getLeafNodes.js

function getLeafNodes(data) {
  const leafNodes = [];

  function traverse(node) {
    if (node.children.length === 0) {
      leafNodes.push(node.name);
    } else {
      for (let i = 0; i < node.children.length; i++) {
        traverse(node.children[i]);
      }
    }
  }

  traverse(data);

  return leafNodes;
}

// Unit tests

// Test case 1: Basic example
const input1 = {
  name: "A",
  children: [
    {
      name: "B",
      children: [
        {
          name: "C",
          children: [],
        },
      ],
    },
    {
      name: "D",
      children: [],
    },
  ],
};
const expectedOutput1 = ["C", "D"];
const actualOutput1 = getLeafNodes(input1);
console.log(JSON.stringify(actualOutput1) === JSON.stringify(expectedOutput1)); // Output: true

// Test case 2: Tree with multiple levels of leaf nodes
const input2 = {
  name: "A",
  children: [
    {
      name: "B",
      children: [
        {
          name: "C",
          children: [],
        },
        {
          name: "D",
          children: [],
        },
      ],
    },
    {
      name: "E",
      children: [
        {
          name: "F",
          children: [],
        },
        {
          name: "G",
          children: [],
        },
      ],
    },
  ],
};
const expectedOutput2 = ["C", "D", "F", "G"];
const actualOutput2 = getLeafNodes(input2);
console.log(JSON.stringify(actualOutput2) === JSON.stringify(expectedOutput2)); // Output: true

// Test case 3: Tree with a single leaf node
const input3 = {
  name: "A",
  children: [
    {
      name: "B",
      children: [],
    },
  ],
};
const expectedOutput3 = ["B"];
const actualOutput3 = getLeafNodes(input3);
console.log(JSON.stringify(actualOutput3) === JSON.stringify(expectedOutput3)); // Output: true

// Test case 4: Tree with no leaf nodes
const input4 = {
  name: "A",
  children: [],
};
const expectedOutput4 = ["A"];
const actualOutput4 = getLeafNodes(input4);
console.log(JSON.stringify(actualOutput4) === JSON.stringify(expectedOutput4)); // Output: true