fix(explore): add !has filter when drilling down into no value group

[SafinMahmud]

Fixes #106948

Problem

When clicking "View Samples" from a group with no value (e.g. user.id
is empty), the filter was silently skipped because the code had no handler
for undefined values. This caused the samples page to show all spans
instead of only spans matching the no-value group.

Solution

Add a !has:<groupBy> filter when the group by value is undefined/null,
which correctly filters for spans where that field is not present.

Changes

• static/app/views/explore/utils.tsx: Added else if (!defined(value))
  branch to handle undefined group by values
• static/app/views/explore/utils.spec.tsx: Added test case covering the
  no-value drill down scenario

[nsdeschenes]

Everything looks great here, thank you very much for your contribution!

[getsantry]

This pull request has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you add the label WIP, I will leave it alone unless WIP is removed ... forever!

---

"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀

[SafinMahmud]

Friendly bump, still active. Already approved and waiting on merge.​​​​​​​​​​​​​​​​

[nsdeschenes]

Hey @SafinMahmud, sorry for the delay getting caught up in different things!

Can you verify this is still an issue in production? I haven't been able to repro this.

[SafinMahmud]

Sorry for the late reply. I don't have access to a production org with the right data to verify. I verified the fix through the unit test covering the no-value drill down scenario. I wasn't able to reproduce in a local environment due to span ingestion setup.

[sentry]

Bug: The generateTargetQuery function silently ignores numeric groupBy values when drilling down into samples, causing the drilldown to show unfiltered results instead of the expected filtered data.
_{Severity: MEDIUM}

Suggested Fix

Add a generic handler to the generateTargetQuery function to process numeric values. This can be done by adding an else if (typeof value === 'number') block that appends the filter condition newQuery.push(${groupBy}:${value}); to the query, similar to how string values are handled.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: static/app/views/explore/utils.tsx#L324-L326

Potential issue: The `generateTargetQuery` function in
`static/app/views/explore/utils.tsx` lacks a handler for numeric values in `groupBy`
columns. While there are specific handlers for fields like `project.id` and a generic
handler for strings, any other numeric value (e.g., `http.status_code` or custom numeric
attributes) will fall through all conditions. Consequently, when a user groups by a
numeric attribute and clicks "View Samples", the numeric filter is silently skipped.
This leads to the samples page showing all spans instead of the correctly filtered
subset, which is incorrect and misleading behavior.

_{Did we get this right? 👍 / 👎 to inform future reviews.}