Add Plugin options validation

[jeff-sexton]

Needs discussion:

The plugin needs to validate options after we construct the options object. We can iterate over the keys and ensure everything we expect exists and is the correct type.

Possible implementation:

  const optionsTypeValidations = {
    sharedSecret: 'string',
    verificationError: 'string',
    verificationErrorMessage: 'string',
    extractSignature: () => {},
    constructSignatureString: () => {},
    getDigest: () => {},
    digestEncoding: 'string',
    getAlgorithm: () => {},
    algorithmMap: {},
    getSignatureEncoding: () => {}
  }

  for (const [key, value] of Object.entries(optionsTypeValidations)) {
    if (!options[key] || typeof options[key] !== typeof value) {
      throw new Error(`${key} option does not exist or is not of type ${typeof value}`)
    }

[jkirkpatrick24]

This is something we definitely want. let's do some investigating on the best way to validate these inputs. A few thoughts

• Should we only validate in development mode to avoid any performance hits?
• if so, how do we want to surface the errors in a useful way for developers?
• Are there some validation libraries we can use to help us?

[jeff-sexton]

I ran across this library https://github.com/dsheiko/bycontract . It uses JSDoc expressions to configure the validation tests. It might kill two birds with one stone.