Typings don't seem to match usage.

I’ve set up as per the example in the README:

// CompareWorker is loaded through webpack worker-loader
const workerBase = new CompareWorker();
const CompareWork = Comlink.wrap<Compare>(workerBase);
const CompareOr = await new CompareWork();

But when I go to create the instance I get this TS error on line 4:

Cannot use 'new' with an expression whose type lacks a call or construct signature.ts(2351)

The return type from wrap is an interface with the methods of the class passed through the function. As this doesn’t have a call signature it prompts with an error. TS still compiles fine, but the logged errors are frustrating when the usage is correct.

[surma]

I am not sure what your types are, but

const CompareWork = Comlink.wrap<Compare>(workerBase);

means that CompareWork will be an class instance of Compare. My hunch is that you actually want CompareWork to be the class Compare with which you can create new instances using new.

The typical fix for this is

const CompareWork = Comlink.wrap<typeof Compare>(workerBase);

[surma]

For future reference, if you think something is wrong, please put an example on a Glitch. These partial code snippets are not very helpful for me to figure out where things are going wrong. That being said, I think this is all working as intended and you are merely getting your types mixed up a bit 😄

It all depends on what you are passing to expose().

• If you are using Comlink.expose(MyClass), you are exposing the class and the corresponding counterpart is const thing = Comlink.wrap<typeof MyClass>(worker). thing is now the class (not an instance!), meaning you can’t call any methods (like increment) until you create an instance using const instance = await new thing().
• If you are using Comlink.expose(new MyClass()), you are exposing an instance and the corresponding counterpart is const thing = Comlink.wrap<My class>(worker). thing is now an instance and you can call methods straight away.

If you still think this is wrong please re-open and give me a full sample showing me the wrong behavior.