#### **Context** This is a follow-up to !214145 which fixes branch names with `#` characters breaking file preview on page reload. While that MR addresses the `#` character specifically, there are other special characters that GitLab allows in branch names (per [branch naming documentation](https://docs.gitlab.com/user/project/repository/branches/#name-your-branch)) that may cause similar issues. #### **Current Behavior** When a branch contains special characters that aren't properly URL-encoded in the frontend router, the file preview shows a blank page with no indication of what went wrong. Users have no way to understand why the page failed to load or how to recover. **Example**: A branch named `!@#$%/)(` will break the file preview, displaying an empty page. #### **Desired Behavior** 1. **Detect** when a branch name contains special characters that can't be properly handled 2. **Display** a user-friendly error message explaining what went wrong 3. **Provide** a way for users to navigate back or try alternative actions 4. **Log** the issue for debugging purposes #### **Acceptance Criteria** - [ ] When navigating to a file on a branch with unsupported special characters, an error message is displayed instead of a blank page - [ ] Error message clearly indicates the issue is related to the branch name - [ ] Users can navigate back to the repository or branch list from the error state - [ ] Error handling works for both tree view (`/-/tree/`) and blob view (`/-/blob/`) - [ ] Tests cover error scenarios with various special character combinations #### **Implementation Notes** **Recommended Approach:** 1. Enhance the `encodeRepositoryPath()` utility to handle all special characters that could break routing 2. Add validation in the router to detect when a branch name can't be properly encoded 3. Create an error component or error state to display when encoding fails 4. Add comprehensive tests for edge cases **Characters to Consider:** - Currently handled: `#` (via !214145) - Should handle: `?`, `&`, and other URL-special characters - May need graceful degradation for: `!`, `@`, `$`, `%`, etc. **Related Files:** - `app/assets/javascripts/repository/utils/url_utility.js` - Encoding logic - `app/assets/javascripts/repository/router.js` - Route definitions - `app/assets/javascripts/repository/pages/blob.vue` - Blob view - `app/assets/javascripts/repository/pages/tree.vue` - Tree view #### **Related Issues** - Related to: !214145, #579389