fix(insights): validate each value of a multi-value regex filter

[evanmarshall]

This is an Ito QA mirror of PostHog#93586.

Original author: @ksvat
Pinned upstream head: f7bb6b2

This draft is for QA and build-environment experimentation and will not be merged.

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Problem

Editing a regex property filter that holds several values showed a yellow validation error reading `this.str.codePointAt is not a function`.

A `visited_page` filter ORs its regex values, so its `value` is an array. The regex validator called `RE2JS.compile(value)`, which expects a single string. Given an array, RE2JS builds a string iterator over it and `array.codePointAt` does not exist, so it threw, and the raw internal error was shown to the user.

This surfaced when editing an AI-drafted Replay Vision scanner (the drafter emits multi-value `regex` `visited_page` filters), but it affects any multi-value regex filter in the app. Pre-existing on master; not introduced by the drafter.

Changes

• `getRegexValidationError` now normalizes the value to a list and compiles each pattern, returning the first that fails. A valid multi-value regex filter validates cleanly; an invalid one reports a real regex error instead of the internal `codePointAt` message.
• Exported `getValidationError` so the pure validation logic has a unit test.

How did you test this code?

• OperatorValueSelect.test.tsx (new): a valid multi-value regex array validates without error; an array with one bad pattern reports a real error and never the `codePointAt` message; a single invalid regex still errors (no regression). 3 tests pass.
• TypeScript check and lint pass on the changed files.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Found by editing an AI-drafted scanner's page filters. Written with Claude Code. No customer conversation, ticket, or log shaped this change.

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Created with PostHog Desktop