fix: eslint 9.27.0 support

Author: BenoitZugmeyer

src/verifyWithFlatConfigPatch.js

@@ -79,13 +79,12 @@ function createVerifyWithFlatConfigPatch(eslintModule, verifyWithFlatConfig) {
  const localMessages = verifyWithFlatConfig.call(
  this,
  sourceCodes.get(codePart) || String(codePart),
- {
- ...providedConfig,
- rules: Object.assign(
- { [`${PREPARE_PLUGIN_NAME}/${PREPARE_RULE_NAME}`]: "error" },
- !ignoreRules && providedConfig.rules
- ),
- },
+ createNewConfig(providedConfig, {
+ rules: {
+ [`${PREPARE_PLUGIN_NAME}/${PREPARE_RULE_NAME}`]: "error",
+ ...(!ignoreRules && providedConfig.rules),
+ },
+ }),
  ignoreRules
  ? {
  ...providedOptions,
@@ -160,13 +159,20 @@ function verifyExternalHtmlPlugin(eslintModule, config, callOriginalVerify) {
 
  return [
  callOriginalVerify(),
- {
- ...config,
+ createNewConfig(config, {
  languageOptions: {
  ...config.languageOptions,
  parser: eslintModule.require("espree"),
  },
  rules,
- },
+ }),
  ]
 }
+
+/**
+ * Creates a clone of the provided config object so it can be modified without affecting the
+ * original.
+ */
+function createNewConfig(originalConfig, overrides) {
+ return Object.setPrototypeOf(overrides, originalConfig)
+}