Migrate Babel from Flow to TypeScript (except Babel parser) (#11578)

Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

packages/babel-plugin-transform-parameters/src/params.ts

@@ -45,8 +45,8 @@ const iifeVisitor = {
 export default function convertFunctionParams(
   path,
   ignoreFunctionLength,
-  shouldTransformParam,
-  replaceRestElement,
+  shouldTransformParam?,
+  replaceRestElement?,
 ) {
   const params = path.get("params");
 

packages/babel-plugin-transform-parameters/src/rest.ts

@@ -289,7 +289,7 @@ export default function convertFunctionRest(path) {
 
   // There are only "shorthand" references
   if (!state.deopted && !state.references.length) {
-    for (const { path, cause } of (state.candidates: Array)) {
+    for (const { path, cause } of state.candidates) {
       const clonedArgsId = t.cloneNode(argsId);
       switch (cause) {
         case "indexGetter":