Fix for(let x of y.prop)

src/NUglify.Tests/JavaScript/CatchVariable.cs

@@ -110,6 +110,18 @@ public void NoOuter_h()
  TestHelper.Instance.RunTest("-rename:all");
  }
 
+ [Test]
+ public void ForInLet()
+ {
+ TestHelper.Instance.RunTest();
+ }
+
+ [Test]
+ public void ForInLet_h()
+ {
+ TestHelper.Instance.RunTest("-rename:all");
+ }
+
  [Test]
  public void OuterIsGlobal()
  {

src/NUglify.Tests/NUglify.Tests.csproj

@@ -390,6 +390,12 @@
  <Content Include="TestData\JS\Expected\BlockOpts\ReturnLiteral.js">
  <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
  </Content>
+ <Content Include="TestData\JS\Expected\CatchVariable\ForInLet.js">
+ <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+ </Content>
+ <Content Include="TestData\JS\Expected\CatchVariable\ForInLet_h.js">
+ <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+ </Content>
  <Content Include="TestData\JS\Expected\ControlFlow\BreakNoLabel.js">
  <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
  </Content>
@@ -2516,6 +2522,9 @@
  <Content Include="TestData\JS\Input\BlockOpts\ReturnLiteral.js">
  <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
  </Content>
+ <Content Include="TestData\JS\Input\CatchVariable\ForInLet.js">
+ <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+ </Content>
  <Content Include="TestData\JS\Input\Classes\ClassDecl.js">
  <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
  </Content>

src/NUglify.Tests/TestData/JS/Expected/CatchVariable/ForInLet.js

@@ -0,0 +1 @@
+function go(scope){for(let test in scope.prop)console.log(test)}go({prop:[1,2,3]})

src/NUglify.Tests/TestData/JS/Expected/CatchVariable/ForInLet_h.js

@@ -0,0 +1 @@
+function go(n){for(let t in n.prop)console.log(t)}go({prop:[1,2,3]})

src/NUglify.Tests/TestData/JS/Input/CatchVariable/ForInLet.js

@@ -0,0 +1,7 @@
+function go(scope) {
+ for (let test in scope.prop) {
+ console.log(test);
+ }
+}
+
+go({ prop: [1, 2, 3] });

src/NUglify/JavaScript/CodeSettings.cs

@@ -276,11 +276,7 @@ public bool HasRenamePairs
  /// <returns>new name if it exists, null otherwise</returns>
  public string GetNewName(string sourceName)
  {
- string newName;
- if (!m_identifierReplacementMap.TryGetValue(sourceName, out newName))
- {
- newName = null;
- }
+ m_identifierReplacementMap.TryGetValue(sourceName, out var newName);
 
  return newName;
  }

src/NUglify/JavaScript/Syntax/ActivationObject.cs

@@ -16,6 +16,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Reflection;
 using NUglify.Helpers;
 using NUglify.JavaScript.Visitors;
@@ -922,6 +923,14 @@ internal virtual void AutoRenameFields()
  || !(Settings.RemoveFunctionExpressionNames && Settings.IsModificationAllowed(TreeModifications.RemoveFunctionExpressionNames))))
  {
  localField.CrunchedName = crunchEnum.NextName();
+
+ if (localField.Declarations.FirstOrDefault()?.Parent?.Parent?.Parent is ForInStatement forInStatement &&
+ forInStatement.Collection is MemberExpression memberExpression &&
+ memberExpression.Root is INameReference nameReference &&
+ localField.CrunchedName == (nameReference.VariableField.CrunchedName ?? nameReference.VariableField.Name))
+ {
+ localField.CrunchedName = crunchEnum.NextName();
+ }
  }
  }
  }

src/NUglify/JavaScript/Visitors/AnalyzeNodeVisitor.cs

@@ -249,13 +249,9 @@ private void CombineExpressions(BlockStatement node)
  {
  CombineWithPreviousExpression(node, ndx);
  }
- else
+ else if (node[ndx - 1] is VarDeclaration previousVar)
  {
- var previousVar = node[ndx - 1] as VarDeclaration;
- if (previousVar != null)
- {
- CombineWithPreviousVar(node, ndx, previousVar);
- }
+ CombineWithPreviousVar(node, ndx, previousVar);
  }
  }
  }