fix: validate plugin object in assertNoUnwrappedItemOptionPairs

packages/babel-core/src/config/validation/options.js

@@ -27,6 +27,7 @@ import {
   type Validator,
   type OptionPath,
 } from "./option-assertions";
+import { validatePluginObject } from "./plugins";
 
 const ROOT_VALIDATORS: ValidatorSet = {
   cwd: (assertString: Validator<$PropertyType<ValidatedOptions, "cwd">>),
@@ -451,7 +452,9 @@ export function assertNoUnwrappedItemOptionPairs(
     !Array.isArray(items[1])
   ) {
     try {
-      validate(type, items[1]);
+      type === "preset"
+        ? validate(type, items[1])
+        : validatePluginObject(items[1]);
     } catch (e) {
       throw new Error(
         `.${type}[1] is not a valid ${type}. Maybe you meant to use\n` +

packages/babel-core/test/option-manager.js

@@ -43,6 +43,18 @@ describe("option-manager", () => {
       }).toThrowErrorMatchingSnapshot();
     });
 
+    it("should not throw when a preset string followed by valid preset object", () => {
+      const { plugin } = makePlugin("my-plugin");
+      expect(
+        loadOptions({
+          presets: [
+            "@babel/env",
+            { plugins: [[plugin, undefined, "my-plugin"]] },
+          ],
+        }),
+      ).toBeTruthy();
+    });
+
     it("should throw if a plugin is repeated, with information about the repeated plugin", () => {
       const { calls, plugin } = makePlugin("my-plugin");