feat: adds the checkNested function with unit tests

README.md

@@ -33,4 +33,5 @@ This is a tiny library of javascript functions, currently comprising:
 - isEqual
 - inPlaceShuffle
 - regularShuffle
+- checkNested
 

src/checkNested.js

@@ -0,0 +1,35 @@
+/**
+ * A function to deeply compare objects
+ * @param {Object} obj - Object to examine
+ * @param {String} key you are searching for
+ * @return {Boolean}
+ */
+
+const checkNested = (object, searchKey) => {
+  // If bad input, return false:
+  if (object === null || object === undefined) {
+    return false;
+  }
+
+  for (let key of Object.keys(object)) {
+    // Iterate through keys for match:
+    if (key === searchKey) {
+      return true;
+    } else {
+      const aNestedObject = object[key];
+
+      // If key isn't a match, try to see if the key's value is an object.
+      // if it is, we need to search through it's keys:
+      if (typeof aNestedObject === 'object') {
+        // We can recursively search for our searchKey in
+        // nested value, passing in objectSubKey (nested object) this time:
+        if (checkNested(aNestedObject, searchKey) === true) {
+          return true;
+        }
+      }
+    }
+  }
+  return false;
+};
+
+module.exports = checkNested;

src/index.js

@@ -5,6 +5,7 @@ export { default as peek } from './peek.js';
 export { default as sieveOfE } from './sieveOfE.js';
 export { default as sort } from './sort.js';
 export { default as camelCase } from './camelCase.js';
+export { default as checkNested } from './checkNested';
 export { default as isEqual } from './isEqual';
 export { default as inPlaceShuffle } from "./inPlaceShuffle.js";
 export { default as regularShuffle } from "./regularShuffle.js";

src/tests/checkNested.test.js

@@ -0,0 +1,27 @@
+const expect = require('chai').expect;
+const checkNested = require('../').checkNested;
+
+describe('checkNested', () => {
+  it('returns true if object contains search key', () => {
+    const object = {
+      name: {
+        first: 'Pete',
+        favorite: {
+          color: 'blue',
+        },
+      },
+    };
+    expect(checkNested(object, 'favorite')).to.equal(true);
+  });
+  it('returns false if object does not contain search key', () => {
+    const object = {
+      name: {
+        first: 'Pete',
+        favorite: {
+          color: 'blue',
+        },
+      },
+    };
+    expect(checkNested(object, 'movie')).to.equal(false);
+  });
+});