Basic loop

src/lib/tree.test.ts

@@ -0,0 +1,21 @@
+import im from 'immutable'
+import { setPointsInTree } from './tree'
+
+it('sets points on an empty tree', () => {
+  const tree = im.List()
+  expect(setPointsInTree(tree, 2, 5).toJS()).toEqual([0, 0, 5])
+})
+
+it('sets points in the end of the current range', () => {
+  const tree = im.List([0, 1])
+  expect(setPointsInTree(tree, 2, 5).toJS()).toEqual([0, 1, 5])
+})
+it('sets points in the middle of the current range', () => {
+  const tree = im.List([0, 0, 0, 0, 0, 0, 5])
+  expect(setPointsInTree(tree, 2, 5).toJS()).toEqual([0, 0, 5, 0, 0, 0, 5])
+})
+
+it('does not mutate the tree for points already set', () => {
+  const tree = im.List([0, 3, 2, 0, 5])
+  expect(setPointsInTree(tree, 1, 3)).toStrictEqual(tree)
+})