fix: Don't strip underscores from variables

[gewenyu99]

Problem

Variable names in sql editor get _ stripped out, BUT if you input a space, it gets turned into an _.

This means hello_world turns into helloworld but hello world saves as hello_world.

Changes

• Tool tip to allow alphanumerics and underscore specifically.
• Frontend regex to allow _
• Both hello world and hello_world gets mapped to {variable.hello_world}
• No changes anywhere else

How did you test this code?

Manual testing

Screen.Recording.2025-10-03.at.2.35.19.PM.mov

Also tested in some queries

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Changelog: (features only) Is this feature complete?

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[github-actions]

Size Change: 0 B

Total Size: 3.07 MB

ℹ️ View Unchanged

Filename	Size
frontend/dist/toolbar.js	3.07 MB

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[ivanagas]

awesome

[Gilbert09]

Does https://github.com/PostHog/posthog/blob/master/posthog/api/insight_variable.py#L22-L24 need updating as well?

[gewenyu99]

Ooops good catch

[posthog-bot]

This PR hasn't seen activity in a week! Should it be merged, closed, or further worked on? If you want to keep it open, post a comment or remove the stale label – otherwise this will be closed in another week. If you want to permanentely keep it open, use the waiting label.

[gewenyu99]

@Gilbert09 What's the failing e2e test about?

Doesnt' look like this is related to my PR. Do I need a rebase?

Run depot/pull-action@8a922bdade29cf5facf3a13020cccd3b7a8127c2
Depot version
/opt/hostedtoolcache/depot/2.100.9/arm64/depot pull --tag posthog/posthog:98fcbfe20adddba831f3b1731e7b2b11b4b2b69f f4tglc292m
#1 pulling posthog/posthog:98fcbfe20adddba831f3b1731e7b2b11b4b2b69f
#1 ERROR: Error response from daemon: manifest for registry.depot.dev/x19jffd9zf:f4tglc292m not found: manifest unknown: Requested image not found
Error: Error response from daemon: manifest for registry.depot.dev/x19jffd9zf:f4tglc292m not found: manifest unknown: Requested image not found
Error: failed with: Error: Error response from daemon: manifest for registry.depot.dev/x19jffd9zf:f4tglc292m not found: manifest unknown: Requested image not found

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Edit: Asked around, seems unrelated, I'm gonna move this PR forward it's pretty stale. Please yell at me on Slack if I broke something so I can take credit ;)