flake: TestGetUsersFilter

[flake-investigator]

CI Run Link: https://github.com/coder/coder/actions/runs/24789059592
Workflow Job: test-go-pg-17
Commit: 7904bed9476393f4627c4e12a60cf18ae3806fca by Michael Suchacz
When: 2026-04-22 16:13 UTC

What failed

• Package: github.com/coder/coder/v2/coderd
• Test: TestGetUsersFilter

Evidence from logs

Error: Received unexpected error:
POST http://127.0.0.1:41239/api/v2/users: unexpected status code 400: Validation failed.
    username: Validation failed for tag "username" with value: "uninterested-christiansen672-gh14"
Test: TestGetUsersFilter

Root cause hypothesis

• Username validation requires <=32 chars (codersdk.NameValid).
• coderdtest.RandomUsername() uses namesgenerator.UniqueNameWith("-") and can generate 28+ chars.
• In coderdtest.UsersFilter, when i%7==0 it appends -gh%d to the username. For i=14, the example name became length 33 (uninterested-christiansen672-gh14), causing the 400 validation error. This is intermittent depending on the randomly generated base name length.

Precise assignment analysis

• Failing line: coderd/coderdtest/users.go in UsersFilter where r.Username += fmt.Sprintf("-gh%d", i) is set before creating the user.
• Commands used:
  • git log --oneline -10 --follow coderd/coderdtest/users.go
• The logic for UsersFilter (including the -gh%d mutation) appears to originate in commit 24ab216dd1369aa06d70cebda0605f18008e0b7c by Asher (code-asher). Recent commits (e.g., c5f1a2f) adjust service account options but do not modify the username mutation line.
• Assigning to: @code-asher (closest owner of the UsersFilter helper and username mutation logic).

Classification

• Type: Flaky test (random data can exceed username length constraint)
• No data race indicators found
• No panic/OOM indicators found

Related issues

• None found after searching coder/internal for:
  • "TestGetUsersFilter"
  • "UsersFilter username validation failed"
  • "Validation failed" username
  • "unexpected status code 400" users

Proposed fix

• Truncate or sanitize the username in UsersFilter when appending -gh%d to ensure length <=32 (e.g., shorten base name before suffix), or generate deterministic usernames within length constraints.

Reproduction hints

• Re-run: go test ./coderd -run TestGetUsersFilter -count=50
• Intermittent failure when random username length + suffix exceeds 32 characters.