--update: added max char problem

Author: ashokdey

Diff for: src/maxchar/index.js

@@ -0,0 +1,33 @@
+function findMaxchar(str) {
+  if (typeof str !== 'string') {
+    throw new Error('Invalid Argument');
+  }
+
+  const charMap = {};
+  const lowerCasedString = str.toLowerCase();
+
+  lowerCasedString.split('').forEach((char) => {
+    if (!charMap[char]) {
+      charMap[char] = 1;
+    } else {
+      charMap[char] += 1;
+    }
+  });
+
+  // find the char with highest score
+  let max = charMap[lowerCasedString[0]];
+  let char = lowerCasedString[0];
+
+  Object.keys(charMap).forEach((e) => {
+    if (charMap[e] > max) {
+      max = charMap[e];
+      char = e;
+    }
+  });
+
+  return char;
+}
+
+module.exports = {
+  findMaxchar,
+};

Diff for: src/maxchar/maxchar.test.js

@@ -0,0 +1,15 @@
+const { findMaxchar } = require('.');
+
+describe('MaxChar', () => {
+  it('Should throw error for invalid argument', () => {
+    expect(() => findMaxchar(21)).toThrow('Invalid Argument');
+  });
+
+  it('Should return `l` for given string `Hello World`', () => {
+    expect(findMaxchar('Hello World')).toEqual('l');
+  });
+
+  it('Should return `a` for given string `A wonderful day`', () => {
+    expect(findMaxchar('A wonderful day')).toEqual('a');
+  });
+});