feat: 🎸 added getFlattenedTreePaths selector

added a selector that crawls a tree, flattens it for visible nodes and
creates an array with the path to reach the node on the original tree

src/selectors/__tests__/__snapshots__/getFlattenedTree.test.js.snap

@@ -140,3 +140,35 @@ Array [
   },
 ]
 `;
+
+exports[`getFlattenedTreePaths, should match snapshot 1`] = `
+Array [
+  Array [
+    0,
+  ],
+  Array [
+    0,
+    2,
+  ],
+  Array [
+    0,
+    2,
+    3,
+  ],
+  Array [
+    0,
+    2,
+    4,
+  ],
+  Array [
+    0,
+    5,
+  ],
+  Array [
+    1,
+  ],
+  Array [
+    "z",
+  ],
+]
+`;

src/selectors/__tests__/getFlattenedTree.test.js

@@ -1,8 +1,12 @@
-import {getFlattenedTree} from '../getFlattenedTree';
+import {getFlattenedTree, getFlattenedTreePaths} from '../getFlattenedTree';
 import {Nodes} from '../../../testData/sampleTree';
 
 describe('getFlattenedTree', () => {
   it('should match snapshot', () => {
     expect(getFlattenedTree(Nodes)).toMatchSnapshot();
   });
 });
+
+test('getFlattenedTreePaths, should match snapshot', () => {
+  expect(getFlattenedTreePaths(Nodes)).toMatchSnapshot();
+});

src/selectors/getFlattenedTree.js

@@ -12,3 +12,20 @@ export const getFlattenedTree = (nodes, parents = []) =>
 
     return [...flattenedTree, nodeWithHelpers, ...getFlattenedTree(node.children, [...parents, node.id])];
   }, []);
+
+export const getFlattenedTreePaths = (nodes, parents = []) => {
+  const paths = [];
+
+  for (const node of nodes) {
+    const {id} = node;
+
+    if (!nodeHasChildren(node) || !isNodeExpanded(node)) {
+      paths.push(parents.concat(id));
+    } else {
+      paths.push(parents.concat(id));
+      paths.push(...getFlattenedTreePaths(node.children, [...parents, id]));
+    }
+  }
+
+  return paths;
+};