Merge branch 'squash-commit-message-template' into 'master'

Add squash commit message template

See merge request gitlab-org/gitlab!74340

app/assets/javascripts/vue_merge_request_widget/components/states/commit_edit.vue

@@ -41,7 +41,6 @@ export default {
         rows="7"
         @input="$emit('input', $event.target.value)"
       ></textarea>
-      <slot name="text-muted"></slot>
     </div>
   </li>
 </template>

app/assets/javascripts/vue_merge_request_widget/components/states/ready_to_merge.vue

@@ -181,9 +181,16 @@ export default {
       return this.mr.canRemoveSourceBranch;
     },
     commitTemplateHelpPage() {
-      return helpPagePath('user/project/merge_requests/commit_templates.md', {
-        anchor: 'merge-commit-message-template',
-      });
+      return helpPagePath('user/project/merge_requests/commit_templates.md');
+    },
+    commitTemplateHintText() {
+      if (this.shouldShowSquashEdit && this.shouldShowMergeEdit) {
+        return this.$options.i18n.mergeAndSquashCommitTemplatesHintText;
+      }
+      if (this.shouldShowSquashEdit) {
+        return this.$options.i18n.squashCommitTemplateHintText;
+      }
+      return this.$options.i18n.mergeCommitTemplateHintText;
     },
     commits() {
       if (this.glFeatures.mergeRequestWidgetGraphql) {
@@ -509,6 +516,12 @@ export default {
     mergeCommitTemplateHintText: s__(
       'mrWidget|To change this default message, edit the template for merge commit messages. %{linkStart}Learn more.%{linkEnd}',
     ),
+    squashCommitTemplateHintText: s__(
+      'mrWidget|To change this default message, edit the template for squash commit messages. %{linkStart}Learn more.%{linkEnd}',
+    ),
+    mergeAndSquashCommitTemplatesHintText: s__(
+      'mrWidget|To change these default messages, edit the templates for both the merge and squash commit messages. %{linkStart}Learn more.%{linkEnd}',
+    ),
   },
 };
 </script>
@@ -674,23 +687,22 @@ export default {
                     :label="__('Merge commit message')"
                     input-id="merge-message-edit"
                     class="gl-m-0! gl-p-0!"
-                  >
-                    <template #text-muted>
-                      <p class="form-text text-muted">
-                        <gl-sprintf :message="$options.i18n.mergeCommitTemplateHintText">
-                          <template #link="{ content }">
-                            <gl-link
-                              :href="commitTemplateHelpPage"
-                              class="inline-link"
-                              target="_blank"
-                            >
-                              {{ content }}
-                            </gl-link>
-                          </template>
-                        </gl-sprintf>
-                      </p>
-                    </template>
-                  </commit-edit>
+                  />
+                  <li class="gl-m-0! gl-p-0!">
+                    <p class="form-text text-muted">
+                      <gl-sprintf :message="commitTemplateHintText">
+                        <template #link="{ content }">
+                          <gl-link
+                            :href="commitTemplateHelpPage"
+                            class="inline-link"
+                            target="_blank"
+                          >
+                            {{ content }}
+                          </gl-link>
+                        </template>
+                      </gl-sprintf>
+                    </p>
+                  </li>
                 </ul>
               </div>
               <div
@@ -792,19 +804,18 @@ export default {
               v-model="commitMessage"
               :label="__('Merge commit message')"
               input-id="merge-message-edit"
-            >
-              <template #text-muted>
-                <p class="form-text text-muted">
-                  <gl-sprintf :message="$options.i18n.mergeCommitTemplateHintText">
-                    <template #link="{ content }">
-                      <gl-link :href="commitTemplateHelpPage" class="inline-link" target="_blank">
-                        {{ content }}
-                      </gl-link>
-                    </template>
-                  </gl-sprintf>
-                </p>
-              </template>
-            </commit-edit>
+            />
+            <li>
+              <p class="form-text text-muted">
+                <gl-sprintf :message="commitTemplateHintText">
+                  <template #link="{ content }">
+                    <gl-link :href="commitTemplateHelpPage" class="inline-link" target="_blank">
+                      {{ content }}
+                    </gl-link>
+                  </template>
+                </gl-sprintf>
+              </p>
+            </li>
           </ul>
         </commits-header>
       </template>

app/controllers/projects_controller.rb

@@ -452,6 +452,7 @@ class ProjectsController < Projects::ApplicationController
       :packages_enabled,
       :service_desk_enabled,
       :merge_commit_template,
+      :squash_commit_template,
       project_setting_attributes: project_setting_attributes
     ] + [project_feature_attributes: project_feature_attributes]
   end

app/graphql/types/project_type.rb

@@ -386,6 +386,11 @@ module Types
           null: true,
           description: 'Template used to create merge commit message in merge requests.'
 
+    field :squash_commit_template,
+          GraphQL::Types::String,
+          null: true,
+          description: 'Template used to create squash commit message in merge requests.'
+
     def label(title:)
       BatchLoader::GraphQL.for(title).batch(key: project) do |titles, loader, args|
         LabelsFinder

app/models/merge_request.rb

@@ -1317,7 +1317,7 @@ class MergeRequest < ApplicationRecord
 
   def default_merge_commit_message(include_description: false)
     if self.target_project.merge_commit_template.present? && !include_description
-      return ::Gitlab::MergeRequests::MergeCommitMessage.new(merge_request: self).message
+      return ::Gitlab::MergeRequests::CommitMessageGenerator.new(merge_request: self).merge_message
     end
 
     closes_issues_references = visible_closing_issues_for.map do |issue|
@@ -1340,6 +1340,10 @@ class MergeRequest < ApplicationRecord
   end
 
   def default_squash_commit_message
+    if self.target_project.squash_commit_template.present?
+      return ::Gitlab::MergeRequests::CommitMessageGenerator.new(merge_request: self).squash_message
+    end
+
     title
   end
 

app/models/project.rb

@@ -452,6 +452,7 @@ class Project < ApplicationRecord
     to: :project_setting
   delegate :active?, to: :prometheus_integration, allow_nil: true, prefix: true
   delegate :merge_commit_template, :merge_commit_template=, to: :project_setting, allow_nil: true
+  delegate :squash_commit_template, :squash_commit_template=, to: :project_setting, allow_nil: true
 
   delegate :log_jira_dvcs_integration_usage, :jira_dvcs_server_last_sync_at, :jira_dvcs_cloud_last_sync_at, to: :feature_usage
 

app/models/project_setting.rb

@@ -13,6 +13,7 @@ class ProjectSetting < ApplicationRecord
   self.primary_key = :project_id
 
   validates :merge_commit_template, length: { maximum: 500 }
+  validates :squash_commit_template, length: { maximum: 500 }
 
   def squash_enabled_by_default?
     %w[always default_on].include?(squash_option)

app/views/projects/_merge_request_merge_commit_template.html.haml

@@ -12,6 +12,6 @@
     %p.form-text.text-muted
       = s_('ProjectSettings|Maximum 500 characters.')
       = s_('ProjectSettings|Supported variables:')
-      - Gitlab::MergeRequests::MergeCommitMessage::PLACEHOLDERS.keys.each do |placeholder|
+      - Gitlab::MergeRequests::CommitMessageGenerator::PLACEHOLDERS.keys.each do |placeholder|
         %code
           = "%{#{placeholder}}".html_safe

app/views/projects/_merge_request_settings.html.haml

@@ -12,5 +12,7 @@
 
 = render 'projects/merge_request_merge_commit_template', project: @project, form: form
 
+= render 'projects/merge_request_squash_commit_template', project: @project, form: form
+
 - if @project.forked?
   = render 'projects/merge_request_target_project_settings', project: @project, form: form

app/views/projects/_merge_request_squash_commit_template.html.haml

+- form = local_assigns.fetch(:form)
+
+.form-group
+  %b= s_('ProjectSettings|Squash commit message template')
+  %p.text-secondary
+    - configure_the_squash_commit_message_help_link_url = help_page_path('user/project/merge_requests/commit_templates.md', anchor: 'squash-commit-message-template')
+    - configure_the_squash_commit_message_help_link_start = '<a href="%{url}" target="_blank" rel="noopener noreferrer">'.html_safe % { url: configure_the_squash_commit_message_help_link_url }
+    = s_('ProjectSettings|The commit message used when squashing commits. %{link_start}Learn more about syntax and variables.%{link_end}').html_safe % { link_start: configure_the_squash_commit_message_help_link_start, link_end: '</a>'.html_safe }
+  .mb-2
+    = form.text_area :squash_commit_template, class: 'form-control gl-form-input', rows: 8, maxlength: 500, placeholder: '%{title}'
+    %p.form-text.text-muted
+      = s_('ProjectSettings|Maximum 500 characters.')
+      = s_('ProjectSettings|Supported variables:')
+      - Gitlab::MergeRequests::CommitMessageGenerator::PLACEHOLDERS.keys.each do |placeholder|
+        %code
+          = "%{#{placeholder}}".html_safe

db/migrate/20211111164025_add_squash_commit_template_to_project_settings.rb

+# frozen_string_literal: true
+
+class AddSquashCommitTemplateToProjectSettings < Gitlab::Database::Migration[1.0]
+  enable_lock_retries!
+
+  def change
+    add_column :project_settings, :squash_commit_template, :text # rubocop:disable Migration/AddLimitToTextColumns
+  end
+end

db/migrate/20211111164047_add_squash_commit_template_limit_to_project_settings.rb

+# frozen_string_literal: true
+
+class AddSquashCommitTemplateLimitToProjectSettings < Gitlab::Database::Migration[1.0]
+  disable_ddl_transaction!
+
+  def up
+    add_text_limit :project_settings, :squash_commit_template, 500
+  end
+
+  def down
+    remove_text_limit :project_settings, :squash_commit_template
+  end
+end

db/schema_migrations/20211111164025

+d78fe687517e14ff67dc76eff63391e33b73d29446d2a0445595175c7cd6806a
\ No newline at end of file

db/schema_migrations/20211111164047

+c8ed7f8c0f818156dba9c25be848da97d4eb6dbf0aa9c48f87e940f3ca0967d9
\ No newline at end of file

db/structure.sql

@@ -18299,7 +18299,9 @@ CREATE TABLE project_settings (
     warn_about_potentially_unwanted_characters boolean DEFAULT true NOT NULL,
     merge_commit_template text,
     has_shimo boolean DEFAULT false NOT NULL,
+    squash_commit_template text,
     CONSTRAINT check_3a03e7557a CHECK ((char_length(previous_default_branch) <= 4096)),
+    CONSTRAINT check_b09644994b CHECK ((char_length(squash_commit_template) <= 500)),
     CONSTRAINT check_bde223416c CHECK ((show_default_award_emojis IS NOT NULL)),
     CONSTRAINT check_eaf7cfb6a7 CHECK ((char_length(merge_commit_template) <= 500))
 );

doc/api/graphql/reference/index.md

@@ -12867,6 +12867,7 @@ Represents vulnerability finding of a security report on the pipeline.
 | <a id="projectservicedeskenabled"></a>`serviceDeskEnabled` | [`Boolean`](#boolean) | Indicates if the project has service desk enabled. |
 | <a id="projectsharedrunnersenabled"></a>`sharedRunnersEnabled` | [`Boolean`](#boolean) | Indicates if shared runners are enabled for the project. |
 | <a id="projectsnippetsenabled"></a>`snippetsEnabled` | [`Boolean`](#boolean) | Indicates if Snippets are enabled for the current user. |
+| <a id="projectsquashcommittemplate"></a>`squashCommitTemplate` | [`String`](#string) | Template used to create squash commit message in merge requests. |
 | <a id="projectsquashreadonly"></a>`squashReadOnly` | [`Boolean!`](#boolean) | Indicates if `squashReadOnly` is enabled. |
 | <a id="projectsshurltorepo"></a>`sshUrlToRepo` | [`String`](#string) | URL to connect to the project via SSH. |
 | <a id="projectstarcount"></a>`starCount` | [`Int!`](#int) | Number of times the project has been starred. |

doc/api/projects.md

@@ -183,6 +183,7 @@ When the user is authenticated and `simple` is not set this returns something li
     "autoclose_referenced_issues": true,
     "suggestion_commit_message": null,
     "merge_commit_template": null,
+    "squash_commit_template": null,
     "marked_for_deletion_at": "2020-04-03", // Deprecated and will be removed in API v5 in favor of marked_for_deletion_on
     "marked_for_deletion_on": "2020-04-03",
     "statistics": {
@@ -300,6 +301,7 @@ When the user is authenticated and `simple` is not set this returns something li
     "autoclose_referenced_issues": true,
     "suggestion_commit_message": null,
     "merge_commit_template": null,
+    "squash_commit_template": null,
     "statistics": {
       "commit_count": 12,
       "storage_size": 2066080,
@@ -470,6 +472,7 @@ GET /users/:user_id/projects
     "autoclose_referenced_issues": true,
     "suggestion_commit_message": null,
     "merge_commit_template": null,
+    "squash_commit_template": null,
     "marked_for_deletion_at": "2020-04-03", // Deprecated and will be removed in API v5 in favor of marked_for_deletion_on
     "marked_for_deletion_on": "2020-04-03",
     "statistics": {
@@ -587,6 +590,7 @@ GET /users/:user_id/projects
     "autoclose_referenced_issues": true,
     "suggestion_commit_message": null,
     "merge_commit_template": null,
+    "squash_commit_template": null,
     "statistics": {
       "commit_count": 12,
       "storage_size": 2066080,
@@ -714,6 +718,7 @@ Example response:
     "autoclose_referenced_issues": true,
     "suggestion_commit_message": null,
     "merge_commit_template": null,
+    "squash_commit_template": null,
     "statistics": {
       "commit_count": 37,
       "storage_size": 1038090,
@@ -826,6 +831,7 @@ Example response:
     "autoclose_referenced_issues": true,
     "suggestion_commit_message": null,
     "merge_commit_template": null,
+    "squash_commit_template": null,
     "statistics": {
       "commit_count": 12,
       "storage_size": 2066080,
@@ -994,6 +1000,7 @@ GET /projects/:id
   "autoclose_referenced_issues": true,
   "suggestion_commit_message": null,
   "merge_commit_template": null,
+  "squash_commit_template": null,
   "marked_for_deletion_at": "2020-04-03", // Deprecated and will be removed in API v5 in favor of marked_for_deletion_on
   "marked_for_deletion_on": "2020-04-03",
   "compliance_frameworks": [ "sox" ],
@@ -1307,6 +1314,7 @@ POST /projects/user/:user_id
 | `jobs_enabled`                                              | boolean | **{dotted-circle}** No | _(Deprecated)_ Enable jobs for this project. Use `builds_access_level` instead. |
 | `lfs_enabled`                                               | boolean | **{dotted-circle}** No | Enable LFS. |
 | `merge_commit_template`                                     | string  | **{dotted-circle}** No | [Template](../user/project/merge_requests/commit_templates.md) used to create merge commit message in merge requests. _([Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/20263) in GitLab 14.5.)_ |
+| `squash_commit_template`                                    | string  | **{dotted-circle}** No | [Template](../user/project/merge_requests/commit_templates.md#squash-commit-message-template) used to create squash commit message in merge requests. _([Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/345275) in GitLab 14.6.)_ |
 | `merge_method`                                              | string  | **{dotted-circle}** No | Set the [merge method](#project-merge-method) used. |
 | `merge_requests_access_level`                               | string  | **{dotted-circle}** No | One of `disabled`, `private`, or `enabled`. |
 | `merge_requests_enabled`                                    | boolean | **{dotted-circle}** No | _(Deprecated)_ Enable merge requests for this project. Use `merge_requests_access_level` instead. |

doc/user/project/merge_requests/commit_templates.md

@@ -31,7 +31,7 @@ This commit message can be customized to follow any guidelines you might have.
 To do so, expand the **Merge requests** tab within your project's **General**
 settings and change the **Merge commit message template** text:
 
-![Custom commit message for applied suggestions](img/merge_commit_message_template_v14_5.png)
+![Custom commit message for merge commit](img/merge_commit_message_template_v14_5.png)
 
 You can use static text and following variables:
 
@@ -49,3 +49,18 @@ Empty variables that are the only word in a line will be removed along with all
 
 Merge commit template field has a limit of 500 characters. This limit only applies to the template
 itself.
+
+## Squash commit message template
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/345275) in GitLab 14.6.
+
+As a project maintainer, you're able to configure squash commit message template. It will be used during merge with
+squash to create squash commit message. It uses the same syntax and variables as merge commit message template.
+
+![Custom commit message for squash commit](img/squash_commit_message_template_v14_6.png)
+
+Default squash commit message can be recreated using following template:
+
+```plaintext
+%{title}
+```

doc/user/project/merge_requests/squash_and_merge.md

@@ -28,9 +28,9 @@ NOTE:
 The squashed commit in this example is followed by a merge commit, because the merge method for this repository uses a merge commit. You can disable merge commits in
 **Project Settings > General > Merge requests > Merge method > Fast-forward merge**.
 
-The squashed commit's default commit message is taken from the merge request title.
+The squashed commit's default commit message is taken from the merge request title. It can be changed using [squash commit message template](commit_templates.md#squash-commit-message-template).
 
-It can be customized before merging a merge request.
+It can also be customized before merging a merge request.
 
 ![A squash commit message editor](img/squash_mr_message.png)
 

doc/user/project/settings/index.md

@@ -315,7 +315,7 @@ Set up your project's merge request settings:
 - Enable [require an associated issue from Jira](../../../integration/jira/issues.md#require-associated-jira-issue-for-merge-requests-to-be-merged).
 - Enable [`delete source branch after merge` option by default](../merge_requests/getting_started.md#deleting-the-source-branch).
 - Configure [suggested changes commit messages](../merge_requests/reviews/suggestions.md#configure-the-commit-message-for-applied-suggestions).
-- Configure [merge commit message template](../merge_requests/commit_templates.md).
+- Configure [merge and squash commit message templates](../merge_requests/commit_templates.md).
 - Configure [the default target project](../merge_requests/creating_merge_requests.md#set-the-default-target-project) for merge requests coming from forks.
 
 ### Service Desk

ee/app/views/projects/_merge_request_settings.html.haml

@@ -15,6 +15,8 @@
 
 = render_ce 'projects/merge_request_merge_commit_template', project: @project, form: form
 
+= render_ce 'projects/merge_request_squash_commit_template', project: @project, form: form
+
 - if @project.forked?
   = render_ce 'projects/merge_request_target_project_settings', project: @project, form: form
 

lib/api/entities/project.rb

@@ -115,6 +115,7 @@ module API
       expose :squash_option
       expose :suggestion_commit_message
       expose :merge_commit_template
+      expose :squash_commit_template
       expose :statistics, using: 'API::Entities::ProjectStatistics', if: -> (project, options) {
         options[:statistics] && Ability.allowed?(options[:current_user], :read_statistics, project)
       }

lib/api/helpers/projects_helpers.rb

@@ -62,6 +62,7 @@ module API
         optional :merge_method, type: String, values: %w(ff rebase_merge merge), desc: 'The merge method used when merging merge requests'
         optional :suggestion_commit_message, type: String, desc: 'The commit message used to apply merge request suggestions'
         optional :merge_commit_template, type: String, desc: 'Template used to create merge commit message'
+        optional :squash_commit_template, type: String, desc: 'Template used to create squash commit message'
         optional :initialize_with_readme, type: Boolean, desc: "Initialize a project with a README.md"
         optional :ci_default_git_depth, type: Integer, desc: 'Default number of revisions for shallow cloning'
         optional :auto_devops_enabled, type: Boolean, desc: 'Flag indication if Auto DevOps is enabled'
@@ -162,6 +163,7 @@ module API
           :avatar,
           :suggestion_commit_message,
           :merge_commit_template,
+          :squash_commit_template,
           :repository_storage,
           :compliance_framework_setting,
           :packages_enabled,

lib/gitlab/merge_requests/merge_commit_message.rb → lib/gitlab/merge_requests/commit_message_generator.rb

 # frozen_string_literal: true
 module Gitlab
   module MergeRequests
-    class MergeCommitMessage
+    class CommitMessageGenerator
       def initialize(merge_request:)
         @merge_request = merge_request
       end
 
-      def message
+      def merge_message
         return unless @merge_request.target_project.merge_commit_template.present?
 
-        message = @merge_request.target_project.merge_commit_template
-        message = message.delete("\r")
+        replace_placeholders(@merge_request.target_project.merge_commit_template)
+      end
 
-        # Remove placeholders that correspond to empty values and are the last word in the line
-        # along with all whitespace characters preceding them.
-        # This allows us to recreate previous default merge commit message behaviour - we skipped new line character
-        # before empty description and before closed issues when none were present.
-        PLACEHOLDERS.each do |key, value|
-          unless value.call(merge_request).present?
-            message = message.gsub(BLANK_PLACEHOLDERS_REGEXES[key], '')
-          end
-        end
+      def squash_message
+        return unless @merge_request.target_project.squash_commit_template.present?
 
-        Gitlab::StringPlaceholderReplacer
-          .replace_string_placeholders(message, PLACEHOLDERS_REGEX) do |key|
-          PLACEHOLDERS[key].call(merge_request)
-        end
+        replace_placeholders(@merge_request.target_project.squash_commit_template)
       end
 
       private
@@ -55,6 +45,26 @@ module Gitlab
       BLANK_PLACEHOLDERS_REGEXES = (PLACEHOLDERS.map do |key, value|
         [key, Regexp.new("[\n\r]+%{#{Regexp.escape(key)}}$")]
       end).to_h.freeze
+
+      def replace_placeholders(message)
+        # convert CRLF to LF
+        message = message.delete("\r")
+
+        # Remove placeholders that correspond to empty values and are the last word in the line
+        # along with all whitespace characters preceding them.
+        # This allows us to recreate previous default merge commit message behaviour - we skipped new line character
+        # before empty description and before closed issues when none were present.
+        PLACEHOLDERS.each do |key, value|
+          unless value.call(merge_request).present?
+            message = message.gsub(BLANK_PLACEHOLDERS_REGEXES[key], '')
+          end
+        end
+
+        Gitlab::StringPlaceholderReplacer
+          .replace_string_placeholders(message, PLACEHOLDERS_REGEX) do |key|
+          PLACEHOLDERS[key].call(merge_request)
+        end
+      end
     end
   end
 end

locale/gitlab.pot

@@ -27449,6 +27449,9 @@ msgstr ""
 msgid "ProjectSettings|Snippets"
 msgstr ""
 
+msgid "ProjectSettings|Squash commit message template"
+msgstr ""
+
 msgid "ProjectSettings|Squash commits when merging"
 msgstr ""
 
@@ -27473,6 +27476,9 @@ msgstr ""
 msgid "ProjectSettings|The commit message used when merging, if the merge method creates a merge commit. %{link_start}Learn more about syntax and variables.%{link_end}"
 msgstr ""
 
+msgid "ProjectSettings|The commit message used when squashing commits. %{link_start}Learn more about syntax and variables.%{link_end}"
+msgstr ""
+
 msgid "ProjectSettings|The default target project for merge requests created in this fork project."
 msgstr ""
 
@@ -41711,9 +41717,15 @@ msgstr ""
 msgid "mrWidget|To approve this merge request, please enter your password. This project requires all approvals to be authenticated."
 msgstr ""
 
+msgid "mrWidget|To change these default messages, edit the templates for both the merge and squash commit messages. %{linkStart}Learn more.%{linkEnd}"
+msgstr ""
+
 msgid "mrWidget|To change this default message, edit the template for merge commit messages. %{linkStart}Learn more.%{linkEnd}"
 msgstr ""
 
+msgid "mrWidget|To change this default message, edit the template for squash commit messages. %{linkStart}Learn more.%{linkEnd}"
+msgstr ""
+
 msgid "mrWidget|To merge, a Jira issue key must be mentioned in the title or description."
 msgstr ""
 

spec/features/merge_request/user_customizes_merge_commit_message_spec.rb

@@ -7,19 +7,26 @@ RSpec.describe 'Merge request < User customizes merge commit message', :js do
   let(:user) { project.creator }
   let(:issue_1) { create(:issue, project: project)}
   let(:issue_2) { create(:issue, project: project)}
+  let(:source_branch) { 'csv' }
+  let(:target_branch) { 'master' }
+  let(:squash) { false }
   let(:merge_request) do
     create(
       :merge_request,
-      :simple,
       source_project: project,
-      description: "Description\n\nclosing #{issue_1.to_reference}, #{issue_2.to_reference}"
+      target_project: project,
+      source_branch: source_branch,
+      target_branch: target_branch,
+      description: "Description\n\nclosing #{issue_1.to_reference}, #{issue_2.to_reference}",
+      squash: squash
     )
   end
 
-  let(:textbox) { page.find(:css, '#merge-message-edit', visible: false) }
-  let(:default_message) do
+  let(:merge_textbox) { page.find(:css, '#merge-message-edit', visible: false) }
+  let(:squash_textbox) { page.find(:css, '#squash-message-edit', visible: false) }
+  let(:default_merge_commit_message) do
     [
-      "Merge branch 'feature' into 'master'",
+      "Merge branch '#{source_branch}' into '#{target_branch}'",
       merge_request.title,
       "Closes #{issue_1.to_reference} and #{issue_2.to_reference}",
       "See merge request #{merge_request.to_reference(full: true)}"
@@ -35,8 +42,8 @@ RSpec.describe 'Merge request < User customizes merge commit message', :js do
   it 'has commit message without description' do
     expect(page).not_to have_selector('#merge-message-edit')
     first('.js-mr-widget-commits-count').click
-    expect(textbox).to be_visible
-    expect(textbox.value).to eq(default_message)
+    expect(merge_textbox).to be_visible
+    expect(merge_textbox.value).to eq(default_merge_commit_message)
   end
 
   context 'when target project has merge commit template set' do
@@ -45,8 +52,34 @@ RSpec.describe 'Merge request < User customizes merge commit message', :js do
     it 'uses merge commit template' do
       expect(page).not_to have_selector('#merge-message-edit')
       first('.js-mr-widget-commits-count').click
-      expect(textbox).to be_visible
-      expect(textbox.value).to eq(merge_request.title)
+      expect(merge_textbox).to be_visible
+      expect(merge_textbox.value).to eq(merge_request.title)
+    end
+  end
+
+  context 'when squash is performed' do
+    let(:squash) { true }
+
+    it 'has default message with merge request title' do
+      expect(page).not_to have_selector('#squash-message-edit')
+      first('.js-mr-widget-commits-count').click
+      expect(squash_textbox).to be_visible
+      expect(merge_textbox).to be_visible
+      expect(squash_textbox.value).to eq(merge_request.title)
+      expect(merge_textbox.value).to eq(default_merge_commit_message)
+    end
+
+    context 'when target project has squash commit template set' do
+      let(:project) { create(:project, :public, :repository, squash_commit_template: '%{description}') }
+
+      it 'uses squash commit template' do
+        expect(page).not_to have_selector('#squash-message-edit')
+        first('.js-mr-widget-commits-count').click
+        expect(squash_textbox).to be_visible
+        expect(merge_textbox).to be_visible
+        expect(squash_textbox.value).to eq(merge_request.description)
+        expect(merge_textbox.value).to eq(default_merge_commit_message)
+      end
     end
   end
 end

spec/frontend/vue_mr_widget/components/states/commit_edit_spec.js

@@ -3,7 +3,6 @@ import CommitEdit from '~/vue_merge_request_widget/components/states/commit_edit
 
 const testCommitMessage = 'Test commit message';
 const testLabel = 'Test label';
-const testTextMuted = 'Test text muted';
 const testInputId = 'test-input-id';
 
 describe('Commits edit component', () => {
@@ -64,7 +63,6 @@ describe('Commits edit component', () => {
     beforeEach(() => {
       createComponent({
         header: `<div class="test-header">${testCommitMessage}</div>`,
-        'text-muted': `<p class="test-text-muted">${testTextMuted}</p>`,
       });
     });
 
@@ -74,12 +72,5 @@ describe('Commits edit component', () => {
       expect(headerSlotElement.exists()).toBe(true);
       expect(headerSlotElement.text()).toBe(testCommitMessage);
     });
-
-    it('renders text-muted slot correctly', () => {
-      const textMutedElement = wrapper.find('.test-text-muted');
-
-      expect(textMutedElement.exists()).toBe(true);
-      expect(textMutedElement.text()).toBe(testTextMuted);
-    });
   });
 });

spec/frontend/vue_mr_widget/components/states/mr_widget_ready_to_merge_spec.js

 import { shallowMount } from '@vue/test-utils';
 import Vue from 'vue';
+import { GlSprintf } from '@gitlab/ui';
 import simplePoll from '~/lib/utils/simple_poll';
 import CommitEdit from '~/vue_merge_request_widget/components/states/commit_edit.vue';
 import CommitMessageDropdown from '~/vue_merge_request_widget/components/states/commit_message_dropdown.vue';
@@ -487,6 +488,7 @@ describe('ReadyToMerge', () => {
     const findCommitEditElements = () => wrapper.findAll(CommitEdit);
     const findCommitDropdownElement = () => wrapper.find(CommitMessageDropdown);
     const findFirstCommitEditLabel = () => findCommitEditElements().at(0).props('label');
+    const findTipLink = () => wrapper.find(GlSprintf);
 
     describe('squash checkbox', () => {
       it('should be rendered when squash before merge is enabled and there is more than 1 commit', () => {
@@ -751,6 +753,12 @@ describe('ReadyToMerge', () => {
         expect(findCommitDropdownElement().exists()).toBeTruthy();
       });
     });
+
+    it('renders a tip including a link to docs on templates', () => {
+      createComponent();
+
+      expect(findTipLink().exists()).toBe(true);
+    });
   });
 
   describe('Merge request project settings', () => {

spec/graphql/types/project_type_spec.rb

@@ -34,7 +34,7 @@ RSpec.describe GitlabSchema.types['Project'] do
       container_repositories container_repositories_count
       pipeline_analytics squash_read_only sast_ci_configuration
       cluster_agent cluster_agents agent_configurations
-      ci_template timelogs merge_commit_template
+      ci_template timelogs merge_commit_template squash_commit_template
     ]
 
     expect(described_class).to include_graphql_fields(*expected_fields)

spec/lib/gitlab/import_export/safe_model_attributes.yml

@@ -563,6 +563,7 @@ Project:
 - autoclose_referenced_issues
 - suggestion_commit_message
 - merge_commit_template
+- squash_commit_template
 ProjectTracingSetting:
 - external_url
 Author:

spec/lib/gitlab/merge_requests/commit_message_generator_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::MergeRequests::CommitMessageGenerator do
+  let(:merge_commit_template) { nil }
+  let(:squash_commit_template) { nil }
+  let(:project) do
+    create(
+      :project,
+      :public,
+      :repository,
+      merge_commit_template: merge_commit_template,
+      squash_commit_template: squash_commit_template
+    )
+  end
+
+  let(:user) { project.creator }
+  let(:merge_request_description) { "Merge Request Description\nNext line" }
+  let(:merge_request_title) { 'Bugfix' }
+  let(:merge_request) do
+    create(
+      :merge_request,
+      :simple,
+      source_project: project,
+      target_project: project,
+      author: user,
+      description: merge_request_description,
+      title: merge_request_title
+    )
+  end
+
+  subject { described_class.new(merge_request: merge_request) }
+
+  shared_examples_for 'commit message with template' do |message_template_name|
+    it 'returns nil when template is not set in target project' do
+      expect(result_message).to be_nil
+    end
+
+    context 'when project has custom commit template' do
+      let(message_template_name) { <<~MSG.rstrip }
+        %{title}
+
+        See merge request %{reference}
+      MSG
+
+      it 'uses custom template' do
+        expect(result_message).to eq <<~MSG.rstrip
+          Bugfix
+
+          See merge request #{merge_request.to_reference(full: true)}
+        MSG
+      end
+    end
+
+    context 'when project has commit template with closed issues' do
+      let(message_template_name) { <<~MSG.rstrip }
+        Merge branch '%{source_branch}' into '%{target_branch}'
+
+        %{title}
+
+        %{issues}
+
+        See merge request %{reference}
+      MSG
+
+      it 'omits issues and new lines when no issues are mentioned in description' do
+        expect(result_message).to eq <<~MSG.rstrip
+          Merge branch 'feature' into 'master'
+
+          Bugfix
+
+          See merge request #{merge_request.to_reference(full: true)}
+        MSG
+      end
+
+      context 'when MR closes issues' do
+        let(:issue_1) { create(:issue, project: project) }
+        let(:issue_2) { create(:issue, project: project) }
+        let(:merge_request_description) { "Description\n\nclosing #{issue_1.to_reference}, #{issue_2.to_reference}" }
+
+        it 'includes them and keeps new line characters' do
+          expect(result_message).to eq <<~MSG.rstrip
+            Merge branch 'feature' into 'master'
+
+            Bugfix
+
+            Closes #{issue_1.to_reference} and #{issue_2.to_reference}
+
+            See merge request #{merge_request.to_reference(full: true)}
+          MSG
+        end
+      end
+    end
+
+    context 'when project has commit template with description' do
+      let(message_template_name) { <<~MSG.rstrip }
+        Merge branch '%{source_branch}' into '%{target_branch}'
+
+        %{title}
+
+        %{description}
+
+        See merge request %{reference}
+      MSG
+
+      it 'uses template' do
+        expect(result_message).to eq <<~MSG.rstrip
+          Merge branch 'feature' into 'master'
+
+          Bugfix
+
+          Merge Request Description
+          Next line
+
+          See merge request #{merge_request.to_reference(full: true)}
+        MSG
+      end
+
+      context 'when description is empty string' do
+        let(:merge_request_description) { '' }
+
+        it 'skips description placeholder and removes new line characters before it' do
+          expect(result_message).to eq <<~MSG.rstrip
+            Merge branch 'feature' into 'master'
+
+            Bugfix
+
+            See merge request #{merge_request.to_reference(full: true)}
+          MSG
+        end
+      end
+
+      context 'when description is nil' do
+        let(:merge_request_description) { nil }
+
+        it 'skips description placeholder and removes new line characters before it' do
+          expect(result_message).to eq <<~MSG.rstrip
+            Merge branch 'feature' into 'master'
+
+            Bugfix
+
+            See merge request #{merge_request.to_reference(full: true)}
+          MSG
+        end
+      end
+
+      context 'when description is blank string' do
+        let(:merge_request_description) { "\n\r  \n" }
+
+        it 'skips description placeholder and removes new line characters before it' do
+          expect(result_message).to eq <<~MSG.rstrip
+            Merge branch 'feature' into 'master'
+
+            Bugfix
+
+            See merge request #{merge_request.to_reference(full: true)}
+          MSG
+        end
+      end
+    end
+
+    context 'when custom commit template contains placeholder in the middle or beginning of the line' do
+      let(message_template_name) { <<~MSG.rstrip }
+        Merge branch '%{source_branch}' into '%{target_branch}'
+
+        %{description} %{title}
+
+        See merge request %{reference}
+      MSG
+
+      it 'uses custom template' do
+        expect(result_message).to eq <<~MSG.rstrip
+          Merge branch 'feature' into 'master'
+
+          Merge Request Description
+          Next line Bugfix
+
+          See merge request #{merge_request.to_reference(full: true)}
+        MSG
+      end
+
+      context 'when description is empty string' do
+        let(:merge_request_description) { '' }
+
+        it 'does not remove new line characters before empty placeholder' do
+          expect(result_message).to eq <<~MSG.rstrip
+            Merge branch 'feature' into 'master'
+
+             Bugfix
+
+            See merge request #{merge_request.to_reference(full: true)}
+          MSG
+        end
+      end
+    end
+
+    context 'when project has template with CRLF newlines' do
+      let(message_template_name) do
+        "Merge branch '%{source_branch}' into '%{target_branch}'\r\n\r\n%{title}\r\n\r\n%{description}\r\n\r\nSee merge request %{reference}"
+      end
+
+      it 'converts it to LF newlines' do
+        expect(result_message).to eq <<~MSG.rstrip
+          Merge branch 'feature' into 'master'
+
+          Bugfix
+
+          Merge Request Description
+          Next line
+
+          See merge request #{merge_request.to_reference(full: true)}
+        MSG
+      end
+
+      context 'when description is empty string' do
+        let(:merge_request_description) { '' }
+
+        it 'skips description placeholder and removes new line characters before it' do
+          expect(result_message).to eq <<~MSG.rstrip
+            Merge branch 'feature' into 'master'
+
+            Bugfix
+
+            See merge request #{merge_request.to_reference(full: true)}
+          MSG
+        end
+      end
+    end
+  end
+
+  describe '#merge_message' do
+    let(:result_message) { subject.merge_message }
+
+    it_behaves_like 'commit message with template', :merge_commit_template
+  end
+
+  describe '#squash_message' do
+    let(:result_message) { subject.squash_message }
+
+    it_behaves_like 'commit message with template', :squash_commit_template
+  end
+end

spec/lib/gitlab/merge_requests/merge_commit_message_spec.rb

-# frozen_string_literal: true
-
-require 'spec_helper'
-
-RSpec.describe Gitlab::MergeRequests::MergeCommitMessage do
-  let(:merge_commit_template) { nil }
-  let(:project) { create(:project, :public, :repository, merge_commit_template: merge_commit_template) }
-  let(:user) { project.creator }
-  let(:merge_request_description) { "Merge Request Description\nNext line" }
-  let(:merge_request_title) { 'Bugfix' }
-  let(:merge_request) do
-    create(
-      :merge_request,
-      :simple,
-      source_project: project,
-      target_project: project,
-      author: user,
-      description: merge_request_description,
-      title: merge_request_title
-    )
-  end
-
-  subject { described_class.new(merge_request: merge_request) }
-
-  it 'returns nil when template is not set in target project' do
-    expect(subject.message).to be_nil
-  end
-
-  context 'when project has custom merge commit template' do
-    let(:merge_commit_template) { <<~MSG.rstrip }
-      %{title}
-
-      See merge request %{reference}
-    MSG
-
-    it 'uses custom template' do
-      expect(subject.message).to eq <<~MSG.rstrip
-        Bugfix
-
-        See merge request #{merge_request.to_reference(full: true)}
-      MSG
-    end
-  end
-
-  context 'when project has merge commit template with closed issues' do
-    let(:merge_commit_template) { <<~MSG.rstrip }
-      Merge branch '%{source_branch}' into '%{target_branch}'
-
-      %{title}
-
-      %{issues}
-
-      See merge request %{reference}
-    MSG
-
-    it 'omits issues and new lines when no issues are mentioned in description' do
-      expect(subject.message).to eq <<~MSG.rstrip
-        Merge branch 'feature' into 'master'
-
-        Bugfix
-
-        See merge request #{merge_request.to_reference(full: true)}
-      MSG
-    end
-
-    context 'when MR closes issues' do
-      let(:issue_1) { create(:issue, project: project) }
-      let(:issue_2) { create(:issue, project: project) }
-      let(:merge_request_description) { "Description\n\nclosing #{issue_1.to_reference}, #{issue_2.to_reference}" }
-
-      it 'includes them and keeps new line characters' do
-        expect(subject.message).to eq <<~MSG.rstrip
-          Merge branch 'feature' into 'master'
-
-          Bugfix
-
-          Closes #{issue_1.to_reference} and #{issue_2.to_reference}
-
-          See merge request #{merge_request.to_reference(full: true)}
-        MSG
-      end
-    end
-  end
-
-  context 'when project has merge commit template with description' do
-    let(:merge_commit_template) { <<~MSG.rstrip }
-      Merge branch '%{source_branch}' into '%{target_branch}'
-
-      %{title}
-
-      %{description}
-
-      See merge request %{reference}
-    MSG
-
-    it 'uses template' do
-      expect(subject.message).to eq <<~MSG.rstrip
-        Merge branch 'feature' into 'master'
-
-        Bugfix
-
-        Merge Request Description
-        Next line
-
-        See merge request #{merge_request.to_reference(full: true)}
-      MSG
-    end
-
-    context 'when description is empty string' do
-      let(:merge_request_description) { '' }
-
-      it 'skips description placeholder and removes new line characters before it' do
-        expect(subject.message).to eq <<~MSG.rstrip
-          Merge branch 'feature' into 'master'
-
-          Bugfix
-
-          See merge request #{merge_request.to_reference(full: true)}
-        MSG
-      end
-    end
-
-    context 'when description is nil' do
-      let(:merge_request_description) { nil }
-
-      it 'skips description placeholder and removes new line characters before it' do
-        expect(subject.message).to eq <<~MSG.rstrip
-          Merge branch 'feature' into 'master'
-
-          Bugfix
-
-          See merge request #{merge_request.to_reference(full: true)}
-        MSG
-      end
-    end
-
-    context 'when description is blank string' do
-      let(:merge_request_description) { "\n\r  \n" }
-
-      it 'skips description placeholder and removes new line characters before it' do
-        expect(subject.message).to eq <<~MSG.rstrip
-          Merge branch 'feature' into 'master'
-
-          Bugfix
-
-          See merge request #{merge_request.to_reference(full: true)}
-        MSG
-      end
-    end
-  end
-
-  context 'when custom merge commit template contains placeholder in the middle or beginning of the line' do
-    let(:merge_commit_template) { <<~MSG.rstrip }
-      Merge branch '%{source_branch}' into '%{target_branch}'
-
-      %{description} %{title}
-
-      See merge request %{reference}
-    MSG
-
-    it 'uses custom template' do
-      expect(subject.message).to eq <<~MSG.rstrip
-        Merge branch 'feature' into 'master'
-
-        Merge Request Description
-        Next line Bugfix
-
-        See merge request #{merge_request.to_reference(full: true)}
-      MSG
-    end
-
-    context 'when description is empty string' do
-      let(:merge_request_description) { '' }
-
-      it 'does not remove new line characters before empty placeholder' do
-        expect(subject.message).to eq <<~MSG.rstrip
-          Merge branch 'feature' into 'master'
-
-           Bugfix
-
-          See merge request #{merge_request.to_reference(full: true)}
-        MSG
-      end
-    end
-  end
-
-  context 'when project has template with CRLF newlines' do
-    let(:merge_commit_template) do
-      "Merge branch '%{source_branch}' into '%{target_branch}'\r\n\r\n%{title}\r\n\r\n%{description}\r\n\r\nSee merge request %{reference}"
-    end
-
-    it 'converts it to LF newlines' do
-      expect(subject.message).to eq <<~MSG.rstrip
-        Merge branch 'feature' into 'master'
-
-        Bugfix
-
-        Merge Request Description
-        Next line
-
-        See merge request #{merge_request.to_reference(full: true)}
-      MSG
-    end
-
-    context 'when description is empty string' do
-      let(:merge_request_description) { '' }
-
-      it 'skips description placeholder and removes new line characters before it' do
-        expect(subject.message).to eq <<~MSG.rstrip
-          Merge branch 'feature' into 'master'
-
-          Bugfix
-
-          See merge request #{merge_request.to_reference(full: true)}
-        MSG
-      end
-    end
-  end
-end

spec/models/merge_request_spec.rb

@@ -178,6 +178,13 @@ RSpec.describe MergeRequest, factory_default: :keep do
     it 'returns the merge request title' do
       expect(subject.default_squash_commit_message).to eq(subject.title)
     end
+
+    it 'uses template from target project' do
+      subject.target_project.squash_commit_template = 'Squashed branch %{source_branch} into %{target_branch}'
+
+      expect(subject.default_squash_commit_message)
+        .to eq('Squashed branch master into feature')
+    end
   end
 
   describe 'modules' do

spec/views/projects/edit.html.haml_spec.rb

@@ -92,6 +92,22 @@ RSpec.describe 'projects/edit' do
     end
   end
 
+  context 'squash template' do
+    it 'displays a placeholder if none is set' do
+      render
+
+      expect(rendered).to have_field('project[squash_commit_template]', placeholder: '%{title}')
+    end
+
+    it 'displays the user entered value' do
+      project.update!(squash_commit_template: '%{first_multiline_commit}')
+
+      render
+
+      expect(rendered).to have_field('project[squash_commit_template]', with: '%{first_multiline_commit}')
+    end
+  end
+
   context 'forking' do
     before do
       assign(:project, project)