Mutator/mbstring

[majkel89]

This PR:

• Adds mbstring extension mutator (MBString)
• Covered by tests
• Doc PR: #654 mbstring mutator doc site#122

Relates to issue #654

Converts function calls like mb_chr(74, 'utf-8'), mb_strlen('test', 'utf-8') to chr('test'), strlen('test').

Supported functions:

Pay attention to the function mapping when doing code review.

• mb_chr -> chr
• mb_ord -> ord
• mb_parse_str -> parse_str
• mb_send_mail -> mail
• mb_strcut -> substr
• mb_stripos -> stripos
• mb_stristr -> stristr
• mb_strlen -> strlen
• mb_strpos -> strpos
• mb_strrchr -> strrchr
• mb_strripos -> strripos
• mb_strrpos -> strrpos
• mb_strstr -> strstr
• mb_strtolower -> strtolower
• mb_strtoupper -> strtoupper
• mb_substr_count -> substr_count
• mb_substr -> substr
• mb_convert_case -> strtolower, strtoupper, ucwords depending on mode argument

New profile @extensions created to hold this mutator. It is on by default.

Configuration

    "mutators": {
        "MBString": {
            "settings": {
                "mb_strlen": false,
                "mb_ord": false,
            }
        }
    },

[majkel89]

I will have to test it a little bit longer so that this mutator will not produce mutats that will be killed by differences in mb string functions and std string functions.

[majkel89]

I have tested the mapping and removed functions that cannot be easily mapped:

• mb_split - uses regular expressions like ereg functions
• mb_strrichr - have no equivalent in standard string functions

[majkel89]

final fixes added and doc PR created. I think this PR is polished enough to be merged

[maks-rafalko]

Looks very nice 👍

[majkel89]

could you merge this PR ?

[sanmai]

The mutator could be simplified if we add a workaround against missing constants to the test.

[sanmai]

I'm sorry for going back and forth with this PR, but there isn't a test case for a mixed-case replacement as far as I can see, but please correct me if I overlook.

E.g. a test case displaying that this replacement happens:

- MB_Chr(74);
+ chr(74);

This is customary for other mutators, an example.

Other than that you're doing a beautiful work!

[BackEndTea]

Great PR,

Only thing i'm missing is that a testcase function call with a variable name is not mutated. (And mostly that it doesn't crash)

e.g.

$a = 'mb_chr'
$a(74)

Should not mutate, and not crash.

[maks-rafalko]

Thank you @majkel89 👍