Add unit tests for cohort validator — updateCohort and updateCohortName

🏷️ Labels

good first issue · testing · device-registry

---

📋 Background

As part of the hotfix in fix-cohort-name (which added an explicit rejection of the name field on PUT /cohorts/:cohort_id), a Copilot reviewer flagged that there are no unit tests covering the cohort validators in src/device-registry/validators/cohorts.validators.js.

Other validators in the same service already have test coverage (e.g., validators/test/ut_device.validators.js). Cohort validators should follow the same pattern to prevent regressions.

---

🎯 What needs to be done

Create a new test file:

src/device-registry/validators/test/ut_cohort.validators.js

At minimum, the following cases should be covered:

updateCohort — PUT /cohorts/:cohort_id

• Returns 400 with message "name cannot be updated via this endpoint; use PUT /cohorts/:cohort_id/name instead" when name is present in the request body
• Returns 200 (passes validation) when name is absent and other valid fields are provided (description, visibility, cohort_tags, groups, network)
• Returns 400 when cohort_id param is not a valid MongoDB ObjectId

updateCohortName — PUT /cohorts/:cohort_id/name

• Returns 400 when name is missing
• Returns 400 when confirm_update is missing or set to false
• Returns 400 when update_reason is missing, empty, or shorter than 10 characters
• Returns 400 when update_reason exceeds 500 characters
• Passes validation when all required fields (name, confirm_update: true, update_reason) are correctly provided

General

• Returns 400 when tenant query param is provided but is not in the allowed tenants list

---

📁 Reference

• Validators file: src/device-registry/validators/cohorts.validators.js
• Existing test example to follow: src/device-registry/validators/test/ut_device.validators.js
• Related hotfix PR: fix-cohort-name

---

✅ Acceptance Criteria

• New test file exists at the path above
• All cases listed are covered with assertions on both the HTTP status code and the error message
• All existing tests continue to pass
• No changes to production code are required for this issue