Delete undefined options so we handle old core versions with new CLI versions. (#8728)

packages/babel-cli/src/babel/options.js

@@ -221,8 +221,7 @@ export default function parseArgv(args: Array<string>) {
 
   const opts = commander.opts();
 
-  return {
+  const babelOptions = {
-    babelOptions: {
     presets: opts.presets,
     plugins: opts.plugins,
     rootMode: opts.rootMode,
@@ -247,10 +246,22 @@ export default function parseArgv(args: Array<string>) {
     // leave them undefined so that @babel/core can handle the
     // default-assignment logic on its own.
     babelrc: opts.babelrc === true ? undefined : opts.babelrc,
-      highlightCode:
+    highlightCode: opts.highlightCode === true ? undefined : opts.highlightCode,
-        opts.highlightCode === true ? undefined : opts.highlightCode,
     comments: opts.comments === true ? undefined : opts.comments,
-    },
+  };
+
+  // If the @babel/cli version is newer than the @babel/core version, and we have added
+  // new options for @babel/core, we'll potentially get option validation errors from
+  // @babel/core. To avoid that, we delete undefined options, so @babel/core will only
+  // give the error if users actually pass an unsupported CLI option.
+  for (const key of Object.keys(babelOptions)) {
+    if (babelOptions[key] === undefined) {
+      delete babelOptions[key];
+    }
+  }
+
+  return {
+    babelOptions,
     cliOptions: {
       filename: opts.filename,
       filenames,