1 files changed, 22 insertions, 0 deletions
diff --git a/app/assets/javascripts/diffs/utils/preferences.js b/app/assets/javascripts/diffs/utils/preferences.js
new file mode 100644
index 00000000000..e440de3350a
--- /dev/null
+++ b/app/assets/javascripts/diffs/utils/preferences.js
@@ -0,0 +1,22 @@
+import Cookies from 'js-cookie';
+import { getParameterValues } from '~/lib/utils/url_utility';
+
+import { DIFF_FILE_BY_FILE_COOKIE_NAME, DIFF_VIEW_FILE_BY_FILE } from '../constants';
+
+export function fileByFile(pref = false) {
+  const search = getParameterValues(DIFF_FILE_BY_FILE_COOKIE_NAME)?.[0];
+  const cookie = Cookies.get(DIFF_FILE_BY_FILE_COOKIE_NAME);
+  let viewFileByFile = pref;
+
+  // use the cookie first, if it exists
+  if (cookie) {
+    viewFileByFile = cookie === DIFF_VIEW_FILE_BY_FILE;
+  }
+
+  // the search parameter of the URL should override, if it exists
+  if (search) {
+    viewFileByFile = search === DIFF_VIEW_FILE_BY_FILE;
+  }
+
+  return viewFileByFile;
+}