Fix let/const selection for binding patterns

Author: andrewbranch

src/services/codefixes/convertToAsyncFunction.ts

@@ -196,8 +196,8 @@ namespace ts.codefix {
                     allVarNames.push({ identifier: synthName.identifier, symbol });
                     addNameToFrequencyMap(collidingSymbolMap, ident.text, symbol);
                 }
-                // we only care about identifiers that are parameters and declarations (don't care about other uses)
-                else if (node.parent && (isParameter(node.parent) || isVariableDeclaration(node.parent))) {
+                // we only care about identifiers that are parameters, declarations, or binding elements (don't care about other uses)
+                else if (node.parent && (isParameter(node.parent) || isVariableDeclaration(node.parent) || isBindingElement(node.parent))) {
                     const originalName = node.text;
                     const collidingSymbols = collidingSymbolMap.get(originalName);
 

tests/baselines/reference/convertToAsyncFunction/convertToAsyncFunction_arrayBindingPattern.ts

@@ -6,6 +6,6 @@ function /*[#|*/f/*|]*/(): Promise<void>{
 // ==ASYNC FUNCTION::Convert to async function==
 
 async function f(): Promise<void>{
-    let [result] = await fetch('https://typescriptlang.org');
+    const [result] = await fetch('https://typescriptlang.org');
     console.log(result);
 }

tests/baselines/reference/convertToAsyncFunction/convertToAsyncFunction_objectBindingPattern.ts

@@ -6,6 +6,6 @@ function /*[#|*/f/*|]*/(): Promise<void>{
 // ==ASYNC FUNCTION::Convert to async function==
 
 async function f(): Promise<void>{
-    let { result } = await fetch('https://typescriptlang.org');
+    const { result } = await fetch('https://typescriptlang.org');
     console.log(result);
 }