handle cases when body of for-of statement is expanded after loop conversion (#13677)

src/compiler/transformers/es2015.ts

@@ -2316,7 +2316,7 @@ namespace ts {
                 addRange(statements, convertedLoopBodyStatements);
             }
             else {
-                const statement = visitNode(node.statement, visitor, isStatement);
+                const statement = visitNode(node.statement, visitor, isStatement, /*optional*/ false, liftToBlock);
                 if (isBlock(statement)) {
                     addRange(statements, statement.statements);
                     bodyLocation = statement;

tests/baselines/reference/nestedLoopWithOnlyInnerLetCaptured.js

@@ -0,0 +1,18 @@
+//// [nestedLoopWithOnlyInnerLetCaptured.ts]
+declare let doSomething;
+
+for (let a1 of [])
+    for (let a2 of a1.someArray)
+        doSomething(() => a2);
+
+//// [nestedLoopWithOnlyInnerLetCaptured.js]
+for (var _i = 0, _a = []; _i < _a.length; _i++) {
+    var a1 = _a[_i];
+    var _loop_1 = function (a2) {
+        doSomething(function () { return a2; });
+    };
+    for (var _b = 0, _c = a1.someArray; _b < _c.length; _b++) {
+        var a2 = _c[_b];
+        _loop_1(a2);
+    }
+}

tests/baselines/reference/nestedLoopWithOnlyInnerLetCaptured.symbols

@@ -0,0 +1,15 @@
+=== tests/cases/compiler/nestedLoopWithOnlyInnerLetCaptured.ts ===
+declare let doSomething;
+>doSomething : Symbol(doSomething, Decl(nestedLoopWithOnlyInnerLetCaptured.ts, 0, 11))
+
+for (let a1 of [])
+>a1 : Symbol(a1, Decl(nestedLoopWithOnlyInnerLetCaptured.ts, 2, 8))
+
+    for (let a2 of a1.someArray)
+>a2 : Symbol(a2, Decl(nestedLoopWithOnlyInnerLetCaptured.ts, 3, 12))
+>a1 : Symbol(a1, Decl(nestedLoopWithOnlyInnerLetCaptured.ts, 2, 8))
+
+        doSomething(() => a2);
+>doSomething : Symbol(doSomething, Decl(nestedLoopWithOnlyInnerLetCaptured.ts, 0, 11))
+>a2 : Symbol(a2, Decl(nestedLoopWithOnlyInnerLetCaptured.ts, 3, 12))
+

tests/baselines/reference/nestedLoopWithOnlyInnerLetCaptured.types

@@ -0,0 +1,20 @@
+=== tests/cases/compiler/nestedLoopWithOnlyInnerLetCaptured.ts ===
+declare let doSomething;
+>doSomething : any
+
+for (let a1 of [])
+>a1 : any
+>[] : undefined[]
+
+    for (let a2 of a1.someArray)
+>a2 : any
+>a1.someArray : any
+>a1 : any
+>someArray : any
+
+        doSomething(() => a2);
+>doSomething(() => a2) : any
+>doSomething : any
+>() => a2 : () => any
+>a2 : any
+

tests/cases/compiler/nestedLoopWithOnlyInnerLetCaptured.ts

@@ -0,0 +1,6 @@
+// @target: es5
+declare let doSomething;
+
+for (let a1 of [])
+    for (let a2 of a1.someArray)
+        doSomething(() => a2);