use the node --import option as suggested

replacing --loader ts-node/esm/transpile-only, which gives the following warning:

(node:33248) ExperimentalWarning: `--experimental-loader` may be removed in the future; instead use `register()`:
--import 'data:text/javascript,import { register } from "node:module"; import { pathToFileURL } from "node:url"; register("ts-node/esm/transpile-only", pathToFileURL("./"));'

.eslintrc.cjs

@@ -718,6 +718,12 @@ module.exports = {
         'import/no-commonjs': 'off',
       },
     },
+    {
+      files: 'resources/with-ts-node-esm.js',
+      parserOptions: {
+        sourceType: 'module',
+      },
+    },
     {
       files: '**/*.jsx',
       parserOptions: {

.mocharc.yml

@@ -4,4 +4,4 @@ check-leaks: true
 extension:
   - ts
 node-option:
-  - 'loader=ts-node/esm/transpile-only'
+  - 'import=./resources/with-ts-node-esm.js'

package.json

@@ -30,10 +30,10 @@
   },
   "scripts": {
     "preversion": "bash -c '. ./resources/checkgit.sh && npm ci --ignore-scripts'",
-    "version": "node --loader ts-node/esm resources/gen-version.ts && npm test && git add src/version.ts",
+    "version": "node --import ./resources/with-ts-node-esm.js resources/gen-version.ts && npm test && git add src/version.ts",
     "fuzzonly": "mocha --full-trace src/**/__tests__/**/*-fuzz.ts",
-    "changelog": "node --loader ts-node/esm resources/gen-changelog.ts",
-    "benchmark": "node --loader ts-node/esm resources/benchmark.ts",
+    "changelog": "node --import ./resources/with-ts-node-esm.js resources/gen-changelog.ts",
+    "benchmark": "node --import ./resources/with-ts-node-esm.js resources/benchmark.ts",
     "test": "npm run lint && npm run check && npm run testonly:cover && npm run prettier:check && npm run check:spelling && npm run check:integrations",
     "lint": "eslint --cache --max-warnings 0 --rulesdir resources/eslint-internal-rules/ .",
     "check": "tsc --pretty",
@@ -47,10 +47,10 @@
     "check:integrations": "mocha --full-trace resources/integration-test.ts",
     "serve": "docusaurus serve --dir websiteDist/ --config website/docusaurus.config.cjs",
     "start": "npm run build:website && npm run serve",
-    "build:website": "node --loader ts-node/esm resources/build-docusaurus.ts",
-    "build:npm": "node --loader ts-node/esm resources/build-npm.ts",
-    "build:deno": "node --loader ts-node/esm resources/build-deno.ts",
-    "diff:npm": "node --loader ts-node/esm resources/diff-npm-package.ts",
+    "build:website": "node --import ./resources/with-ts-node-esm.js resources/build-docusaurus.ts",
+    "build:npm": "node --import ./resources/with-ts-node-esm.js resources/build-npm.ts",
+    "build:deno": "node --import ./resources/with-ts-node-esm.js resources/build-deno.ts",
+    "diff:npm": "node --import ./resources/with-ts-node-esm.js resources/diff-npm-package.ts",
     "gitpublish:npm": "bash ./resources/gitpublish.sh npm npmDist",
     "gitpublish:deno": "bash ./resources/gitpublish.sh deno denoDist",
     "prepare": "husky"

resources/with-ts-node-esm.js

@@ -0,0 +1,5 @@
+// eslint-disable-next-line n/no-unsupported-features/node-builtins
+import { register } from 'node:module';
+import { pathToFileURL } from 'node:url';
+
+register('ts-node/esm/transpile-only', pathToFileURL('./'));