[TEST] [Bug]:

[pwizla]

Link to the documentation page or resource

https://docs.strapi.io/cms/testing

Describe the bug

Jest tests fail to run because Strapi won't load .ts config files.

Additional context

I published an example app that shows the issue to save you time, but I took the following steps to create the app:

I set up a new Strapi project using:
npx create-strapi-app@rc --skip-cloud --typescript --use-yarn --dbclient sqlite strapi-typescript-test-bug-repro
I then added Jest and its support libraries:
yarn add --dev jest ts-jest @types/jest
I initialized the Jest config using:
yarn ts-jest config:init
I then added the testPathIgnorePatterns to the Jest config as shown in the Strapi jest setup guide.

I added a strapi.ts helper file as explained in the Strapi jest setup guide. I converted it to TypeScript and used the new createStrapi function as well.

I added a config/env/test/database.ts and a config/env/production/database.ts file.

I added the following lines to my .env file:

DATABASE_FILENAME=.tmp/data.db
TEST_DATABASE_FILENAME=.tmp/test_data.db
I added tests/app.test.ts as described in the Strapi jest setup guide. This file has been converted to TypeScript as well.

Run tests with yarn test.

Expand this to see the test output...
As you can see, there are a lot of warnings like Config file not loaded, extension must be one of .js,.json): database.ts and then the tests fails because something internal to Strapi can't destructure config values.

Interestingly, if I pass the value { distDir: "dist" } to createStrapi in strapi.ts, and run yarn build before I run yarn test, the tests pass. Presumably this is because it's running the tests from the dist dir and yarn build is transpiling those files to .js files.

Suggested improvements or fixes

I would expect there to be some way to run tests under TypeScript with Strapi that didn't require a build first. This is also broken under Strapi 4 in the same way and I was trying out Strapi 5 to see if I could make it work.

Node.js version: v20.16.0
NPM version: 10.8.1 (yarn 1.22.22)
Strapi version: 5.0.0-rc.8
Database: sqlite
Operating system: macOS Sonoma 14.5
Is your project Javascript or Typescript: TypeScript
❯ yarn strapi report
yarn run v1.22.22
$ strapi report
Launched In: 141 ms
Environment: development
OS: darwin-arm64
Strapi Version: 5.0.0-rc.8
Node/Yarn Version: yarn/1.22.22 npm/? node/v20.16.0 darwin arm64
Edition: Community
Database: sqlite
[2024-08-04 18:40:08.311] info: Shutting down Strapi
[2024-08-04 18:40:08.312] info: Strapi has been shut down
✨ Done in 1.69s.

Related issue(s)/PR(s)

No response

[github-actions]

🤖 I've analyzed your question and here's what I found:

Hi there! Thank you so much for your detailed report and for sharing a reproducible example—your effort is truly appreciated and helps the community a lot. 😊

Understanding the Issue

You've run into a common challenge when using TypeScript with Strapi: Strapi does not natively load .ts config files at runtime. This is why you see warnings like Config file not loaded, extension must be one of .js,.json): database.ts and why your tests only pass after building the project (which transpiles .ts files to .js in the dist directory).

This behavior is expected: Strapi only loads JavaScript (.js) and JSON (.json) files for configuration at runtime. TypeScript files must be compiled to JavaScript before Strapi can use them, which is why running yarn build and then testing works as you described.

Current Workaround

The current, recommended approach is to:

1. Build your project (yarn build or npm run build) before running tests, so all config files are available as .js in the dist directory.

2. When starting Strapi programmatically (e.g., in your test helpers), pass the distDir option to point to the compiled code:

   const strapi = require('@strapi/strapi');
   const app = strapi.createStrapi({ distDir: './dist' });
   app.start();

   See official docs for details.

This is currently the only reliable way to ensure Strapi loads your TypeScript-based config files during tests.

Why This Happens

Strapi's runtime does not transpile TypeScript files on the fly. It expects all configuration and source files to be JavaScript at runtime. This is consistent with how Node.js works and is reflected in the Strapi TypeScript documentation.

Suggestions & Next Steps

• For now, always build before running tests when using TypeScript configs.
• If you want to avoid manual builds, you could add a pre-test script in your package.json:

  "scripts": {
    "pretest": "yarn build",
    "test": "jest --forceExit --detectOpenHandles"
  }

• If you’d like to see native support for .ts config files without a build step, please consider submitting a feature request or upvoting existing ones at Strapi Feedback.

Additional Resources

• TypeScript in Strapi projects
• Testing with Strapi
• Start Strapi programmatically with TypeScript

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If you have further questions or want to discuss this with the community, feel free to join our Discord or post on the Strapi Forum.

If you believe this is a core bug or regression, please let us know and we can flag it for the core team (@pwizla) to review for a possible transfer to the main Strapi repository.

Thanks again for your contribution and for helping make Strapi better! 🚀

📚 Relevant documentation:

• Adding TypeScript support to existing Strapi projects
• Community & Support
• Database configuration - Environment variables in database configurations
• Database migrations - Handling migrations with TypeScript code
• Deployment - General guidelines
• Frequently Asked Questions - Can I use TypeScript in a Strapi project?
• Installing from CLI - CLI installation options
• Strict requirements for configuration files
• TypeScript
• TypeScript configuration
• TypeScript Development with Strapi
• TypeScript Development with Strapi - Start Strapi programmatically
• Unit testing
• Unit testing - Create a Strapi instance
• Unit testing - Test a Strapi instance

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ℹ️ This response was generated automatically. If this doesn't fully answer your question or if you need further assistance, please mention @pwizla in a comment and a human maintainer will help you.

You can also try our interactive AI chat for more detailed assistance.

💡 For feature requests or product feedback, visit feedback.strapi.io.