Move to ESM

[tommy-mitchell]

Per #82.

• Converts project from CJS to ESM.
• Uses Object.hasOwn() instead of Object.prototype.hasOwnProperty.call()
  • Bumps minimum Node.js version to v16.9 accordingly (MDN compatibility list) and updates CI matrix
• Updates code style to use xo (based on configs from AVA)
• Updates dependencies (except for well-known-symbols)
• Includes a build of lodash with only the required functions
  • Removes _.flattenDeep in favor of Array#flat(Infinity)

A few tests are failing, seems to have to do with serialization and object pointers.

[tommy-mitchell]

Perhaps we could use smoldash instead of lodash for _.cloneDeep and _.merge: https://github.com/marvinhagemeister/smoldash/blob/51b5872d8c0887e25e0ccd54555b35f0d7ecb2a8/src/index.ts#L286-L339

Related, what is _.isLength doing? Is it needed?

[novemberborn]

• Updates dependencies (except for well-known-symbols)

That library has transferred actually (not sure if it's been republished yet). There's definitely more well-known symbols out there but maybe there's a better way to encode them.

Perhaps we could use smoldash instead of lodash for _.cloneDeep and _.merge: marvinhagemeister/smoldash@51b5872/src/index.ts#L286-L339

I'm not bothered either way. There may also be some APIs we could use, e.g. the structured clone implementation in the node:v8 module.

Related, what is _.isLength doing? Is it needed?

Looks like it's a heuristic for identifying when to treat an object as a list (array). But it could be inlined:

https://github.com/lodash/lodash/blob/ddfd9b11a0126db2302cb70ec9973b66baec0975/lodash.js#L11713-L11716

• Bumps minimum Node.js version to v16.9 accordingly (MDN compatibility list) and updates CI matrix

I'd go with 18. 16 is end of life in 9 days.