNumbers/stringLiteral.kt
index 3ece5b624de..52376927cb3 100644
--- a/js/js.translator/testData/lineNumbers/stringLiteral.kt
+++ b/js/js.translator/testData/lineNumbers/stringLiteral.kt
@@ -5,4 +5,4 @@ fun box(x: Int): String {
 }
 
 // LINES(JS):    1 5 2 2 3 4
-// LINES(JS_IR):     2 2 3 4
+// LINES(JS_IR): 1   2 2 3 4
diff --git a/js/js.translator/testData/lineNumbers/syntheticCodeInConstructors.kt b/js/js.translator/testData/lineNumbers/syntheticCodeInConstructors.kt
index 94b8bca26ff..1bc13654118 100644
--- a/js/js.translator/testData/lineNumbers/syntheticCodeInConstructors.kt
+++ b/js/js.translator/testData/lineNumbers/syntheticCodeInConstructors.kt
@@ -26,4 +26,4 @@ class C : A {
 }
 
 // LINES(JS):    1 1 3 * 1 1 1 1 1 1 7 * 9 10 11 * 15 15 16 17 14    19 15 15 22 22 23 24 22 22
-// LINES(JS_IR):     3 *                   10 11 *       16 17    15 19 *           23 24       23
+// LINES(JS_IR): 1 * 3 *             7   9 10 11         16 17    15 19 *           23 24       23
diff --git a/js/js.translator/testData/lineNumbers/syntheticCodeInEnums.kt b/js/js.translator/testData/lineNumbers/syntheticCodeInEnums.kt
index f5356f56d45..46afba8f84b 100644
--- a/js/js.translator/testData/lineNumbers/syntheticCodeInEnums.kt
+++ b/js/js.translator/testData/lineNumbers/syntheticCodeInEnums.kt
@@ -8,5 +8,5 @@ enum class E {
     }
 }
 
-// LINES(JS):    1 1 1 1 1 1 1 1 1 2 2 3 3 4 * 2 2 2 2 * 3 3 3 3 4 4 4 6 6 * 4 4 4 4 * 1 1 1 * 1 1 1 1 1 1 1 1 1 1
-// LINES(JS_IR): 6 6
+// LINES(JS):    1 1 1 1 1 1 1 1 1 2 2 3 3 4 * 2 2 2 2 * 3 3 3 3 4 4 4   6 6 * 4 4 4 4 * 1   1 1 * 1 1 1 1 1 1 1 1 1 1
+// LINES(JS_IR):                                                   4   * 6 6 *           1 *   1 * 1
diff --git a/js/js.translator/testData/lineNumbers/valParameter.kt b/js/js.translator/testData/lineNumbers/valParameter.kt
index e10502c6c72..b5d359c04ee 100644
--- a/js/js.translator/testData/lineNumbers/valParameter.kt
+++ b/js/js.translator/testData/lineNumbers/valParameter.kt
@@ -7,5 +7,5 @@ fun foo() {
     A(23, "foo")
 }
 
-// LINES(JS):    1 2 3 * 6 8 7 7
-// LINES(JS_IR): 2 2 3 3 * 2 2 * 3 3 * 7 7
+// LINES(JS):    1 2   3 *             6 8 7 7
+// LINES(JS_IR): 1 2 2 3 3 2 2 2 3 3 3 6   7 7
diff --git a/js/js.translator/testData/lineNumbers/whenEntryWithMultipleConditions.kt b/js/js.translator/testData/lineNumbers/whenEntryWithMultipleConditions.kt
index 919ab11f3f3..d2d47307cda 100644
--- a/js/js.translator/testData/lineNumbers/whenEntryWithMultipleConditions.kt
+++ b/js/js.translator/testData/lineNumbers/whenEntryWithMultipleConditions.kt
@@ -19,4 +19,4 @@ fun box(x: Int) {
 }
 
 // LINES(JS):    1 19 4 4 3 3 4 6 9 9 6 11 13 13 11 16 16 3 2
-// LINES(JS_IR): 4 4 2 6 7 8 9 11 12 13 16
+// LINES(JS_IR): 1 4 4 2 6 7 8 9 11 12 13 16
diff --git a/js/js.translator/testData/lineNumbers/whenEntryWithMultipleConditionsNonOptimized.kt b/js/js.translator/testData/lineNumbers/whenEntryWithMultipleConditionsNonOptimized.kt
index 5e21b38637b..fd83f6bd0d5 100644
--- a/js/js.translator/testData/lineNumbers/whenEntryWithMultipleConditionsNonOptimized.kt
+++ b/js/js.translator/testData/lineNumbers/whenEntryWithMultipleConditionsNonOptimized.kt
@@ -29,4 +29,4 @@ fun four() = 4
 fun five() = 5
 
 // LINES(JS):    1 19 4 4 3 6 4 6 4 7 4 8 9 9 11 4 11 4 12 13 13 16 16 2 21 21 21 23 23 23 25 25 25 27 27 27 29 29 29
-// LINES(JS_IR): 4 4 2 6 7 8 9 11 12 13 16 * 21 21 * 23 23 * 25 25 * 27 27 * 29 29
+// LINES(JS_IR): 1 4 4 2 6 7 8 9 11 12 13 16 21 21 21 23 23 23 25 25 25 27 27 27 29 29 29
diff --git a/js/js.translator/testData/lineNumbers/whenIn.kt b/js/js.translator/testData/lineNumbers/whenIn.kt
index a96f0a37f81..b263e646f10 100644
--- a/js/js.translator/testData/lineNumbers/whenIn.kt
+++ b/js/js.translator/testData/lineNumbers/whenIn.kt
@@ -14,4 +14,4 @@ fun foo(): Int = 23
 fun bar(): IntRange = 1000..2000
 
 // LINES(JS):    1 10 2 2 2 2 3 3 4 4 5 5 6 6 7 7       8 8 12 12 12 14 14 14
-// LINES(JS_IR):          2 2 3   4 4 5   6 6 7 7 7 7 7 8 8 *  12 12 *  14 14
+// LINES(JS_IR): 1        2 2 3   4 4 5   6 6 7 7 7 7 7 8 8 12 12 12 14 14 14
diff --git a/js/js.translator/testData/lineNumbers/whenIs.kt b/js/js.translator/testData/lineNumbers/whenIs.kt
index 540a0d82b4d..0fda1c71920 100644
--- a/js/js.translator/testData/lineNumbers/whenIs.kt
+++ b/js/js.translator/testData/lineNumbers/whenIs.kt
@@ -14,4 +14,4 @@ open class A
 open class B : A()
 
 // LINES(JS):    1 10 2 2 2 2 3 3 4 4 5 5 6 6 8 8 12 * 14 14
-// LINES(JS_IR):          2 2 3   4 4 5   6 6 8 8 *    14
+// LINES(JS_IR): 1        2 2 3   4 4 5   6 6 8 8 12   14 14
diff --git a/js/js.translator/testData/lineNumbers/whileWithComplexCondition.kt b/js/js.translator/testData/lineNumbers/whileWithComplexCondition.kt
index e18e8a354b1..e63f3d3b9fd 100644
--- a/js/js.translator/testData/lineNumbers/whileWithComplexCondition.kt
+++ b/js/js.translator/testData/lineNumbers/whileWithComplexCondition.kt
@@ -13,4 +13,4 @@ fun box() {
 }
 
 // LINES(JS):    1 13 5 5 4 2 2 3 5 5       8 8 * 3 4 9 3 11 11
-// LINES(JS_IR):            2 2 * 5 5 5 5 5 8 8 *   4 9 * 11 11
+// LINES(JS_IR): 1          2 2 * 5 5 5 5 5 8 8 *   4 9 * 11 11