<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=369152) </details> <!--IssueSummary end--> <!-- The first section "Release notes" is required if you want to have your release post blog MR auto generated. Currently in BETA, details on the **release post item generator** can be found in the handbook: https://about.gitlab.com/handbook/marketing/blog/release-posts/#release-post-item-generator and this video: https://www.youtube.com/watch?v=rfn9ebgTwKg. The next four sections: "Problem to solve", "Intended users", "User experience goal", and "Proposal", are strongly recommended in your first draft, while the rest of the sections can be filled out during the problem validation or breakdown phase. However, keep in mind that providing complete and relevant information early helps our product team validate the problem and start working on a solution. --> ### Release notes <!-- What is the problem and solution you're proposing? This content sets the overall vision for the feature and serves as the release notes that will populate in various places, including the [release post blog](https://about.gitlab.com/releases/categories/releases/) and [Gitlab project releases](https://gitlab.com/gitlab-org/gitlab/-/releases). " --> Merge Trains was introduced to allow multiple merge requests to be queued up using Merged Result Pipelines to speed up Continuous Integration and Continuous Deployment. Now, Merge Trains have been enabled for Merge Requests that have dependencies that exist both across projects and within the same project. You can now queue a merge request with a dependency and then upon successful merge of all dependencies, the Merge Request will be automatically merged. ### Problem to solve <!-- What problem do we solve? Try to define the who/what/why of the opportunity as a user story. For example, "As a (who), I want (what), so I can (why/value)." --> > People who have worked with Phabricator using a ‘stacked diff’ workflow generally love it and seek it wherever they next go. ([source](https://jg.gg/2018/09/29/stacked-diffs-versus-pull-requests/)) GitLab currently doesn't provide an intuitive way to stack diffs through Merge Requests, offering up a queueing mechanism that can provide a stacked diff experience similar to Merge Trains with Merge Request Dependencies. ### Intended users * [Delaney (Development Team Lead)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#delaney-development-team-lead) ### User experience goal <!-- What is the single user experience workflow this problem addresses? For example, "The user should be able to use the UI/API/.gitlab-ci.yml with GitLab to <perform a specific task>" https://about.gitlab.com/handbook/engineering/ux/ux-research-training/user-story-mapping/ --> Delaney, the development team lead, can review multiple merge requests and queue (stack) them up to be merged in a sequential order. This stacking can be done by making it easy to create MR dependencies on already-reviewed merges and then providing a UI to modify the order in which which the merges take place. This would be very similar to the experience of graphite.dev.  ### Proposal <!-- How are we going to solve the problem? Try to include the user journey! https://about.gitlab.com/handbook/journeys/#user-journey --> Problems to solve. 1. Allow MRs with MR Dependencies to have a button that says `Merge after all dependencies are merged` 2. Provide users with a UI that allows users to view a list of Merge Requests across projects (could be the same as a Merge Train UI) 3. Provide users with a UI that allows users to edit/add to a list of MRs across projects to order that merge request list. 4. Provide users in the UI mentioned in 2 and 3 to instantiate the Merging of all of the MRs in the list. ### Further details <!-- Include use cases, benefits, goals, or any other details that will help us understand the problem better. --> I think this could be a first iteration in the directional needs of Phabricator users that are looking for a new home and done in a way that is native to GitLab constructs.  ([source](https://www.phacility.com/phabricator/)) ### Permissions and Security <!-- What permissions are required to perform the described actions? Are they consistent with the existing permissions as documented for users, groups, and projects as appropriate? Is the proposed behavior consistent between the UI, API, and other access methods (e.g. email replies)? Consider adding checkboxes and expectations of users with certain levels of membership https://docs.gitlab.com/ee/user/permissions.html * [ ] Add expected impact to members with no access (0) * [ ] Add expected impact to Guest (10) members * [ ] Add expected impact to Reporter (20) members * [ ] Add expected impact to Developer (30) members * [ ] Add expected impact to Maintainer (40) members * [ ] Add expected impact to Owner (50) members Please consider performing a threat model for the code changes that are introduced as part of this feature. To get started, refer to our Threat Modeling handbook page https://about.gitlab.com/handbook/security/threat_modeling/#threat-modeling. Don't hesitate to reach out to the Application Security Team (`@gitlab-com/gl-security/appsec`) to discuss any security concerns. --> ### Documentation <!-- See the Feature Change Documentation Workflow https://docs.gitlab.com/ee/development/documentation/workflow.html#for-a-product-change * Add all known Documentation Requirements in this section. See https://docs.gitlab.com/ee/development/documentation/workflow.html * If this feature requires changing permissions, update the permissions document. See https://docs.gitlab.com/ee/user/permissions.html --> ### Availability & Testing <!-- This section needs to be retained and filled in during the workflow planning breakdown phase of this feature proposal, if not earlier. What risks does this change pose to our availability? How might it affect the quality of the product? What additional test coverage or changes to tests will be needed? Will it require cross-browser testing? Please list the test areas (unit, integration and end-to-end) that needs to be added or updated to ensure that this feature will work as intended. Please use the list below as guidance. * Unit test changes * Integration test changes * End-to-end test change See the Quality Engineering quad planning and test planning processes and reach out to your counterpart Software Engineer in Test for assistance. Quad Planning: https://about.gitlab.com/handbook/engineering/quality/quality-engineering/quad-planning Test Planning: https://about.gitlab.com/handbook/engineering/quality/quality-engineering/test-engineering/#test-planning --> ### Available Tier <!-- This section should be used for setting the appropriate tier that this feature will belong to. Pricing can be found here: https://about.gitlab.com/pricing/ * Free * Premium/Silver * Ultimate/Gold --> ### Feature Usage Metrics <!-- How are you going to track usage of this feature? Think about user behavior and their interaction with the product. What indicates someone is getting value from it? Create tracking issue using the Snowplow event tracking template. See https://gitlab.com/gitlab-org/gitlab/-/blob/master/.gitlab/issue_templates/Snowplow%20event%20tracking.md --> ### What does success look like, and how can we measure that? <!-- Define both the success metrics and acceptance criteria. Note that success metrics indicate the desired business outcomes, while acceptance criteria indicate when the solution is working correctly. If there is no way to measure success, link to an issue that will implement a way to measure this. Create tracking issue using the Snowplow event tracking template. See https://gitlab.com/gitlab-org/gitlab/-/blob/master/.gitlab/issue_templates/Snowplow%20event%20tracking.md --> ### What is the type of buyer? <!-- What is the buyer persona for this feature? See https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/buyer-persona/ In which enterprise tier should this feature go? See https://about.gitlab.com/handbook/product/pricing/#three-tiers --> ### Is this a cross-stage feature? <!-- Communicate if this change will affect multiple Stage Groups or product areas. We recommend always start with the assumption that a feature request will have an impact into another Group. Loop in the most relevant PM and Product Designer from that Group to provide strategic support to help align the Group's broader plan and vision, as well as to avoid UX and technical debt. https://about.gitlab.com/handbook/product/#cross-stage-features --> ### What is the competitive advantage or differentiation for this feature? ### Links / references <!-- Label reminders - you should have one of each of the following labels. Use the following resources to find the appropriate labels: - https://gitlab.com/gitlab-org/gitlab/-/labels - https://about.gitlab.com/handbook/product/categories/features/ --> <!-- triage-serverless v3 PLEASE DO NOT REMOVE THIS SECTION --> *This page may contain information related to upcoming products, features and functionality. It is important to note that the information presented is for informational purposes only, so please do not rely on the information for purchasing or planning purposes. Just like with all projects, the items mentioned on the page are subject to change or delay, and the development, release, and timing of any products, features, or functionality remain at the sole discretion of GitLab Inc.* <!-- triage-serverless v3 PLEASE DO NOT REMOVE THIS SECTION -->