feat: 'String incrementer'

kata/5 kyu/string-incrementer/index.test.ts

@@ -0,0 +1,14 @@
+import incrementString from '.';
+
+describe('incrementString', () => {
+  it('should increment number in string', () => {
+    expect.assertions(6);
+
+    expect(incrementString('foobar000')).toBe('foobar001');
+    expect(incrementString('foo')).toBe('foo1');
+    expect(incrementString('foobar001')).toBe('foobar002');
+    expect(incrementString('foobar99')).toBe('foobar100');
+    expect(incrementString('foobar099')).toBe('foobar100');
+    expect(incrementString('')).toBe('1');
+  });
+});

kata/5 kyu/string-incrementer/index.ts

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+function incrementString(strng: string): string {
+  const { groups } = strng.match(/(?<string>[a-zA-Z]+)?(?<number>\d+)?/) || [];
+
+  if (!groups) {
+    throw new Error('Invalid input');
+  }
+
+  const { string = '', number = '0' } = groups;
+
+  const numberLength = number.length;
+  const parsedNumber = parseInt(number, 10);
+
+  return string + (parsedNumber + 1).toString().padStart(numberLength, '0');
+}
+
+export default incrementString;

kata/5 kyu/string-incrementer/readme.md

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+# [String incrementer](https://www.codewars.com/kata/54a91a4883a7de5d7800009c)
+
+Your job is to write a function which increments a string, to create a new string.
+
+- If the string already ends with a number, the number should be incremented by 1.
+- If the string does not end with a number. the number 1 should be appended to the new string.
+
+Examples:
+
+`foo -> foo1`
+
+`foobar23 -> foobar24`
+
+`foo0042 -> foo0043`
+
+`foo9 -> foo10`
+
+`foo099 -> foo100`
+
+_Attention: If the number has leading zeros the amount of digits should be considered._
+
+---
+
+## Tags
+
+- Advanced Language Features
+- Algorithms
+- Data Types
+- Declarative Programming
+- Fundamentals
+- Logic
+- Parsing
+- Programming Paradigms
+- Regular Expressions
+- Strings