fix: try to only add commonjs when running Cypress config

cli/CHANGELOG.md

@@ -1,4 +1,12 @@
 <!-- See the ../guides/writing-the-cypress-changelog.md for details on writing the changelog. -->
+## 12.17.5
+
+_Released 08/29/2023 (PENDING)_ 
+
+**Bugfixes:**
+
+- Only force CommonJS when running `ts-node` with a `TS_NODE_COMPILER` environment variable, such as when Cypress uses `ts-node` internally. This solves an issue where Cypress' internal `tsconfig` conflicts with properties set in the user's `tsconfig.json` such as `module` and `moduleResolution`. Fixes [#26308](https://github.com/cypress-io/cypress/issues/26308) and [#27448](https://github.com/cypress-io/cypress/issues/27448).
+
 ## 12.17.4
 
 _Released 08/15/2023_

packages/server/lib/plugins/child/ts_node.js

@@ -34,6 +34,9 @@ const getTsNodeOptions = (tsPath, registeredFile) => {
 
   if (process.env.TS_NODE_COMPILER) {
     try {
+      // @ts-expect-error - compilerOptions is an object we can assign properties on.
+      // It's the 'tsconfig.compilerOptions'.
+      compilerOptions.moduleResolution = 'node'
       compiler = require.resolve(process.env.TS_NODE_COMPILER, { paths: [path.dirname(registeredFile)] })
     } catch {
       // ts-node compiler not installed in project directory

packages/server/test/unit/plugins/child/ts_node_spec.js

@@ -55,6 +55,30 @@ describe('lib/plugins/child/ts_node', () => {
       })
     })
 
+    it('registers ts-node with commonjs and node moduleResolution when process.env.TS_NODE_COMPILER is set', () => {
+      process.env.TS_NODE_COMPILER = true
+      sinon.stub(typescriptObject, 'version').value('1.1.1')
+      tsNodeUtil.register('proj-root', '/path/to/plugins/file.js')
+
+      expect(tsnode.register).to.be.calledWith({
+        transpileOnly: true,
+        compiler: 'typescript/lib/typescript.js',
+        dir: '/path/to/plugins',
+        compilerOptions: {
+          module: 'commonjs',
+          moduleResolution: 'node',
+        },
+        ignore: [
+          '(?:^|/)node_modules/',
+          '/packages/telemetry/dist/span-exporters/ipc-span-exporter',
+          '/packages/telemetry/dist/span-exporters/console-trace-link-exporter',
+          '/packages/telemetry/dist/processors/on-start-span-processor',
+        ],
+      })
+
+      delete process.env.TS_NODE_COMPILER
+    })
+
     it('does not register ts-node if typescript is not installed', () => {
       resolve.typescript.returns(null)
 

system-tests/projects/config-cjs-and-esm/config-with-module-resolution-bundler/cypress.config.js

@@ -0,0 +1,7 @@
+const { defineConfig } = require('cypress')
+
+module.exports = defineConfig({
+  e2e: {
+    supportFile: false,
+  },
+})

system-tests/projects/config-cjs-and-esm/config-with-module-resolution-bundler/package.json

@@ -0,0 +1,6 @@
+{
+  "devDependencies": {
+    "typescript": "4.7.3"
+  },
+  "projectFixtureDirectory": "simple_passing"
+}

system-tests/projects/config-cjs-and-esm/config-with-module-resolution-bundler/tsconfig.json

@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "module": "es2015",
+    "moduleResolution": "bundler",
+    "types": [
+      "cypress"
+    ],
+  },
+  "include": [
+    "src"
+  ]
+}

system-tests/projects/config-cjs-and-esm/config-with-module-resolution-bundler/yarn.lock

@@ -0,0 +1,8 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+typescript@4.7.3:
+  version "4.7.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.7.3.tgz#8364b502d5257b540f9de4c40be84c98e23a129d"
+  integrity sha512-WOkT3XYvrpXx4vMMqlD+8R8R37fZkjyLGlxavMc4iB8lrl8L0DeTcHbYgw/v0N/z9wAFsgBhcsF0ruoySS22mA==

system-tests/test/config_modules_spec.ts

@@ -44,6 +44,7 @@ describe('compiles config files using the native node import', () => {
     'config-cjs-and-esm/config-with-js-tsconfig-es5',
     'config-cjs-and-esm/config-with-js-tsconfig-es3',
     'config-cjs-and-esm/config-with-js-tsconfig-es2015',
+    'config-cjs-and-esm/config-with-module-resolution-bundler',
   ].forEach((project) => {
     systemTests.it(`${project}`, {
       project,