add findInTree function in utils

web/static/src/ts/core/utils.ts

@@ -83,3 +83,23 @@ export function debounce(
     }
   };
 }
+
+interface Tree<T> {
+  children: T[];
+}
+
+export function findInTree<T extends Tree<T>>(
+  tree: T,
+  predicate: (t: T) => boolean
+): T | null {
+  if (predicate(tree)) {
+    return tree;
+  }
+  for (let child of tree.children) {
+    let match = findInTree(child, predicate);
+    if (match) {
+      return match;
+    }
+  }
+  return null;
+}

web/static/tests/core/utils.test.ts

@@ -3,7 +3,8 @@ import {
   htmlTrim,
   idGenerator,
   memoize,
-  debounce
+  debounce,
+  findInTree
 } from "../../src/ts/core/utils";
 
 describe("escape", () => {
@@ -77,3 +78,16 @@ describe("debounce", () => {
     expect(n).toBe(1);
   });
 });
+
+describe("findInTree", () => {
+  test("can find stuff in tree", () => {
+    let tree = {
+      id: 1,
+      children: [{ id: 2, children: [] }, { id: 3, key: "hello", children: [] }]
+    };
+    const match1 = findInTree(tree, t => t.id === 3);
+    expect((<any>match1).key).toBe("hello");
+    const match2 = findInTree(tree, t => t.id === 4);
+    expect(match2).toBe(null);
+  });
+});