Improve error message when attempting to compile TypeScript file and typescript support is not enabled

[chrisbreiding]

Current behavior:

If you don't pass the typescript option, but have TypeScript files, it results in a syntax error.

SyntaxError: Unexpected token (3:10) while parsing /path/to/project/cypress/integration/typescript_spec.ts while parsing file: /path/to/project/cypress/integration/typescript_spec.ts

See also this issue comment.

This is particularly problematic in the default Cypress behavior, since we try to pass the typescript option automatically by auto-detecting it. If we fail to find it and don't pass the option, but the user has TypeScript files, it fails at runtime with the above cryptic syntax error.

Desired behavior:

We should error early if attempting to compile a .ts or .tsx file and the typescript option is not set. In the error message, we can make it clear what went wrong and provide remediation options.

How to reproduce:

Create a TypeScript spec (cypress/integration/typescript_spec.js) and add some TypeScript-specific syntax:

interface Foo {
  baz: string
}

Run Cypress and it will fail with a syntax error.

[mike-hogan]

@chrisbreiding this suggests that if I pass the typescript option, things will work. Where and how do I pass this option?

Thanks

[chrisbreiding]

You can use it by using this package directly. Check out the installation and usage directions the the typescript directions.

Cypress uses this package under the hood and tries to auto-detect the path to your typescript installation, but it seems that may not work in all cases, so providing the path manually might make it work.

[chrisbreiding]

🎉 This issue has been resolved in version 3.0.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀