More precise typescript types

[matheus23]

Summary

The typescript types generated from wasm-bindgen aren't very precise, see for example:

/**
* Returns the name and metadata of the direct children of a directory.
* @param {Array<any>} path_segments
* @param {any} store
* @returns {Promise<any>}
*/
  ls(path_segments: Array<any>, store: any): Promise<any>;

I think path_segments could be Array<string>, and store: ForeignBlockStore?

Problem

This helps orient users using TS types for autocompletion in IDEs, for example. Also makes sure that there are fewer accidental runtime errors.

Impact

Not big, only people using the wnfs npm package. Which is mostly me at the moment. I think it's fair to expect anyone else to use webnative, not wnfs directly.

Solution

I don't know. Maybe a setting in wasm-bindgen? Something that needs to be configured? Is that perhaps an issue with wasm-bindgen and they need to fix it?

[appcypher]

Found a solution to this.

rustwasm/wasm-bindgen#1197 (comment)

We could have a types.rs file for the type annotations

#[wasm_bindgen(typescript_custom_section)]
const TS_BLOCKSTORE: &'static str = r#"
export interface BlockStore {
    putBlock(bytes: string): Promise<Uint8Array>;
    getBlock(cid: Uint8Array): Promise<Uint8Array>;
}
"#;

#[wasm_bindgen]
extern "C" {
    #[wasm_bindgen(typescript_type = "BlockStore")]
    pub type BlockStore;

    // ...
}