fix: Return proper http response codes for errors

[komen205]

Description

Fixes #171

Type of change

• New feature (added a non-breaking change which adds functionality)

How Has This Been Tested?

• Tested locally with a valid username
• Tested locally with an invalid username
• Ran tests with composer test
• Added or updated test cases to test new features

Checklist:

• I have checked to make sure no other pull requests are open for this issue
• The code is properly formatted and is consistent with the existing code style
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

Screenshots

[komen205]

@DenverCoder1 let me know if this works

[DenverCoder1]

The error codes also need to be set when throwing the exception

e.g. for errors that should return 404 response, 404 should be passed as the $code parameter.

throw new InvalidArgumentException("Could not find a user with that name.", 404);

[DenverCoder1]

This looks great! This is a very helpful contribution.

There's still a couple suggestions earlier about the spelling of the parameter name.

Also, on line 21 of index.php, maybe a 500 could be sent when the token is missing from the configuration.

if (!isset($_SERVER["TOKEN"])) {
    $message = file_exists(dirname(__DIR__ . '../.env', 1))
        ? "Missing token in config. Check Contributing.md for details."
        : ".env was not found. Check Contributing.md for details.";
-    renderOutput($message);
+    renderOutput($message, 500);
}

[DenverCoder1]

Looks great! Thanks for the contribution 🎉