WEB-20340 JavaScript debugger doesn't show "this" reference with ES6 fat arrows

platform/script-debugger/debugger-ui/src/MemberFilterWithNameMappings.kt

@@ -15,12 +15,8 @@
  */
 package org.jetbrains.debugger
 
-open class MemberFilterWithNameMappings(rawNameToSource: Map<String, String>?) : MemberFilter {
-  protected val rawNameToSource = rawNameToSource ?: emptyMap<String, String>()
-
-  override fun hasNameMappings(): Boolean {
-    return !rawNameToSource.isEmpty()
-  }
+open class MemberFilterWithNameMappings(protected val rawNameToSource: Map<String, String> = emptyMap()) : MemberFilter {
+  override fun hasNameMappings() = !rawNameToSource.isEmpty()
 
   override fun rawNameToSource(variable: Variable): String {
     val name = variable.name
@@ -28,9 +24,7 @@ open class MemberFilterWithNameMappings(rawNameToSource: Map<String, String>?) :
     return sourceName ?: normalizeMemberName(name)
   }
 
-  protected open fun normalizeMemberName(name: String): String {
-    return name
-  }
+  protected open fun normalizeMemberName(name: String) = name
 
   override fun sourceNameToRaw(name: String): String? {
     if (!hasNameMappings()) {

platform/script-debugger/debugger-ui/src/ScopeVariablesGroup.kt

@@ -19,8 +19,10 @@ import com.intellij.xdebugger.XDebuggerBundle
 import com.intellij.xdebugger.frame.XCompositeNode
 import com.intellij.xdebugger.frame.XValueChildrenList
 import com.intellij.xdebugger.frame.XValueGroup
+import org.jetbrains.concurrency.Promise
 import org.jetbrains.concurrency.done
 import org.jetbrains.concurrency.rejected
+import org.jetbrains.concurrency.thenAsyncAccept
 
 class ScopeVariablesGroup(val scope: Scope, parentContext: VariableContext, callFrame: CallFrame?) : XValueGroup(scope.createScopeNodeName()) {
   private val context = createVariableContext(scope, parentContext, callFrame)
@@ -42,15 +44,35 @@ class ScopeVariablesGroup(val scope: Scope, parentContext: VariableContext, call
 
     promise
       .done(node) {
-        callFrame.receiverVariable
-          .done(node) {
-            node.addChildren(if (it == null) XValueChildrenList.EMPTY else XValueChildrenList.singleton(VariableView(it, context)), true)
+        context.memberFilter
+          .thenAsyncAccept(node) { memberFilter ->
+            if (memberFilter.hasNameMappings()) {
+              memberFilter.sourceNameToRaw(RECEIVER_NAME)?.let {
+                return@thenAsyncAccept callFrame.evaluateContext.evaluate(it)
+                  .done(node) {
+                    VariableImpl(RECEIVER_NAME, it.value, null)
+                    node.addChildren(XValueChildrenList.singleton(VariableView(VariableImpl(RECEIVER_NAME, it.value, null), context)), true)
+                  }
+              }
+            }
+
+            computeReceiverVariable(callFrame, node)
           }
           .rejected(node) {
-            node.addChildren(XValueChildrenList.EMPTY, true)
+            computeReceiverVariable(callFrame, node)
           }
       }
   }
+
+  private fun computeReceiverVariable(callFrame: CallFrame, node: XCompositeNode): Promise<*> {
+    return callFrame.receiverVariable
+      .done(node) {
+        node.addChildren(if (it == null) XValueChildrenList.EMPTY else XValueChildrenList.singleton(VariableView(it, context)), true)
+      }
+      .rejected(node) {
+        node.addChildren(XValueChildrenList.EMPTY, true)
+      }
+  }
 }
 
 fun createAndAddScopeList(node: XCompositeNode, scopes: List<Scope>, context: VariableContext, callFrame: CallFrame?) {

platform/script-debugger/debugger-ui/src/com/jetbrains/javascript/debugger/NameMapper.kt

@@ -34,13 +34,13 @@ private val OPERATOR_TRIMMER = CharMatcher.INVISIBLE.or(CharMatcher.anyOf(S1))
 val NAME_TRIMMER = CharMatcher.INVISIBLE.or(CharMatcher.anyOf(S1 + ".&:"))
 
 // generateVirtualFile only for debug purposes
-open class NameMapper(private val document: Document, private val transpiledDocument: Document, private val sourceMappings: MappingList, private val sourceMap: SourceMap, private val transpiledFile: VirtualFile? = null) {
+open class NameMapper(private val document: Document, private val transpiledDocument: Document, private val sourceMappings: MappingList, protected val sourceMap: SourceMap, private val transpiledFile: VirtualFile? = null) {
   var rawNameToSource: MutableMap<String, String>? = null
     private set
 
   // PsiNamedElement, JSVariable for example
   // returns generated name
-  fun map(identifierOrNamedElement: PsiElement): String? {
+  open fun map(identifierOrNamedElement: PsiElement): String? {
     val offset = identifierOrNamedElement.textOffset
     val line = document.getLineNumber(offset)
 
@@ -67,15 +67,19 @@ open class NameMapper(private val document: Document, private val transpiledDocu
     }
 
     var sourceName = sourceEntry.name
-    if (sourceName == null || Registry.`is`("js.debugger.name.mappings.by.source.code", false)) {
+    if (sourceName == null || (Registry.`is`("js.debugger.name.mappings.by.source.code", false) || Registry.`is`("js.debugger.map.this.by.source.code", false))) {
       sourceName = (identifierOrNamedElement as? PsiNamedElement)?.name ?: identifierOrNamedElement.text ?: sourceName ?: return null
     }
 
+    addMapping(generatedName, sourceName)
+    return generatedName
+  }
+
+  fun addMapping(generatedName: String, sourceName: String) {
     if (rawNameToSource == null) {
       rawNameToSource = THashMap<String, String>()
     }
     rawNameToSource!!.put(generatedName, sourceName)
-    return generatedName
   }
 
   protected open fun extractName(rawGeneratedName: CharSequence) = NAME_TRIMMER.trimFrom(rawGeneratedName)

platform/util/resources/misc/registry.properties

@@ -554,6 +554,7 @@ js.debugger.v8.use.any.breakpoint=true
 js.debugger.chrome.use.any.breakpoint=true
 nodejs.debugger.use.jb.support=true
 js.debugger.name.mappings.by.source.code=false
+js.debugger.map.this.by.source.code=false
 js.debugger.v8.log=
 js.debugger.wip.log=
 js.debugger.fix.jspm.source.maps=false