simple-cipher: add test to check that messages longer than the key can be decoded.

[paparomeo]

I just come across a solution for the "Simple Cipher" exercise from a student, which could encode messages longer than the key but failed to decode messages longer than the key, and yet, because we haven't a test to cover this, all tests would pass giving an illusion of correctness.

This pull request adds a test to also check that a message longer than the key can be decoded.

Correspondent problem specifications PR: exercism/problem-specifications#1460.

[SleeplessByte]

I think you're trying to decode this.

Suggested change

	expect(new Cipher('abc').encode('iboaqcnecbfcr'))
	expect(new Cipher('abc').decode('iboaqcnecbfcr'))

[SleeplessByte]

Actually, looking at the canonical data, you probably took it from there:

{
  "description": "Can handle messages longer than the key",
  "property": "encode",
  "input": {
    "key": "abc",
    "plaintext": "iamapandabear"
  },
  "expected": "iboaqcnecbfcr"
}

This expects a plaintext of `"iamapandabear" and expected value of "iboaqcnecbfcr" after encode.

[paparomeo]

Silly me. Copy / paste error... 🤦‍♂️. I'll fix as soon as I get home (the invoked method should be decode rather than encode. Actually you've reminded me that I need to update the test canonical data first / instead. Thanks!

[paparomeo]

@SleeplessByte: Fixed! Correspondent problem specifications PR: exercism/problem-specifications#1460.

[paparomeo]

exercism/problem-specifications#1460 has been merged @SleeplessByte.

[SleeplessByte]

You're the best @paparomeo

[junedev]

This was bugging me all the time when mentoring. As I came around to addressing this here I found it was fixed already. Many thanks!