fix: generate BigInt type as bigint

[avinassh]

The type of BigInt in Typescript is bigint (not BigInt). bigint is the type and BigInt is the constructor.

Here is the typescript docs for reference: https://typescriptlang.org/docs/handbook/release-notes/typescript-3-2.html#bigint

BigInt support in TypeScript introduces a new primitive type called the bigint (all lowercase). You can get a bigint by calling the BigInt() function or by writing out a BigInt literal by adding an n to the end of any integer numeric literal

let foo: bigint = BigInt(100); // the BigInt function
let bar: bigint = 100n; // a BigInt literal

function fibonacci(n: bigint) {
...
}

I need this to stop VSCode to complain :)

[oscartbeaumont]

Good catch although be careful using bigint types due to the loss of precision that can happen with JSON.parse!

[avinassh]

@oscartbeaumont thank you for the quick merge!

you are right, I did run into the bug. What is the right way to handle bigint types? (I am using specta with tauri-specta)

[oscartbeaumont]

Your best bet is to convert it to a string using Serde and manually decode it to a BigInt on the frontend. It's annoying but the issue is with JSON.parse so nothing Specta can do about it.

You can do it like so:

#[derive(Serialize, Type)]
struct Header {
	#[specta(type = String)]
	#[serde(serialize_with = "as_string")]
	timestamp: u128,
}

fn as_string<T: ToString, S>(x: &T, s: S) -> Result<S::Ok, S::Error>
where
	S: Serializer,
{
	s.serialize_str(&x.to_string())
}