bug: Unknown compiler option 'useUnknownInCatchVariables'.

[zardoy]

Prerequisites

• I have read the Contributing Guidelines.
• I agree to follow the Code of Conduct.
• I have searched for existing issues that already report this problem, without success.

Stencil Version

v2.11.0

Current Behavior

Fails to start with this option present in tsconfig.

Expected Behavior

Not fail.

Steps to Reproduce

1. Grab https://github.com/ionic-team/stencil-component-starter.
2. Add this to compilerOptions of tsconfig:

"useUnknownInCatchVariables": true,

Code Reproduction URL

https://github.com/ionic-team/stencil-component-starter

Additional Information

For context: I can't really just remove this flag, since its in my shared tsconfig (I'm extending from it).
I don't really understand how the compiler works without installing typescript as dependency. I can only see you have locked TS version in package.json, but why?

[rwaskiewicz]

Hey @zardoy 👋

The reason this is occurring is that Stencil bundles the TypeScript compiler version for its users. The reason for this is that we need to make certain guarantees around typings, how TypeScript defines internal data structures when we compile web components and more. Because we have such strong guarantees that we need to meet, we internally pin the TypeScript version to a specific version. Currently, we pin TypeScript to v4.3

It looks like useUnknownInCatchVariables was introduced in v4.4, which explains the issue you've explained here. At this time, it doesn't look like there's an easy way to suppress that message. We're going to moving Stencil to v4.4 in the next few months. In the mean time, I would suggest not using the shared tsconfig you mentioned if at all possible. I know that can be tough for a few reasons, but unfortunately that's the best workaround I can offer at this time. Once Stencil has been released using v4.4 of TypeScript, this issue should be resolved

[zardoy]

I personally think it is a typescript failure as it doesn't provide a way to reset compilerOptions in tsconfig.
However, is there a way to make Stencil print a warning instead of crashing at startup? If there is no easy way of achieving that, I'll just wait for the next release.

[rwaskiewicz]

Not at this time, there isn't a way to configure Stencil from an end user side to print a warning in this scenario

[rwaskiewicz]

This issue has been fixed in Stencil v2.14.0 which is now available. Thanks again for the report!