Add useQueryString to InitOptions

[zikaari]

Fixes #769

New API to control the query param behaviour:

// Disable query string processing altogether
analytics.load('<WRITE_KEY>', {
  useQueryString: false
})

// OR keep it on, but enforce validation rules
analytics.load('<WRITE_KEY>', {
  useQueryString: {
    // set a pattern for anonymous id 
    aid: /([A-Z]{10})/,
    // set a pattern for user id
    uid: /([A-Z]{6})/
  }
})

[changeset-bot]

🦋 Changeset detected

Latest commit: fa3b354

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 3 packages

Name	Type
@segment/analytics-next	Minor
@segment/analytics-core	Patch
@segment/analytics-node	Patch

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[silesky]

LGTM! We probably want to follow up with the docs team to get this feature documented.

[silesky]

Nitpick: should we return empty array instead to preserve the function signature?

Since .queryString is a public API and the function signature changed, this could be considered 'in theory' a breaking change. It would mostly affect existing typescript users who would need to update their code to handle the void case.

[zikaari]

Good catch! Let me fix that

realized had a potentially blocking question

[nfm]

Thanks for tackling this @zikaari and @silesky 🙇

I see that #775 is now merged - do you know when the functionality is likely to be available via the JS snippet? We're loading this via "https://cdn.segment.com/analytics.js/v1/" + OUR_SEGMENT_WRITE_KEY + "/analytics.min.js".