Strict type-checking on a per-file basis "@ts-strict"

Search Terms

strict per file

Suggestion

Currently in the process of converting a moderate-sized javascript project to typescript. Would love to be able to enable strict type-checks on a per-file basis.

Use Cases

Enabling strict mode for the entire project is a daunting task that presents a barrier to adoption (and using typescript without strict mode turned on is like locking the doors on a convertible…it’s probably better than nothing, but it’s not gonna keep you safe).

Examples

//@ts-strict

Checklist

My suggestion meets these guidelines:

• This wouldn’t be a breaking change in existing TypeScript / JavaScript code
• This wouldn’t change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn’t a runtime feature (e.g. new expression-level syntax)

[artursvonda]

Would love to see this feature implemented as well. We have quite sizeable project and going “all strict” is not an option right now.

[kamkry]

While there are no built-in features like this in Typescript, we’ve created typescript-strict-plugin which allows you to turn on strict-mode in specific files or routes. Hope it helps!