1 files changed, 49 insertions, 0 deletions
diff --git a/app/assets/javascripts/diffs/utils/interoperability.js b/app/assets/javascripts/diffs/utils/interoperability.js
new file mode 100644
index 00000000000..a52e8fd25f5
--- /dev/null
+++ b/app/assets/javascripts/diffs/utils/interoperability.js
@@ -0,0 +1,49 @@
+const OLD = 'old';
+const NEW = 'new';
+const ATTR_PREFIX = 'data-interop-';
+
+export const ATTR_TYPE = `${ATTR_PREFIX}type`;
+export const ATTR_LINE = `${ATTR_PREFIX}line`;
+export const ATTR_NEW_LINE = `${ATTR_PREFIX}new-line`;
+export const ATTR_OLD_LINE = `${ATTR_PREFIX}old-line`;
+
+export const getInteropInlineAttributes = (line) => {
+  if (!line) {
+    return null;
+  }
+
+  const interopType = line.type?.startsWith(OLD) ? OLD : NEW;
+
+  const interopLine = interopType === OLD ? line.old_line : line.new_line;
+
+  return {
+    [ATTR_TYPE]: interopType,
+    [ATTR_LINE]: interopLine,
+    [ATTR_NEW_LINE]: line.new_line,
+    [ATTR_OLD_LINE]: line.old_line,
+  };
+};
+
+export const getInteropOldSideAttributes = (line) => {
+  if (!line) {
+    return null;
+  }
+
+  return {
+    [ATTR_TYPE]: OLD,
+    [ATTR_LINE]: line.old_line,
+    [ATTR_OLD_LINE]: line.old_line,
+  };
+};
+
+export const getInteropNewSideAttributes = (line) => {
+  if (!line) {
+    return null;
+  }
+
+  return {
+    [ATTR_TYPE]: NEW,
+    [ATTR_LINE]: line.new_line,
+    [ATTR_NEW_LINE]: line.new_line,
+  };
+};