cypress-io · AtofStryker · Apr 25, 2025
diff --git a/.circleci/workflows.yml b/.circleci/workflows.yml
@@ -38,7 +38,7 @@ mainBuildFilters: &mainBuildFilters
         - /^release\/\d+\.\d+\.\d+$/
         # use the following branch as well to ensure that v8 snapshot cache updates are fully tested
         - 'update-v8-snapshot-cache-on-develop'
-        - 'remove-migration'
+        - 'feat/wbip_full_resolve_ts_config'
 
 # usually we don't build Mac app - it takes a long time
 # but sometimes we want to really confirm we are doing the right thing
@@ -49,7 +49,7 @@ macWorkflowFilters: &darwin-workflow-filters
       - equal: [ develop, << pipeline.git.branch >> ]
       # use the following branch as well to ensure that v8 snapshot cache updates are fully tested
       - equal: [ 'update-v8-snapshot-cache-on-develop', << pipeline.git.branch >> ]
-      - equal: [ 'remove-migration', << pipeline.git.branch >> ]
+      - equal: [ 'feat/wbip_full_resolve_ts_config', << pipeline.git.branch >> ]
       - matches:
           pattern: /^release\/\d+\.\d+\.\d+$/
           value: << pipeline.git.branch >>
@@ -60,7 +60,7 @@ linuxArm64WorkflowFilters: &linux-arm64-workflow-filters
       - equal: [ develop, << pipeline.git.branch >> ]
       # use the following branch as well to ensure that v8 snapshot cache updates are fully tested
       - equal: [ 'update-v8-snapshot-cache-on-develop', << pipeline.git.branch >> ]
-      - equal: [ 'remove-migration', << pipeline.git.branch >> ]
+      - equal: [ 'feat/wbip_full_resolve_ts_config', << pipeline.git.branch >> ]
       - matches:
           pattern: /^release\/\d+\.\d+\.\d+$/
           value: << pipeline.git.branch >>
@@ -83,7 +83,7 @@ windowsWorkflowFilters: &windows-workflow-filters
       - equal: [ develop, << pipeline.git.branch >> ]
       # use the following branch as well to ensure that v8 snapshot cache updates are fully tested
       - equal: [ 'update-v8-snapshot-cache-on-develop', << pipeline.git.branch >> ]
-      - equal: [ 'remove-migration', << pipeline.git.branch >> ]
+      - equal: [ 'feat/wbip_full_resolve_ts_config', << pipeline.git.branch >> ]
       - matches:
           pattern: /^release\/\d+\.\d+\.\d+$/
           value: << pipeline.git.branch >>
@@ -157,7 +157,7 @@ commands:
           name: Set environment variable to determine whether or not to persist artifacts
           command: |
             echo "Setting SHOULD_PERSIST_ARTIFACTS variable"
-            echo 'if ! [[ "$CIRCLE_BRANCH" != "develop" && "$CIRCLE_BRANCH" != "release/"* && "$CIRCLE_BRANCH" != "remove-migration" ]]; then
+            echo 'if ! [[ "$CIRCLE_BRANCH" != "develop" && "$CIRCLE_BRANCH" != "release/"* && "$CIRCLE_BRANCH" != "feat/wbip_full_resolve_ts_config" ]]; then
                 export SHOULD_PERSIST_ARTIFACTS=true
             fi' >> "$BASH_ENV"
   # You must run `setup_should_persist_artifacts` command and be using bash before running this command

diff --git a/npm/vite-dev-server/tsconfig.json b/npm/vite-dev-server/tsconfig.json
@@ -4,6 +4,7 @@
     "resolveJsonModule": true,
     "target": "ES2017" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', or 'ESNEXT'. */,
     "module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */,
+    "moduleResolution": "node",
     "lib": [
       "es2015",
       "dom"

diff --git a/npm/webpack-batteries-included-preprocessor/index.js b/npm/webpack-batteries-included-preprocessor/index.js
@@ -1,10 +1,18 @@
 const path = require('path')
 const webpack = require('webpack')
 const Debug = require('debug')
+const getTsConfig = require('get-tsconfig')
 const webpackPreprocessor = require('@cypress/webpack-preprocessor')
 
 const debug = Debug('cypress:webpack-batteries-included-preprocessor')
 
+class TsConfigNotFoundError extends Error {
+  constructor () {
+    super('No tsconfig.json found, but typescript is installed. ts-loader needs a tsconfig.json file to work. Please add one to your project in either the root or the cypress directory.')
+    this.name = 'TsConfigNotFoundError'
+  }
+}
+
 const hasTsLoader = (rules) => {
   return rules.some((rule) => {
     if (!rule.use || !Array.isArray(rule.use)) return false
@@ -16,6 +24,17 @@ const hasTsLoader = (rules) => {
 }
 
 const addTypeScriptConfig = (file, options) => {
+  // returns null if tsconfig cannot be found in the path/parent hierarchy
+  const configFile = getTsConfig.getTsconfig(file.filePath)
+
+  if (!configFile && typescriptExtensionRegex.test(file.filePath)) {
+    debug('no user tsconfig.json found. Throwing TsConfigNotFoundError')
+    // @see https://github.com/cypress-io/cypress/issues/18938
+    throw new TsConfigNotFoundError()
+  }
+
+  debug(`found user tsconfig.json at ${configFile?.path} with compilerOptions: ${JSON.stringify(configFile?.config?.compilerOptions)}`)
+
   // shortcut if we know we've already added typescript support
   if (options.__typescriptSupportAdded) return options
 
@@ -35,13 +54,6 @@ const addTypeScriptConfig = (file, options) => {
   const TsconfigPathsPlugin = require('tsconfig-paths-webpack-plugin')
   // node will try to load a projects tsconfig.json instead of the node
 
-  const getTsConfig = require('get-tsconfig')
-
-  // returns null if tsconfig cannot be found in the path/parent hierarchy
-  const configFile = getTsConfig.getTsconfig(file.filePath)
-
-  configFile ? debug(`found user tsconfig.json at ${configFile?.path} with compilerOptions: ${JSON.stringify(configFile?.config?.compilerOptions)}`) : debug('no user tsconfig.json found')
-
   webpackOptions.module.rules.push({
     test: /\.tsx?$/,
     exclude: [/node_modules/],
@@ -50,6 +62,10 @@ const addTypeScriptConfig = (file, options) => {
         loader: require.resolve('ts-loader'),
         options: {
           compiler: options.typescript,
+          // pass in the resolved compiler options from the tsconfig file into ts-loader to most accurately transpile the code
+          ...(configFile ? {
+            compilerOptions: configFile.config.compilerOptions,
+          } : {}),
           logLevel: 'error',
           silent: true,
           transpileOnly: true,

diff --git a/npm/webpack-batteries-included-preprocessor/test/unit/index.spec.js b/npm/webpack-batteries-included-preprocessor/test/unit/index.spec.js
@@ -67,8 +67,16 @@ describe('webpack-batteries-included-preprocessor', () => {
       mock.stop('@cypress/webpack-preprocessor')
     })
 
-    it('always returns loader options even if there is an error discovering the user\'s tsconfig.json', () => {
-      getTsConfigMock.returns(null)
+    it('correctly passes the options in the user\'s tsconfig.json options into ts-loader', () => {
+      getTsConfigMock.returns({
+        config: {
+          compilerOptions: {
+            module: 'ESNext',
+            moduleResolution: 'Bundler',
+          },
+          path: '/foo/tsconfig.json',
+        },
+      })
 
       const preprocessorCB = preprocessor({
         typescript: true,
@@ -89,8 +97,28 @@ describe('webpack-batteries-included-preprocessor', () => {
       expect(tsLoader.options.silent).to.be.true
       expect(tsLoader.options.transpileOnly).to.be.true
 
-      // compilerOptions are set by `@cypress/webpack-preprocessor` if ts-loader is present
-      expect(tsLoader.options.compilerOptions).to.be.undefined
+      // compilerOptions are overridden (sourceMap=true) by `@cypress/webpack-preprocessor` if ts-loader is present
+      expect(tsLoader.options.compilerOptions).to.deep.equal({
+        module: 'ESNext',
+        moduleResolution: 'Bundler',
+      })
+    })
+
+    // @see https://github.com/cypress-io/cypress/issues/18938. ts-loader needs a tsconfig.json file to work.
+    it('throws an error if the user\'s tsconfig.json is not found', () => {
+      getTsConfigMock.returns(null)
+
+      const preprocessorCB = preprocessor({
+        typescript: true,
+        webpackOptions,
+      })
+
+      expect(() => {
+        return preprocessorCB({
+          filePath: 'foo.ts',
+          outputPath: '.js',
+        })
+      }).to.throw('No tsconfig.json found, but typescript is installed. ts-loader needs a tsconfig.json file to work. Please add one to your project in either the root or the cypress directory.')
     })
   })
 })
diff --git a/npm/webpack-dev-server/tsconfig.json b/npm/webpack-dev-server/tsconfig.json
@@ -4,6 +4,7 @@
     "resolveJsonModule": true,
     "target": "ES2017" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', or 'ESNEXT'. */,
     "module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */,
+    "moduleResolution": "node",
     "lib": [
       "es2015",
       "dom"

diff --git a/system-tests/__snapshots__/no_tsconfig_ts_js_mix.ts.js b/system-tests/__snapshots__/no_tsconfig_ts_js_mix.ts.js
@@ -0,0 +1,115 @@
+exports['e2e no tsconfig ts js mix / fails with no tsconfig.json error'] = `
+
+====================================================================================================
+
+  (Run Starting)
+
+  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
+  │ Cypress:    1.2.3                                                                              │
+  │ Browser:    FooBrowser 88                                                                      │
+  │ Specs:      1 found (spec.cy.ts)                                                               │
+  │ Searched:   cypress/e2e/spec.cy.ts                                                             │
+  └────────────────────────────────────────────────────────────────────────────────────────────────┘
+
+
+────────────────────────────────────────────────────────────────────────────────────────────────────
+
+  Running:  spec.cy.ts                                                                      (1 of 1)
+
+Oops...we found an error preparing this test file:
+
+  > cypress/e2e/spec.cy.ts
+
+The error was:
+
+TsConfigNotFoundError: No tsconfig.json found, but typescript is installed. ts-loader needs a tsconfig.json file to work. Please add one to your project in either the root or the cypress directory.
+      [stack trace lines]
+
+This occurred while Cypress was compiling and bundling your test code. This is usually caused by:
+
+- A missing file or dependency
+- A syntax error in the file or one of its dependencies
+
+Fix the error in your code and re-run your tests.
+
+  (Results)
+
+  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
+  │ Tests:        0                                                                                │
+  │ Passing:      0                                                                                │
+  │ Failing:      1                                                                                │
+  │ Pending:      0                                                                                │
+  │ Skipped:      0                                                                                │
+  │ Screenshots:  0                                                                                │
+  │ Video:        false                                                                            │
+  │ Duration:     X seconds                                                                        │
+  │ Spec Ran:     spec.cy.ts                                                                       │
+  └────────────────────────────────────────────────────────────────────────────────────────────────┘
+
+
+====================================================================================================
+
+  (Run Finished)
+
+
+       Spec                                              Tests  Passing  Failing  Pending  Skipped  
+  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
+  │ ✖  spec.cy.ts                               XX:XX        -        -        1        -        - │
+  └────────────────────────────────────────────────────────────────────────────────────────────────┘
+    ✖  1 of 1 failed (100%)                     XX:XX        -        -        1        -        -  
+
+
+`
+
+exports['e2e no tsconfig ts js mix / passes'] = `
+
+====================================================================================================
+
+  (Run Starting)
+
+  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
+  │ Cypress:    1.2.3                                                                              │
+  │ Browser:    FooBrowser 88                                                                      │
+  │ Specs:      1 found (spec.cy.js)                                                               │
+  │ Searched:   cypress/e2e/spec.cy.js                                                             │
+  └────────────────────────────────────────────────────────────────────────────────────────────────┘
+
+
+────────────────────────────────────────────────────────────────────────────────────────────────────
+
+  Running:  spec.cy.js                                                                      (1 of 1)
+
+
+  ✓ is true
+
+  1 passing
+
+
+  (Results)
+
+  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
+  │ Tests:        1                                                                                │
+  │ Passing:      1                                                                                │
+  │ Failing:      0                                                                                │
+  │ Pending:      0                                                                                │
+  │ Skipped:      0                                                                                │
+  │ Screenshots:  0                                                                                │
+  │ Video:        false                                                                            │
+  │ Duration:     X seconds                                                                        │
+  │ Spec Ran:     spec.cy.js                                                                       │
+  └────────────────────────────────────────────────────────────────────────────────────────────────┘
+
+
+====================================================================================================
+
+  (Run Finished)
+
+
+       Spec                                              Tests  Passing  Failing  Pending  Skipped  
+  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
+  │ ✔  spec.cy.js                               XX:XX        1        1        -        -        - │
+  └────────────────────────────────────────────────────────────────────────────────────────────────┘
+    ✔  All specs passed!                        XX:XX        1        1        -        -        -  
+
+
+`
diff --git a/system-tests/projects/no-tsconfig-ts-js-mix/cypress.config.js b/system-tests/projects/no-tsconfig-ts-js-mix/cypress.config.js
@@ -0,0 +1,7 @@
+module.exports = {
+  e2e: {
+    setupNodeEvents (on, config) {
+      return config
+    },
+  },
+}
diff --git a/system-tests/projects/no-tsconfig-ts-js-mix/cypress/e2e/spec.cy.js b/system-tests/projects/no-tsconfig-ts-js-mix/cypress/e2e/spec.cy.js
@@ -0,0 +1,3 @@
+it('is true', () => {
+  expect(true).to.be.true
+})
diff --git a/system-tests/projects/no-tsconfig-ts-js-mix/cypress/e2e/spec.cy.ts b/system-tests/projects/no-tsconfig-ts-js-mix/cypress/e2e/spec.cy.ts
@@ -0,0 +1,3 @@
+it('is true', () => {
+  expect(true).to.be.true
+})
diff --git a/system-tests/projects/no-tsconfig-ts-js-mix/cypress/support/e2e.js b/system-tests/projects/no-tsconfig-ts-js-mix/cypress/support/e2e.js
@@ -0,0 +1 @@
+// intentionally left empty
diff --git a/system-tests/projects/no-tsconfig-ts-js-mix/package.json b/system-tests/projects/no-tsconfig-ts-js-mix/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "no-tsconfig-ts-js-mix",
+  "version": "0.0.0-test",
+  "devDependencies": {
+    "typescript": "^5.6.0"
+  }
+}
diff --git a/system-tests/projects/no-tsconfig-ts-js-mix/yarn.lock b/system-tests/projects/no-tsconfig-ts-js-mix/yarn.lock
@@ -0,0 +1,8 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+typescript@^5.6.0:
+  version "5.8.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.8.3.tgz#92f8a3e5e3cf497356f4178c34cd65a7f5e8440e"
+  integrity sha512-p1diW6TqL9L07nNxvRMM7hMMw4c5XOo/1ibL4aAIGmSAt9slTE1Xgw5KWuof2uTOvCg9BY7ZRi+GaF+7sfgPeQ==
diff --git a/system-tests/test/no_tsconfig_ts_js_mix.ts b/system-tests/test/no_tsconfig_ts_js_mix.ts
@@ -0,0 +1,25 @@
+import systemTests from '../lib/system-tests'
+
+describe('e2e no tsconfig ts js mix', () => {
+  systemTests.setup()
+
+  systemTests.it('passes', {
+    spec: 'spec.cy.js',
+    browser: 'chrome',
+    project: 'no-tsconfig-ts-js-mix',
+    snapshot: true,
+  })
+
+  systemTests.it('fails with no tsconfig.json error', {
+    spec: 'spec.cy.ts',
+    browser: 'chrome',
+    project: 'no-tsconfig-ts-js-mix',
+    snapshot: true,
+    expectedExitCode: 1,
+    async onRun (exec, browserName) {
+      const { stdout } = await exec()
+
+      expect(stdout).to.include('TsConfigNotFoundError: No tsconfig.json found, but typescript is installed. ts-loader needs a tsconfig.json file to work. Please add one to your project in either the root or the cypress directory.')
+    },
+  })
+})