Fix bug in replace_all

[matt439]

Description

While creating unit tests, I identified a bug in the replace_all function which causes an infinite loop if the substr argument is an empty string. I added a check at the beginning of the function which detects if the sub-string is empty. If so, the input string text is returned.

There are multiple ways to handle this edge case. One is to throw an exception, another is to return an empty string. I believe the most logical response it to return the unaltered input string as it shows to the user that no action will be taken with an empty sub-string.

This is not a breaking change as the current behavior always results in a program crash.

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

I added an extra line of testing to test_text.cpp which uses an empty string as the substr argument. It runs as expected. In a separate pull request, I have created unit testing for replace_all which also tests this function's edge cases.

Testing Checklist

• Tested with sktest

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• My changes generate no new warnings

[Liquidscroll]

This looks good to me! I think it makes sense to return the entire input text when the substring is empty, I think it's pretty logical.

[DarrenSunandar]

This pull request is well-structured and logical change made. The early check for an empty substring ensures that the function won't crash. Also, nice to ensures that when the substring is empty, the original string is returned, preventing an infinite loop.

[WhyPenguins]

Looks good!