1 files changed, 66 insertions, 0 deletions
diff --git a/app/assets/javascripts/snippets/utils/blob.js b/app/assets/javascripts/snippets/utils/blob.js
new file mode 100644
index 00000000000..fd5ff9a3d2e
--- /dev/null
+++ b/app/assets/javascripts/snippets/utils/blob.js
@@ -0,0 +1,66 @@
+import { uniqueId } from 'lodash';
+import {
+  SNIPPET_BLOB_ACTION_CREATE,
+  SNIPPET_BLOB_ACTION_UPDATE,
+  SNIPPET_BLOB_ACTION_MOVE,
+  SNIPPET_BLOB_ACTION_DELETE,
+} from '../constants';
+
+const createLocalId = () => uniqueId('blob_local_');
+
+export const decorateBlob = blob => ({
+  ...blob,
+  id: createLocalId(),
+  isLoaded: false,
+  content: '',
+});
+
+export const createBlob = () => ({
+  id: createLocalId(),
+  content: '',
+  path: '',
+  isLoaded: true,
+});
+
+const diff = ({ content, path }, origBlob) => {
+  if (!origBlob) {
+    return {
+      action: SNIPPET_BLOB_ACTION_CREATE,
+      previousPath: path,
+      content,
+      filePath: path,
+    };
+  } else if (origBlob.path !== path || origBlob.content !== content) {
+    return {
+      action: origBlob.path === path ? SNIPPET_BLOB_ACTION_UPDATE : SNIPPET_BLOB_ACTION_MOVE,
+      previousPath: origBlob.path,
+      content,
+      filePath: path,
+    };
+  }
+
+  return null;
+};
+
+/**
+ * This function returns an array of diff actions (to be sent to the BE) based on the current vs. original blobs
+ *
+ * @param {Object} blobs
+ * @param {Object} origBlobs
+ */
+export const diffAll = (blobs, origBlobs) => {
+  const deletedEntries = Object.values(origBlobs)
+    .filter(x => !blobs[x.id])
+    .map(({ path, content }) => ({
+      action: SNIPPET_BLOB_ACTION_DELETE,
+      previousPath: path,
+      filePath: path,
+      content,
+    }));
+
+  const newEntries = Object.values(blobs)
+    .map(blob => diff(blob, origBlobs[blob.id]))
+    .filter(x => x);
+
+  return [...deletedEntries, ...newEntries];
+};