use-worker-directive

Universal use worker functions

Install

npm i use-worker-directive

yarn add use-worker-directive

pnpm add use-worker-directive

Features

Worker functions

Like the original "use worker" directive, the compiler supports functions.

async function doStuff(x, y) {
  "use worker";
  await foo(x);
  await bar(y);
}
// also works for arrow functions

const doStuff = async (x, y) => {
  "use worker";
  await foo(x);
  await bar(y);
};

The compiler also supports async generators

async function* doStuff(x, y) {
  "use worker";
  yield foo(x);
  yield bar(y);
}

NOTE Worker functions are only valid for async functions.

Worker blocks

The original "use worker" is limited to functions, but what if you could mark block statements with the same directives?

if (someCond()) {
  'use stuff';
  await doStuff();
}

use-worker-directive supports worker blocks in almost all statements that supports it:

• if-else
• try-catch-finally
• for
• for-in
• for-of
• for await
• while
• do-while
• labeled statements

Worker blocks also supports break, continue, return and throw statements, as well as yield expressions and delegations.

for (const item of items) {
  'use worker';
  await processItem(item);
}

NOTE Worker blocks are only supported within async functions and at top-level scope (since modules now support top-level await)

Closure extraction

use-worker-directive supports closure extraction

async function foo() {
  const prefix = 'Message: ';

  async function postMessage(message) {
    'use worker';
    await addMessage(prefix + message);
  }
}

Streaming worker functions

If a worker function returns a value with a Promise, ReadableStream or AsyncIterable, those instances' values are going to be streamed through the response.

async function getMessage() {
  'use worker';
  return {
    // `getAsyncData` returns a Promise
    // On the client-side, this object is going to
    // be received immedatiely, but the value
    // to which the Promise resolves into
    // is going to be streamed after.
    message: getAsyncData(),
  };
}

Advanced serialization

use-worker-directive supports a wide range of data types, you can check the compatibility table here

Customizable directive

Integrations

• Vite

Sponsors

License

MIT © lxsmnsyc