Correctly define ReadyCallback parameter type

[daveallie]

The existing ReadyCallback type is not valid TypeScript, resulting in a TS error when using the @fullstory/browser package.

This issue was introduced in v1.6.0.

This PR adjusts the type definition to be correct.

[luser]

Hi, thanks for the report and corresponding fix! Can you provide details of your TypeScript version and configuration? We don't have rigorous TypeScript checks in the CI on this project, but I did manual integration testing with an example project and didn't encounter this issue, so I assume it must be specific to the compiler version or options.

I want to re-verify your change with that example project but it's a very simple fix so it should be no problem to get it merged and push a point release.

[luser]

This LGTM, and worked in my local integration testing. Thanks!

[daveallie]

Apologies for not being clearer here, this is specifically for strict mode (specifically because of the noImplicitAny rule).

Smallest replicable example

package.json:

{
  "name": "fullstory-example",
  "version": "1.0.0",
  "license": "MIT",
  "dependencies": {
    "@fullstory/browser": "1.6.0"
  },
  "devDependencies": {
    "typescript": "^4.7.3"
  }
}

tsconfig.json:

{
  "compilerOptions": {
    "strict": true
  }
}

index.ts:

import * as FullStory from '@fullstory/browser';

Error:

❯ yarn tsc --noEmit
yarn run v1.22.17
$ /Users/david/tmp/fullstory-example/node_modules/.bin/tsc --noEmit
node_modules/@fullstory/browser/dist/index.d.ts:39:37 - error TS7031: Binding element 'string' implicitly has an 'any' type.

39 type ReadyCallback = ({ sessionUrl: string }) => void;
                                       ~~~~~~


Found 1 error in node_modules/@fullstory/browser/dist/index.d.ts:39

error Command failed with exit code 2.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

---

So while technically the type is parsable, it results in an unexpected definition which doesn't match the author's intent. I'd recommend running your tsc checks with strict mode enabled, it should catch small things like this, but also prevent incomplete or partial type definitions being published.

[luser]

Thanks for the clarification! I pushed out a 1.6.1 release with your fix. This will be useful when I get to #146.