## Summary Improve the user experience when a merge request title doesn't match the configured regex pattern. Currently, validation happens at merge-time with a `TITLE_NOT_MATCHING` status, but users need clearer guidance. ## Problem to Solve When MR title validation fails: - Users don't see the configured description explaining the required format - Error appears only at merge-time, not during creation/editing - No inline feedback to help users fix the title ## Proposal ### 1. Merge-time Error Display When MR is blocked due to `TITLE_NOT_MATCHING`: - Show the configured `mergeRequestTitleRegexDescription` prominently - Provide example of valid title format - Link to project settings (for maintainers) ### 2. Inline Validation (Optional for v1) - Show validation status while editing MR title - Real-time feedback: ✓ or ✗ next to title field - Display description text below title input ### ~~3. Creation-time Warning~~ - When creating MR with invalid title, show warning banner - Allow creation but indicate merge will be blocked - Suggest fixing title before requesting review Note: The ~frontend and ~backend regex engines are different so creation time validation is not easily done. https://gitlab.com/gitlab-org/gitlab/-/issues/582874#note_3053739652 ## Implementation Notes **Existing Status:** - Backend returns `TITLE_NOT_MATCHING` in detailed merge status - `mergeRequestTitleRegexDescription` field available via GraphQL **UI Locations to Update:** - MR creation form - MR edit title modal - MR widget (merge blocked state) - MR overview page ## Acceptance Criteria - [x] Merge widget shows clear error when title doesn't match regex - [x] Error message includes the configured description text - [x] Users can see validation status before attempting to merge - [x] Error message is actionable (tells users how to fix) - [ ] Draft/WIP status is handled appropriately in validation ## UX Considerations - [x] How to handle Draft MRs (validate with or without "Draft:" prefix?) - If it's draft, the title can be whatever https://gitlab.com/gitlab-org/gitlab/-/issues/582874#note_2940573486. If the merge check is enabled then it would prevent it from merging. - [x] Should validation be real-time or on-save? - Validation on the merge request edit/create form will happen on save. - For the form we will surface the naming convention that needs to be followed. - The merge check will be the validation since it would trigger the ~backend regex engine. - The ~frontend and ~backend regex engines are different so creation time validation is not easily done. https://gitlab.com/gitlab-org/gitlab/-/issues/582874#note_3053739652 - [x] What happens if regex is changed after MR creation? - There is an existing ~backend regex check before merging so that would catch that - Upon edit of the title that would trigger the merge check to run again which would pick up the updated regex ## Related Issues - Parent: gitlab-org#20108 (Epic) - Related: #25689 (original feature request) ## Mockups [:art: Figma](https://www.figma.com/design/JvdECCgXS5UF1Llll5AHX3/Merge-request-widgets?node-id=873-109753&t=WiLf35RIz64k1rBT-1) - 2026-02-03: Calling this "naming convention" rather than "validation pattern" in merge checks - 2026-02-05: Change the check to be "Title must match required pattern" https://gitlab.com/gitlab-org/gitlab/-/issues/582874#note_3056903471 ### Merge check settings - In https://gitlab.com/gitlab-org/gitlab/-/issues/586340#note_3029075486 we moved the settings closer to merge check but it should be part of merge check because when the user enables it - the merge will be blocked. - Settings are only saved after pressing "Save changes" | Unchecked | Checked | Validation | Filled | | ------ | ------ | ------ | ------ | | {width=847 height=600} | {width=847 height=600} | {width=847 height=600} | {width=847 height=600} | ### Merge widget Clicking on "Edit title" takes the user to the edit merge request form. | Merge check | Merge check - popover | | ------ | ------ | | {width=900 height=235} | {width=900 height=216} | ### Merge request edit/create form When merge check "Title must match required pattern" is enabled then display the description text | Description text | Description text - popover | | ------ | ------ | | {width=900 height=366} | {width=900 height=366} |