Closed as not planned
Description
Before You File a Proposal Please Confirm You Have Done The Following...
- I have searched for related issues and found none that match my proposal.
- I have searched the current rule list and found no rules that match my proposal.
- I have read the FAQ and my problem is not listed.
My proposal is suitable for this project
- My proposal specifically checks TypeScript syntax, or it proposes a check that requires type information to be accurate.
- My proposal is not a "formatting rule"; meaning it does not just enforce how code is formatted (whitespace, brace placement, etc).
- I believe my proposal would be useful to the broader TypeScript community (meaning it is not a niche proposal).
Description
This rule prevents potential erroneous implicit Function to string conversion in string interpolation expressions. Converting a function (or class itself) into string will cause function body being inserted into the string template, which could be undesirable in most of the cases.
I think we can leverage TypeScript typing information for the "Function" type checking. We don't need to cover the case where the interpolated value does not have Function type at compile-time.
Fail Cases
const formatErrorMessage = (error: unknown) => String(error);
// `formatErrorMessage` is of function type. Converting it into string results in function body being printed.
const message = "Error is {formatErrorMessage}";Pass Cases
const formatErrorMessage = (error: unknown) => String(Error);
// Call the function to return the string result.
const message1 = "Error is {formatErrorMessage(err)}.";
// Or if you are converting function into string by design.
const message2 = "Error is {String(formatErrorMessage)}.";Additional Info
No response