How can I identify instances of usage before assignment in Typescript/TSLint?

Question

How can I identify instances of usage before assignment in Typescript/TSLint?

Is there a way to receive an error when attempting to use a variable before assigning it in TypeScript? For example:

   let a: number;
   let b = a;

I have discovered that enabling the strictNullChecks option in the TS compiler can detect this issue, but it also flags null assignment violations that I am not interested in. I had hoped that TSLint would offer a rule for this specific case, but my search came up empty.

Are there any other TSLint rules or TS compiler options available for detecting the use of variables before they are assigned, aside from strictNullChecks?

typescript tslint

Answer 1

Answer №1

Finding the perfect setting that suits your needs exactly may not be possible. It's up to you to determine where on the spectrum you want to fall between these choices...

By default, opting for const is a good idea unless you absolutely need to permit multiple assignments. Remember, you cannot declare a const without initializing it:

const: number; // ERROR! const must be initialized

If you wish to catch non-assignment errors with let, enabling strict null checks through strictNullChecks is recommended.

Many of the errors you encounter can be resolved by either tightening up the code or making the expression less restrictive (allowing for null values). In my opinion, strict null checks provide the best solution.

Answer 2

Finding the perfect setting that suits your needs exactly may not be possible. It's up to you to determine where on the spectrum you want to fall between these choices...

By default, opting for const is a good idea unless you absolutely need to permit multiple assignments. Remember, you cannot declare a const without initializing it:

const: number; // ERROR! const must be initialized

If you wish to catch non-assignment errors with let, enabling strict null checks through strictNullChecks is recommended.

Many of the errors you encounter can be resolved by either tightening up the code or making the expression less restrictive (allowing for null values). In my opinion, strict null checks provide the best solution.

How can I identify instances of usage before assignment in Typescript/TSLint?

Answer №1

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