fix: use --loader ts-node/esm for mocha test scripts

bennypowers · bennypowers · commit 71cb893203f2 · 2026-03-19T13:46:53.000+02:00
With module:nodenext, --require ts-node/register fails with
"Unknown file extension .ts". Switch to --loader ts-node/esm
with TS_NODE_TRANSPILE_ONLY=true to skip type checking.

Also restore dev-server integration test and parse5-utils test
script to master versions.

Assisted-By: Claude Opus 4.6 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/packages/browser-logs/package.json b/packages/browser-logs/package.json
@@ -26,8 +26,8 @@
   },
   "scripts": {
     "build": "tsc",
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --loader ts-node/esm --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/dev-server-core/package.json b/packages/dev-server-core/package.json
@@ -38,8 +38,8 @@
     "start:event-stream": "node demo/event-stream/start-server.js",
     "start:http2": "node demo/http2/start-server.js",
     "start:import-asset": "node demo/import-asset/start-server.js",
-    "test": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --exit --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --watch --watch-files src,test"
+    "test": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --loader ts-node/esm --exit --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     ".self-signed-dev-server-ssl.cert",
diff --git a/packages/dev-server-esbuild/package.json b/packages/dev-server-esbuild/package.json
@@ -28,8 +28,8 @@
     "build": "tsc",
     "start:demo:jsx": "es-dev-server --config demo/jsx/server.config.js",
     "start:demo:ts": "es-dev-server --config demo/ts/server.config.js",
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.ts\" --require ts-node/register --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.ts\" --require ts-node/register --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.ts\" --loader ts-node/esm --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.ts\" --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/dev-server-hmr/package.json b/packages/dev-server-hmr/package.json
@@ -28,8 +28,8 @@
     "build": "tsc",
     "start:lit-html": "wds --config demo/lit-html/server.config.mjs",
     "start:vanilla": "wds --config demo/vanilla/server.config.mjs",
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.ts\" --require ts-node/register --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.ts\" --require ts-node/register --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.ts\" --loader ts-node/esm --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.ts\" --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/dev-server-import-maps/package.json b/packages/dev-server-import-maps/package.json
@@ -26,9 +26,9 @@
   },
   "scripts": {
     "build": "tsc",
-    "test": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.ts\" --require ts-node/register",
+    "test": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.ts\" --loader ts-node/esm",
     "test:browser": "node ../test-runner/dist/bin.js test-browser/test/**/*.test.{js,html} --config test-browser/web-test-runner.config.mjs",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.ts\" --require ts-node/register --watch --watch-files src,test"
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.ts\" --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/dev-server-legacy/package.json b/packages/dev-server-legacy/package.json
@@ -27,8 +27,8 @@
   "scripts": {
     "build": "tsc",
     "start": "wds --open --config demo/server.config.mjs",
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.ts\" --require ts-node/register --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.ts\" --require ts-node/register --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.ts\" --loader ts-node/esm --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.ts\" --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/dev-server-rollup/package.json b/packages/dev-server-rollup/package.json
@@ -25,8 +25,8 @@
     "node": ">=24.0.0"
   },
   "scripts": {
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/node/**/*.test.ts\" --require ts-node/register --exit --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/node/**/*.test.ts\" --require ts-node/register --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/node/**/*.test.ts\" --loader ts-node/esm --exit --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/node/**/*.test.ts\" --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/dev-server/test/integration.test.mjs b/packages/dev-server/test/integration.test.mjs
@@ -1,10 +1,10 @@
-import { describe, it, before, after, beforeEach, afterEach } from 'node:test';
 import puppeteer from 'puppeteer';
 import path from 'path';
+import { fileURLToPath } from 'url';
 
-import { startDevServer } from '../dist/index.js';
+import { startDevServer } from '../index.mjs';
 
-const dirname = import.meta.dirname;
+const dirname = path.dirname(fileURLToPath(import.meta.url));
 
 const testCases = [
   {
@@ -53,7 +53,8 @@ describe('integration tests', () => {
   });
 
   for (const testCase of testCases) {
-    describe(`testcase ${testCase.name}`, { timeout: 30000 }, () => {
+    describe(`testcase ${testCase.name}`, function test() {
+      this.timeout(30000);
       let server;
 
       beforeEach(async () => {
@@ -68,7 +69,7 @@ describe('integration tests', () => {
         await server.stop();
       });
 
-      it('passes the in-browser tests', async () => {
+      it('passes the in-browser tests', async function it() {
         const openPath = `/demo/${testCase.name}/`;
         const browserPath = `http://${server.config.hostname}:${server.config.port}${openPath}`;
         const page = await browser.newPage();
diff --git a/packages/parse5-utils/package.json b/packages/parse5-utils/package.json
@@ -26,8 +26,8 @@
   },
   "scripts": {
     "build": "tsc",
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --watch"
+    "test:node": "mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --reporter dot",
+    "test:watch": "mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --watch"
   },
   "files": [
     "dist",
diff --git a/packages/polyfills-loader/package.json b/packages/polyfills-loader/package.json
@@ -26,9 +26,9 @@
   },
   "scripts": {
     "build": "tsc",
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --reporter dot",
-    "test:update-snapshots": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --update-snapshots",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --require ts-node/register --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --loader ts-node/esm --reporter dot",
+    "test:update-snapshots": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --loader ts-node/esm --update-snapshots",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha \"test/**/*.test.{ts,js,mjs,cjs}\" --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/rollup-plugin-html/package.json b/packages/rollup-plugin-html/package.json
@@ -28,8 +28,8 @@
     "demo:mpa": "rm -rf demo/dist && rollup -c demo/mpa/rollup.config.js --watch & npm run serve-demo",
     "demo:spa": "rm -rf demo/dist && rollup -c demo/spa/rollup.config.js --watch & npm run serve-demo",
     "serve-demo": "node ../dev-server/dist/bin.js --watch --root-dir demo/dist --app-index index.html --compatibility none --open",
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.js",
diff --git a/packages/rollup-plugin-polyfills-loader/package.json b/packages/rollup-plugin-polyfills-loader/package.json
@@ -25,9 +25,9 @@
     "node": ">=24.0.0"
   },
   "scripts": {
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --reporter dot",
-    "test:update-snapshots": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --update-snapshots",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --reporter dot",
+    "test:update-snapshots": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --update-snapshots",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/test-runner-commands/package.json b/packages/test-runner-commands/package.json
@@ -30,8 +30,8 @@
   },
   "scripts": {
     "build": "tsc",
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --watch --watch-files src,test --watch-ignore **/*.snap.js"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --watch --watch-files src,test --watch-ignore **/*.snap.js"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/test-runner-core/package.json b/packages/test-runner-core/package.json
@@ -32,8 +32,8 @@
   },
   "scripts": {
     "build": "tsc",
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/test-runner-junit-reporter/package.json b/packages/test-runner-junit-reporter/package.json
@@ -26,8 +26,8 @@
   },
   "scripts": {
     "build": "tsc",
-    "test": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --watch --watch-files src,test --reporter dot"
+    "test": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --watch --watch-files src,test --reporter dot"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/test-runner-module-mocking/package.json b/packages/test-runner-module-mocking/package.json
@@ -24,8 +24,8 @@
   },
   "scripts": {
     "build": "tsc",
-    "test:node": "mocha test/**/*.test.ts --loader=ts-node/esm --reporter dot",
-    "test:watch": "mocha test/**/*.test.ts --loader ts-node/esm --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader=ts-node/esm --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
diff --git a/packages/test-runner-visual-regression/package.json b/packages/test-runner-visual-regression/package.json
@@ -30,8 +30,8 @@
   },
   "scripts": {
     "build": "tsc",
-    "test:node": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --reporter dot",
-    "test:watch": "TS_NODE_COMPILER_OPTIONS='{\"module\":\"commonjs\",\"moduleResolution\":\"node\"}' mocha test/**/*.test.ts --require ts-node/register --watch --watch-files src,test"
+    "test:node": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --reporter dot",
+    "test:watch": "TS_NODE_TRANSPILE_ONLY=true mocha test/**/*.test.ts --loader ts-node/esm --watch --watch-files src,test"
   },
   "files": [
     "*.d.ts",
