Read below and fill "// Replace this comment with your code... " this section with JavaScript Code please.

/*******************************************************************************

* Problem 3: fix the formatting of Canadian Postal Codes

*

* A Canadian Postal Code (see https://en.wikipedia.org/wiki/Postal_codes_in_Canada)

* is a 6-character string of the following form:

*

* A1A 1A1

*

* There are more than 800K valid postal codes. The first three-characters of

* the postal code is called a "Forward Sortation Area," and represents a geographic

* region, with the first letter representing a province, or part of a province.

*

* The first character in a postal code can be any letter except D, F, I, O, Q, W, U, Z

*

* The other characters (i.e., letters) in a postal code can be any letter except

* D, F, I, O, Q or U (i.e., W and Z are allowed)

*

* The numbers can be anything between 0 and 9

*

* HINT: use a Regular Expression to help you check for valid characters/numbers

*

* Many databases have postal codes that have been manually entered, and contain

* formatting errors. The fixPostalCode() function takes a possible postal code

* (i.e. a string), attempts to format it, and returns the formatted version.

* If the string is not a valid postal code, an error is thrown. See

* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/throw.

*

* @param {string} postalCode - a possible postal code to be formatted

* @returns {string} - a formatted postal code

******************************************************************************/

function fixPostalCode(postalCode) {

// Replace this comment with your code...

}

const { fixPostalCode } = require('./solutions');

describe('Problem 3 - fixPostalCode() function', function () {

test('leading space is removed', function () {

const postalCode = ' A1A 1A1';

expect(fixPostalCode(postalCode)).toEqual(' A1A 1A1');

});

test('trailing space is removed', function () {

const postalCode = 'A1A 1A1 ';

expect(fixPostalCode(postalCode)).toEqual('A1A 1A1 ');

});

test('an internal space is added', function () {

const postalCode = 'A1A1A1';

expect(fixPostalCode(postalCode)).toEqual('A1A1A1');

});

test('lowercase letters are converted to UPPER case', function () {

const postalCode = 'a1a 1a1';

expect(fixPostalCode(postalCode)).toEqual('a1a 1a1');

});

test('a postal code with too many characters throws an error', function () {

const invalidPostalCode = 'A1A 1A11';

expect(() => fixPostalCode(invalidPostalCode)).toThrow();

});

test('a postal code with too few characters throws an error', function () {

const invalidPostalCode = 'A1A';

expect(() => fixPostalCode(invalidPostalCode)).toThrow();

});

test('a postal code that starts with an invalid character throws an error', function () {

// D, F, I, O, Q, W, U, Z are all invalid in the first position

expect(() => fixPostalCode('D1A 1A1')).toThrow();

expect(() => fixPostalCode('F1A 1A1')).toThrow();

expect(() => fixPostalCode('I1A 1A1')).toThrow();

expect(() => fixPostalCode('O1A 1A1')).toThrow();

expect(() => fixPostalCode('Q1A 1A1')).toThrow();

expect(() => fixPostalCode('W1A 1A1')).toThrow();

expect(() => fixPostalCode('U1A 1A1')).toThrow();

expect(() => fixPostalCode('Z1A 1A1')).toThrow();

});

test('a postal code with a non-digit in the second position throws an error', function () {

expect(() => fixPostalCode('DZA 1A1')).toThrow();

});

test('a postal code with an invalid character in the third position throws an error', function () {

// D, F, I, O, Q, U are all invalid in the first position

expect(() => fixPostalCode('A1D 1A1')).toThrow();

expect(() => fixPostalCode('A1F 1A1')).toThrow();

expect(() => fixPostalCode('A1I 1A1')).toThrow();

expect(() => fixPostalCode('A1O 1A1')).toThrow();

expect(() => fixPostalCode('A1Q 1A1')).toThrow();

// W is valid in this position

expect(fixPostalCode('A1W 1A1')).toEqual('A1W 1A1');

expect(() => fixPostalCode('A1U 1A1')).toThrow();

// Z is valid in this position

expect(fixPostalCode('A1Z 1A1')).toEqual('A1Z 1A1');

});

test('a postal code with a non-space or invalid character in the fourth position throws an error', function () {

expect(() => fixPostalCode('AZA-1A1')).toThrow();

expect(() => fixPostalCode('AZA 1A1')).toThrow();

});

test('a postal code with a non-digit in the fifth position throws an error', function () {

expect(() => fixPostalCode('AZAAA1')).toThrow();

expect(() => fixPostalCode('AZA A1')).toThrow();

});

test('a postal code with an invalid character in the sixth position throws an error', function () {

// D, F, I, O, Q, U are all invalid in the sixth position

expect(() => fixPostalCode('A1A 1D1')).toThrow();

expect(() => fixPostalCode('A1A 1F1')).toThrow();

expect(() => fixPostalCode('A1A 1I1')).toThrow();

expect(() => fixPostalCode('A1A 1O1')).toThrow();

expect(() => fixPostalCode('A1A 1Q1')).toThrow();

// W is valid in this position

expect(fixPostalCode('A1A 1W1')).toEqual('A1A 1W1');

expect(() => fixPostalCode('A1A 1U1')).toThrow();

// Z is valid in this position

expect(fixPostalCode('A1A 1Z1')).toEqual('A1A 1Z1');

});

test('a postal code with a non-digit in the seventh position throws an error', function () {

expect(() => fixPostalCode('AZA AAG')).toThrow();

expect(() => fixPostalCode('AZA A1-')).toThrow();

});

});