typedffi

Easily create types for your Deno FFI functions without any additional code.

Usage

Import the module from the Deno Third Party Modules hosting service:

import { dlopen } from "https://deno.land/x/typedffi/mod.ts";

After that, simply replace Deno.dlopen with our dlopen function.

Note: typedffi doesn’t change the behavior of Deno.dlopen with any special magic, so it still requires the --unstable flag to use.

Example

Now, let’s look at what typedffi can do for you by only adding in a as const after your FFI object:

import { dlopen } from "https://deno.land/x/typedffi/mod.ts";

const lib = dlopen(
  "YOUR_LIB",
  {
    add: {
      parameters: ["i32", "i32"],
      result: "i32",
    },
    long_async_crypto: {
      parameters: ["buffer", "u32"],
      result: "void",
      nonblocking: true,
    },
  } as const,
);

// You can now safely call `lib.symbols.add` while still having TypeScript
// typing for the function.

type AddFuncType = typeof lib.symbols.foo;
// (arg_0: number, arg_1: number) => number

// It even transforms the nonblocking functions types to be promises!

typeof lib.symbols.long_async_crypto;
// (arg_0: Uint8Array, arg_1: number) => Promise<void>

License

MIT