Filtering of merge requests by deployments data

This adds support for filtering merge requests by the environment name
and deployment times, in addition to the existing support of filtering
merge requests by a deployment ID. This means you can now get merge
requests that match an environment name, deployment ID, or are deployed
before/after a given date and time. These filters can be combined as
well.

Filtering merge requests by deployments data makes it easy to see what
has been deployed, and when. In addition, you can apply all the other
merge requests filters such as a list of labels to filter by.

This new feature is hidden behind the "deployment_filters" feature flag,
which is disabled by default. This feature flag is a global flag. Merge
requests can be retrieved for both projects and groups, making it
difficult to determine what to scope the feature flag to. So we take the
easy way: it's either enabled for all, or disabled for all. For
something as simple as a few additional filters this should not pose any
problems.

See https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/1246 for
more information.

app/assets/javascripts/filtered_search/add_extra_tokens_for_merge_requests.js

@@ -108,4 +108,44 @@ export default (IssuableTokenKeys, disableTargetBranchFilter = false) => {
   IssuableTokenKeys.tokenKeys.splice(tokenPosition, 0, ...[approvedBy.token]);
   IssuableTokenKeys.tokenKeysWithAlternative.splice(tokenPosition, 0, ...[approvedBy.token]);
   IssuableTokenKeys.conditions.push(...approvedBy.condition);
+
+  if (gon?.features?.deploymentFilters) {
+    const environmentToken = {
+      formattedKey: __('Environment'),
+      key: 'environment',
+      type: 'string',
+      param: '',
+      symbol: '',
+      icon: 'cloud-gear',
+      tag: 'environment',
+    };
+
+    const deployedBeforeToken = {
+      formattedKey: __('Deployed-before'),
+      key: 'deployed-before',
+      type: 'string',
+      param: '',
+      symbol: '',
+      icon: 'clock',
+      tag: 'deployed_before',
+    };
+
+    const deployedAfterToken = {
+      formattedKey: __('Deployed-after'),
+      key: 'deployed-after',
+      type: 'string',
+      param: '',
+      symbol: '',
+      icon: 'clock',
+      tag: 'deployed_after',
+    };
+
+    IssuableTokenKeys.tokenKeys.push(environmentToken, deployedBeforeToken, deployedAfterToken);
+
+    IssuableTokenKeys.tokenKeysWithAlternative.push(
+      environmentToken,
+      deployedBeforeToken,
+      deployedAfterToken,
+    );
+  }
 };

app/assets/javascripts/filtered_search/available_dropdown_mappings.js

@@ -15,6 +15,7 @@ export default class AvailableDropdownMappings {
     labelsEndpoint,
     milestonesEndpoint,
     releasesEndpoint,
+    environmentsEndpoint,
     groupsOnly,
     includeAncestorGroups,
     includeDescendantGroups,
@@ -24,6 +25,7 @@ export default class AvailableDropdownMappings {
     this.labelsEndpoint = labelsEndpoint;
     this.milestonesEndpoint = milestonesEndpoint;
     this.releasesEndpoint = releasesEndpoint;
+    this.environmentsEndpoint = environmentsEndpoint;
     this.groupsOnly = groupsOnly;
     this.includeAncestorGroups = includeAncestorGroups;
     this.includeDescendantGroups = includeDescendantGroups;
@@ -149,6 +151,16 @@ export default class AvailableDropdownMappings {
         },
         element: this.container.querySelector('#js-dropdown-target-branch'),
       },
+      environment: {
+        reference: null,
+        gl: DropdownNonUser,
+        extraArguments: {
+          endpoint: this.getEnvironmentsEndpoint(),
+          symbol: '',
+          preprocessing: data => data.map(env => ({ title: env })),
+        },
+        element: this.container.querySelector('#js-dropdown-environment'),
+      },
     };
   }
 
@@ -194,6 +206,10 @@ export default class AvailableDropdownMappings {
     return mergeUrlParams(params, endpoint);
   }
 
+  getEnvironmentsEndpoint() {
+    return `${this.environmentsEndpoint}.json`;
+  }
+
   getGroupId() {
     return this.filteredSearchInput.getAttribute('data-group-id') || '';
   }

app/assets/javascripts/filtered_search/filtered_search_dropdown_manager.js

@@ -13,6 +13,7 @@ export default class FilteredSearchDropdownManager {
     labelsEndpoint = '',
     milestonesEndpoint = '',
     releasesEndpoint = '',
+    environmentsEndpoint = '',
     epicsEndpoint = '',
     tokenizer,
     page,
@@ -29,6 +30,7 @@ export default class FilteredSearchDropdownManager {
     this.milestonesEndpoint = removeTrailingSlash(milestonesEndpoint);
     this.releasesEndpoint = removeTrailingSlash(releasesEndpoint);
     this.epicsEndpoint = removeTrailingSlash(epicsEndpoint);
+    this.environmentsEndpoint = removeTrailingSlash(environmentsEndpoint);
     this.tokenizer = tokenizer;
     this.filteredSearchTokenKeys = filteredSearchTokenKeys || FilteredSearchTokenKeys;
     this.filteredSearchInput = this.container.querySelector('.filtered-search');

app/assets/javascripts/filtered_search/filtered_search_manager.js

@@ -110,6 +110,7 @@ export default class FilteredSearchManager {
         labelsEndpoint = '',
         milestonesEndpoint = '',
         releasesEndpoint = '',
+        environmentsEndpoint = '',
         epicsEndpoint = '',
       } = this.filteredSearchInput.dataset;
 
@@ -118,6 +119,7 @@ export default class FilteredSearchManager {
         labelsEndpoint,
         milestonesEndpoint,
         releasesEndpoint,
+        environmentsEndpoint,
         epicsEndpoint,
         tokenizer: this.tokenizer,
         page: this.page,

app/controllers/groups_controller.rb

@@ -30,6 +30,7 @@ class GroupsController < Groups::ApplicationController
 
   before_action do
     push_frontend_feature_flag(:vue_issuables_list, @group)
+    push_frontend_feature_flag(:deployment_filters)
   end
 
   before_action do
@@ -53,7 +54,7 @@ class GroupsController < Groups::ApplicationController
 
   feature_category :audit_events, [:activity]
   feature_category :issue_tracking, [:issues, :issues_calendar, :preview_markdown]
-  feature_category :code_review, [:merge_requests]
+  feature_category :code_review, [:merge_requests, :unfoldered_environment_names]
   feature_category :projects, [:projects]
   feature_category :importers, [:export, :download_export]
 
@@ -179,6 +180,16 @@ class GroupsController < Groups::ApplicationController
     end
   end
 
+  def unfoldered_environment_names
+    return render_404 unless Feature.enabled?(:deployment_filters)
+
+    respond_to do |format|
+      format.json do
+        render json: EnvironmentNamesFinder.new(@group, current_user).execute
+      end
+    end
+  end
+
   protected
 
   def render_show_html

app/controllers/projects/merge_requests_controller.rb

@@ -47,6 +47,7 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
 
   before_action do
     push_frontend_feature_flag(:vue_issuable_sidebar, @project.group)
+    push_frontend_feature_flag(:deployment_filters)
   end
 
   around_action :allow_gitaly_ref_name_caching, only: [:index, :show, :discussions]

app/controllers/projects_controller.rb

@@ -56,6 +56,7 @@ class ProjectsController < Projects::ApplicationController
   feature_category :issue_tracking, [:preview_markdown, :new_issuable_address]
   feature_category :importers, [:export, :remove_export, :generate_new_export, :download_export]
   feature_category :audit_events, [:activity]
+  feature_category :code_review, [:unfoldered_environment_names]
 
   def index
     redirect_to(current_user ? root_path : explore_root_path)
@@ -315,6 +316,16 @@ class ProjectsController < Projects::ApplicationController
     end
   end
 
+  def unfoldered_environment_names
+    return render_404 unless Feature.enabled?(:deployment_filters)
+
+    respond_to do |format|
+      format.json do
+        render json: EnvironmentNamesFinder.new(@project, current_user).execute
+      end
+    end
+  end
+
   private
 
   # Render project landing depending of which features are available

app/finders/environment_names_finder.rb

+# frozen_string_literal: true
+
+# Finder for obtaining the unique environment names of a project or group.
+#
+# This finder exists so that the merge requests "environments" filter can be
+# populated with a unique list of environment names. If we retrieve _just_ the
+# environments, duplicates may be present (e.g. multiple projects in a group
+# having a "staging" environment).
+#
+# In addition, this finder only produces unfoldered environments. We do this
+# because when searching for environments we want to exclude review app
+# environments.
+class EnvironmentNamesFinder
+  attr_reader :project_or_group, :current_user
+
+  def initialize(project_or_group, current_user)
+    @project_or_group = project_or_group
+    @current_user = current_user
+  end
+
+  def execute
+    all_environments.unfoldered.order_by_name.pluck_unique_names
+  end
+
+  def all_environments
+    if project_or_group.is_a?(Namespace)
+      namespace_environments
+    else
+      project_environments
+    end
+  end
+
+  def namespace_environments
+    projects =
+      project_or_group.all_projects.public_or_visible_to_user(current_user)
+
+    Environment.for_project(projects)
+  end
+
+  def project_environments
+    if current_user.can?(:read_environment, project_or_group)
+      project_or_group.environments
+    else
+      Environment.none
+    end
+  end
+end

app/finders/merge_requests_finder.rb

@@ -33,7 +33,17 @@ class MergeRequestsFinder < IssuableFinder
   include MergedAtFilter
 
   def self.scalar_params
-    @scalar_params ||= super + [:wip, :draft, :target_branch, :merged_after, :merged_before, :approved_by_ids]
+    @scalar_params ||= super + [
+      :approved_by_ids,
+      :deployed_after,
+      :deployed_before,
+      :draft,
+      :environment,
+      :merged_after,
+      :merged_before,
+      :target_branch,
+      :wip
+    ]
   end
 
   def self.array_params
@@ -46,12 +56,13 @@ class MergeRequestsFinder < IssuableFinder
 
   def filter_items(_items)
     items = by_commit(super)
-    items = by_deployment(items)
     items = by_source_branch(items)
     items = by_draft(items)
     items = by_target_branch(items)
     items = by_merged_at(items)
     items = by_approvals(items)
+    items = by_deployments(items)
+
     by_source_project_id(items)
   end
 
@@ -85,17 +96,21 @@ class MergeRequestsFinder < IssuableFinder
 
     items.where(target_branch: target_branch)
   end
+  # rubocop: enable CodeReuse/ActiveRecord
 
   def source_project_id
     @source_project_id ||= params[:source_project_id].presence
   end
 
+  # rubocop: disable CodeReuse/ActiveRecord
   def by_source_project_id(items)
     return items unless source_project_id
 
     items.where(source_project_id: source_project_id)
   end
+  # rubocop: enable CodeReuse/ActiveRecord
 
+  # rubocop: disable CodeReuse/ActiveRecord
   def by_draft(items)
     draft_param = params[:draft] || params[:wip]
 
@@ -107,6 +122,7 @@ class MergeRequestsFinder < IssuableFinder
       items
     end
   end
+  # rubocop: enable CodeReuse/ActiveRecord
 
   # WIP is deprecated in favor of Draft. Currently both options are supported
   def wip_match(table)
@@ -126,12 +142,14 @@ class MergeRequestsFinder < IssuableFinder
       .or(table[:title].matches('(Draft)%'))
   end
 
+  # rubocop: disable CodeReuse/ActiveRecord
   def by_deployment(items)
     return items unless deployment_id
 
     items.includes(:deployment_merge_requests)
          .where(deployment_merge_requests: { deployment_id: deployment_id })
   end
+  # rubocop: enable CodeReuse/ActiveRecord
 
   def deployment_id
     @deployment_id ||= params[:deployment_id].presence
@@ -149,6 +167,33 @@ class MergeRequestsFinder < IssuableFinder
   def items_assigned_to(items, user)
     MergeRequest.from_union([super, items.reviewer_assigned_to(user)])
   end
+
+  def by_deployments(items)
+    # Until this feature flag is enabled permanently, we retain the old
+    # filtering behaviour/code.
+    return by_deployment(items) unless Feature.enabled?(:deployment_filters)
+
+    env = params[:environment]
+    before = params[:deployed_before]
+    after = params[:deployed_after]
+    id = params[:deployment_id]
+
+    return items if !env && !before && !after && !id
+
+    # Each filter depends on the same JOIN+WHERE. To prevent this JOIN+WHERE
+    # from being duplicated for every filter, we only produce it once. The
+    # filter methods in turn expect the JOIN+WHERE to already be present.
+    #
+    # This approach ensures that query performance doesn't degrade as the number
+    # of deployment related filters increases.
+    deploys = DeploymentMergeRequest.join_deployments_for_merge_requests
+    deploys = deploys.by_deployment_id(id) if id
+    deploys = deploys.deployed_to(env) if env
+    deploys = deploys.deployed_before(before) if before
+    deploys = deploys.deployed_after(after) if after
+
+    items.where_exists(deploys)
+  end
 end
 
 MergeRequestsFinder.prepend_if_ee('EE::MergeRequestsFinder')

app/helpers/search_helper.rb

@@ -262,11 +262,15 @@ module SearchHelper
       opts[:data]['labels-endpoint'] = project_labels_path(@project)
       opts[:data]['milestones-endpoint'] = project_milestones_path(@project)
       opts[:data]['releases-endpoint'] = project_releases_path(@project)
+      opts[:data]['environments-endpoint'] =
+        unfoldered_environment_names_project_path(@project)
     elsif @group.present?
       opts[:data]['group-id'] = @group.id
       opts[:data]['labels-endpoint'] = group_labels_path(@group)
       opts[:data]['milestones-endpoint'] = group_milestones_path(@group)
       opts[:data]['releases-endpoint'] = group_releases_path(@group)
+      opts[:data]['environments-endpoint'] =
+        unfoldered_environment_names_group_path(@group)
     else
       opts[:data]['labels-endpoint'] = dashboard_labels_path
       opts[:data]['milestones-endpoint'] = dashboard_milestones_path

app/models/deployment_merge_request.rb

@@ -3,4 +3,25 @@
 class DeploymentMergeRequest < ApplicationRecord
   belongs_to :deployment, optional: false
   belongs_to :merge_request, optional: false
+
+  def self.join_deployments_for_merge_requests
+    joins(deployment: :environment)
+      .where('deployment_merge_requests.merge_request_id = merge_requests.id')
+  end
+
+  def self.by_deployment_id(id)
+    where('deployments.id = ?', id)
+  end
+
+  def self.deployed_to(name)
+    where('environments.name = ?', name)
+  end
+
+  def self.deployed_after(time)
+    where('deployments.finished_at > ?', time)
+  end
+
+  def self.deployed_before(time)
+    where('deployments.finished_at < ?', time)
+  end
 end

app/models/environment.rb

@@ -68,6 +68,7 @@ class Environment < ApplicationRecord
   scope :order_by_last_deployed_at_desc, -> do
     order(Gitlab::Database.nulls_last_order("(#{max_deployment_id_sql})", 'DESC'))
   end
+  scope :order_by_name, -> { order('environments.name ASC') }
 
   scope :in_review_folder, -> { where(environment_type: "review") }
   scope :for_name, -> (name) { where(name: name) }
@@ -120,6 +121,10 @@ class Environment < ApplicationRecord
     pluck(:name)
   end
 
+  def self.pluck_unique_names
+    pluck('DISTINCT(environments.name)')
+  end
+
   def self.find_or_create_by_name(name)
     find_or_create_by(name: name)
   end

app/views/shared/issuable/_search_bar.html.haml

@@ -161,6 +161,11 @@
                     %li.filter-dropdown-item
                       %button.btn.btn-link.js-data-value.monospace
                         {{title}}
+              #js-dropdown-environment.filtered-search-input-dropdown-menu.dropdown-menu
+                %ul.filter-dropdown{ data: { dynamic: true, dropdown: true } }
+                  %li.filter-dropdown-item
+                    %button.btn.btn-link.js-data-value{ type: 'button' }
+                      {{title}}
 
               = render_if_exists 'shared/issuable/filter_weight', type: type
 

config/feature_flags/development/deployment_filters.yml

+---
+name: deployment_filters
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/44041
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/267561
+type: development
+group: group::source code
+default_enabled: false

config/routes/group.rb

@@ -17,6 +17,7 @@ constraints(::Constraints::GroupUrlConstrainer.new) do
       put :transfer, as: :transfer_group # rubocop:disable Cop/PutGroupRoutesUnderScope
       post :export, as: :export_group # rubocop:disable Cop/PutGroupRoutesUnderScope
       get :download_export, as: :download_export_group # rubocop:disable Cop/PutGroupRoutesUnderScope
+      get :unfoldered_environment_names, as: :unfoldered_environment_names_group # rubocop:disable Cop/PutGroupRoutesUnderScope
 
       # TODO: Remove as part of refactor in https://gitlab.com/gitlab-org/gitlab-foss/issues/49693
       get 'shared', action: :show, as: :group_shared # rubocop:disable Cop/PutGroupRoutesUnderScope

config/routes/project.rb

@@ -578,6 +578,7 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
         get :activity
         get :refs
         put :new_issuable_address
+        get :unfoldered_environment_names
       end
     end
     # rubocop: enable Cop/PutProjectRoutesUnderScope

doc/api/merge_requests.md

@@ -72,6 +72,9 @@ Parameters:
 | `in`                            | string         | no       | Modify the scope of the `search` attribute. `title`, `description`, or a string joining them with comma. Default is `title,description` |
 | `wip`                           | string         | no       | Filter merge requests against their `wip` status. `yes` to return *only* WIP merge requests, `no` to return *non* WIP merge requests |
 | `not`                           | Hash           | no       | Return merge requests that do not match the parameters supplied. Accepts: `labels`, `milestone`, `author_id`, `author_username`, `assignee_id`, `assignee_username`, `my_reaction_emoji` |
+| `environment`                   | string         | no       | Returns merge requests deployed to the given environment
+| `deployed_before`               | datetime       | no       | Return merge requests deployed before the given date/time
+| `deployed_after`                | datetime       | no       | Return merge requests deployed after the given date/time
 
 NOTE: **Note:**
 [Starting in GitLab 13.0](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/31890),

ee/app/assets/javascripts/filtered_search/available_dropdown_mappings.js

@@ -11,6 +11,7 @@ export default class AvailableDropdownMappings {
     milestonesEndpoint,
     epicsEndpoint,
     releasesEndpoint,
+    environmentsEndpoint,
     groupsOnly,
     includeAncestorGroups,
     includeDescendantGroups,
@@ -21,6 +22,7 @@ export default class AvailableDropdownMappings {
     this.milestonesEndpoint = milestonesEndpoint;
     this.epicsEndpoint = epicsEndpoint;
     this.releasesEndpoint = releasesEndpoint;
+    this.environmentsEndpoint = environmentsEndpoint;
     this.groupsOnly = groupsOnly;
     this.includeAncestorGroups = includeAncestorGroups;
     this.includeDescendantGroups = includeDescendantGroups;

lib/api/helpers/merge_requests_helpers.rb

@@ -73,6 +73,13 @@ module API
         optional :not, type: Hash, desc: 'Parameters to negate' do
           use :merge_requests_negatable_params
         end
+
+        optional :deployed_before,
+          'Return merge requests deployed before the given date/time'
+        optional :deployed_after,
+          'Return merge requests deployed after the given date/time'
+        optional :environment,
+          'Returns merge requests deployed to the given environment'
       end
 
       params :optional_scope_param do

locale/gitlab.pot

@@ -8972,6 +8972,12 @@ msgstr ""
 msgid "Deployed to"
 msgstr ""
 
+msgid "Deployed-after"
+msgstr ""
+
+msgid "Deployed-before"
+msgstr ""
+
 msgid "Deploying to"
 msgstr ""
 

spec/features/merge_requests/user_filters_by_deployments_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'Merge Requests > User filters by deployments', :js do
+  include FilteredSearchHelpers
+
+  let!(:project) { create(:project, :public, :repository) }
+  let!(:user) { project.creator }
+  let!(:gstg) { create(:environment, project: project, name: 'gstg') }
+  let!(:gprd) { create(:environment, project: project, name: 'gprd') }
+
+  let(:mr1) do
+    create(
+      :merge_request,
+      :simple,
+      :merged,
+      author: user,
+      source_project: project,
+      target_project: project
+    )
+  end
+
+  let(:mr2) do
+    create(
+      :merge_request,
+      :simple,
+      :merged,
+      author: user,
+      source_project: project,
+      target_project: project
+    )
+  end
+
+  let(:deploy1) do
+    create(
+      :deployment,
+      :success,
+      deployable: nil,
+      environment: gstg,
+      project: project,
+      sha: mr1.diff_head_sha,
+      finished_at: Time.utc(2020, 10, 1, 0, 0)
+    )
+  end
+
+  let(:deploy2) do
+    create(
+      :deployment,
+      :success,
+      deployable: nil,
+      environment: gprd,
+      project: project,
+      sha: mr2.diff_head_sha,
+      finished_at: Time.utc(2020, 10, 2, 0, 0)
+    )
+  end
+
+  before do
+    deploy1.link_merge_requests(MergeRequest.where(id: mr1.id))
+    deploy2.link_merge_requests(MergeRequest.where(id: mr2.id))
+
+    sign_in(user)
+    visit(project_merge_requests_path(project, state: :merged))
+  end
+
+  describe 'filtering by deployed-before' do
+    it 'applies the filter' do
+      input_filtered_search('deployed-before:=2020-10-02')
+
+      expect(page).to have_issuable_counts(open: 0, merged: 1, all: 1)
+      expect(page).to have_content mr1.title
+    end
+  end
+
+  describe 'filtering by deployed-after' do
+    it 'applies the filter' do
+      input_filtered_search('deployed-after:=2020-10-01')
+
+      expect(page).to have_issuable_counts(open: 0, merged: 1, all: 1)
+      expect(page).to have_content mr2.title
+    end
+  end
+
+  describe 'filtering by environment' do
+    it 'applies the filter' do
+      input_filtered_search('environment:=gstg')
+
+      expect(page).to have_issuable_counts(open: 0, merged: 1, all: 1)
+      expect(page).to have_content mr1.title
+    end
+  end
+end

spec/finders/environment_names_finder_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe EnvironmentNamesFinder do
+  describe '#execute' do
+    let!(:group) { create(:group) }
+    let!(:project1) { create(:project, :public, namespace: group) }
+    let!(:project2) { create(:project, :private, namespace: group) }
+    let!(:user) { create(:user) }
+
+    before do
+      create(:environment, name: 'gstg', project: project1)
+      create(:environment, name: 'gprd', project: project1)
+      create(:environment, name: 'gprd', project: project2)
+      create(:environment, name: 'gcny', project: project2)
+    end
+
+    context 'using a group and a group member' do
+      it 'returns environment names for all projects' do
+        group.add_developer(user)
+
+        names = described_class.new(group, user).execute
+
+        expect(names).to eq(%w[gcny gprd gstg])
+      end
+    end
+
+    context 'using a group and a guest' do
+      it 'returns environment names for all public projects' do
+        names = described_class.new(group, user).execute
+
+        expect(names).to eq(%w[gprd gstg])
+      end
+    end
+
+    context 'using a public project and a project member' do
+      it 'returns all the unique environment names' do
+        project1.team.add_developer(user)
+
+        names = described_class.new(project1, user).execute
+
+        expect(names).to eq(%w[gprd gstg])
+      end
+    end
+
+    context 'using a public project and a guest' do
+      it 'returns all the unique environment names' do
+        names = described_class.new(project1, user).execute
+
+        expect(names).to eq(%w[gprd gstg])
+      end
+    end
+
+    context 'using a private project and a guest' do
+      it 'returns all the unique environment names' do
+        names = described_class.new(project2, user).execute
+
+        expect(names).to be_empty
+      end
+    end
+  end
+end

spec/finders/merge_requests_finder_spec.rb

@@ -510,6 +510,83 @@ RSpec.describe MergeRequestsFinder do
           expect(merge_requests).to contain_exactly(old_merge_request, new_merge_request)
         end
       end
+
+      context 'filtering by the merge request deployments' do
+        let(:gstg) { create(:environment, project: project4, name: 'gstg') }
+        let(:gprd) { create(:environment, project: project4, name: 'gprd') }
+
+        let(:mr1) do
+          create(
+            :merge_request,
+            :simple,
+            :merged,
+            author: user,
+            source_project: project4,
+            target_project: project4
+          )
+        end
+
+        let(:mr2) do
+          create(
+            :merge_request,
+            :simple,
+            :merged,
+            author: user,
+            source_project: project4,
+            target_project: project4
+          )
+        end
+
+        let(:deploy1) do
+          create(
+            :deployment,
+            :success,
+            deployable: nil,
+            environment: gstg,
+            project: project4,
+            sha: mr1.diff_head_sha,
+            finished_at: Time.utc(2020, 10, 1, 12, 0)
+          )
+        end
+
+        let(:deploy2) do
+          create(
+            :deployment,
+            :success,
+            deployable: nil,
+            environment: gprd,
+            project: project4,
+            sha: mr2.diff_head_sha,
+            finished_at: Time.utc(2020, 10, 2, 15, 0)
+          )
+        end
+
+        before do
+          deploy1.link_merge_requests(MergeRequest.where(id: mr1.id))
+          deploy2.link_merge_requests(MergeRequest.where(id: mr2.id))
+        end
+
+        it 'filters merge requests deployed to a given environment' do
+          mrs = described_class.new(user, environment: 'gstg').execute
+
+          expect(mrs).to eq([mr1])
+        end
+
+        it 'filters merge requests deployed before a given date' do
+          mrs =
+            described_class.new(user, deployed_before: '2020-10-02').execute
+
+          expect(mrs).to eq([mr1])
+        end
+
+        it 'filters merge requests deployed after a given date' do
+          mrs = described_class
+            .new(user, deployed_after: '2020-10-01 12:00')
+            .execute
+
+          expect(mrs).to eq([mr2])
+        end
+      end
     end
 
     describe '#row_count', :request_store do

spec/requests/api/merge_requests_spec.rb

@@ -856,6 +856,55 @@ RSpec.describe API::MergeRequests do
       expect(json_response.first['id']).to eq merge_request_closed.id
     end
 
+    context 'when filtering by deployments' do
+      let_it_be(:mr) do
+        create(:merge_request, :merged, source_project: project, target_project: project)
+      end
+
+      before do
+        env = create(:environment, project: project, name: 'staging')
+        deploy = create(:deployment, :success, environment: env, deployable: nil)
+
+        deploy.link_merge_requests(MergeRequest.where(id: mr.id))
+      end
+
+      it 'supports getting merge requests deployed to an environment' do
+        get api(endpoint_path, user), params: { environment: 'staging' }
+
+        expect(json_response.first['id']).to eq mr.id
+      end
+
+      it 'does not return merge requests for an environment without deployments' do
+        get api(endpoint_path, user), params: { environment: 'bla' }
+
+        expect_empty_array_response
+      end
+
+      it 'supports getting merge requests deployed after a date' do
+        get api(endpoint_path, user), params: { deployed_after: '1990-01-01' }
+
+        expect(json_response.first['id']).to eq mr.id
+      end
+
+      it 'does not return merge requests not deployed after a given date' do
+        get api(endpoint_path, user), params: { deployed_after: '2100-01-01' }
+
+        expect_empty_array_response
+      end
+
+      it 'supports getting merge requests deployed before a date' do
+        get api(endpoint_path, user), params: { deployed_before: '2100-01-01' }
+
+        expect(json_response.first['id']).to eq mr.id
+      end
+
+      it 'does not return merge requests not deployed before a given date' do
+        get api(endpoint_path, user), params: { deployed_before: '1990-01-01' }
+
+        expect_empty_array_response
+      end
+    end
+
     context 'a project which enforces all discussions to be resolved' do
       let_it_be(:project) { create(:project, :repository, only_allow_merge_if_all_discussions_are_resolved: true) }