Module export with default parameters

I am trying to export a module in Node.js with some functions in it. One of the functions have optional parameters which include default values.

module.exports = {
    foo = (a, b = 2, c = {y:0}) => {
        // Code
    },
    bar = () => { 
        // Codes 
    },
}

The functions work when it is not exported. When moved into module.exports, the following error occurs:

SyntaxError: Invalid shorthand property initializer
    at Module._compile (internal/modules/cjs/loader.js:723:23)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
    at Module.require (internal/modules/cjs/loader.js:692:17)
    at require (internal/modules/cjs/helpers.js:25:18)
    at Object.<anonymous> (/<link to this file>:2:62)
    at Module._compile (internal/modules/cjs/loader.js:778:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
    at Module.require (internal/modules/cjs/loader.js:692:17)
    at require (internal/modules/cjs/helpers.js:25:18)
    at Object.<anonymous> (/<link to server.js file>:20:18)

I am aware the parameters can be default-ed in the code of the function. Still, does default-ing parameters in brackets not work in module.exports? Any help in fixing it? Thanks.

You object notation is incorrect:

Change foo = () => {} to foo: () => {}

module.exports = {
    foo: (a, b = 2, c = {y:0}) => {
        // Code
    },
    bar: () => { 
        // Codes 
    }
}