2 files changed, 20 insertions, 0 deletions
diff --git a/app/assets/javascripts/pages/projects/edit/index.js b/app/assets/javascripts/pages/projects/edit/index.js
index 92ed6a652d7..ecf38d87aac 100644
--- a/app/assets/javascripts/pages/projects/edit/index.js
+++ b/app/assets/javascripts/pages/projects/edit/index.js
@@ -7,6 +7,7 @@ import dirtySubmitFactory from '~/dirty_submit/dirty_submit_factory';
 import initAvatarPicker from '~/avatar_picker';
 import initProjectLoadingSpinner from '../shared/save_project_loader';
 import initProjectPermissionsSettings from '../shared/permissions';
+import initMergeOptionsCheckboxSync from './init_merge_options_checkbox_sync';
 
 document.addEventListener('DOMContentLoaded', () => {
   initAvatarPicker();
@@ -17,6 +18,7 @@ document.addEventListener('DOMContentLoaded', () => {
   initProjectLoadingSpinner();
   initProjectPermissionsSettings();
   setupProjectEdit();
+  initMergeOptionsCheckboxSync();
 
   dirtySubmitFactory(
     document.querySelectorAll(
diff --git a/app/assets/javascripts/pages/projects/edit/init_merge_options_checkbox_sync.js b/app/assets/javascripts/pages/projects/edit/init_merge_options_checkbox_sync.js
new file mode 100644
index 00000000000..19fbf10bbf6
--- /dev/null
+++ b/app/assets/javascripts/pages/projects/edit/init_merge_options_checkbox_sync.js
@@ -0,0 +1,18 @@
+export default () => {
+  const mergePipelinesCheckbox = document.querySelector('.js-merge-options-merge-pipelines');
+  const mergeTrainsCheckbox = document.querySelector('.js-merge-options-merge-trains');
+
+  if (mergePipelinesCheckbox && mergeTrainsCheckbox) {
+    mergePipelinesCheckbox.addEventListener('change', event => {
+      if (!event.target.checked && mergeTrainsCheckbox.checked) {
+        mergeTrainsCheckbox.click();
+      }
+    });
+
+    mergeTrainsCheckbox.addEventListener('change', event => {
+      if (event.target.checked && !mergePipelinesCheckbox.checked) {
+        mergePipelinesCheckbox.click();
+      }
+    });
+  }
+};