add rule Convert string to character about meziantou.analyzer

[meziantou]

Implementation note:

• Contains: already handled by CA1847 => Don't duplicate the case
• IndexOf(string) != IndexOf(char)
• IndexOf(string, Ordinal) == IndexOf(char)
• IndexOf(string, StringComparison) == IndexOf(char, StringComparison)
• Replace(string, string) == Replace(char, char)
• Replace(string, string, Ordinal) == Replace(char, char)

I suggest to change the points related to improvement to warning

This rule suggests performance improvements. The code behave correctly and doesn't need to be changed or reviewed most of the time. So, this is a suggestion.

If performance is important in your project, you can change the diagnostic level using an editorconfig.

[meziantou]

There are already multiple rules:

• https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/ca1847?WT.mc_id=DT-MVP-5003978
• https://github.com/meziantou/Meziantou.Analyzer/blob/main/docs/Rules/MA0089.md

Some calls may be missing from MA0089. Could you check MA0089 and CA1847 and list what optimizations are missing?

[EngRajabi]

I checked. This roll of yours works correctly. But because the default is suggestion. I didn't notice. But does this roll also work for Contains or not? And why didn't you add the roll as a warning?

[meziantou]

But because the default is suggestion. I didn't notice

Most performance rules are suggestion

But does this roll also work for Contains or not

The rule only considers StartsWith and EndsWith. We can add more methods if needed. Let's start a list:

• string.Contains

Feel free to continue this list 🙂

[EngRajabi]

*indexof
*replace
With these 2 items. There are 3 items in total.
I suggest to change the points related to improvement to warning