Update SA1131 to treat methods as constants

[bjornhellander]

Fixes #3677

[codecov]

Codecov Report

Merging #3710 (6c265cc) into master (d1c94ed) will increase coverage by 0.06%.
Report is 9 commits behind head on master.
The diff coverage is n/a.

❗ Current head 6c265cc differs from pull request most recent head dfd5ed2. Consider uploading reports for the commit dfd5ed2 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3710      +/-   ##
==========================================
+ Coverage   93.06%   93.12%   +0.06%     
==========================================
  Files        1088     1088              
  Lines      114954   115014      +60     
  Branches     4088     4113      +25     
==========================================
+ Hits       106982   107111     +129     
+ Misses       6926     6862      -64     
+ Partials     1046     1041       -5     

[sharwell]

💡 It's also possible to do this:

case IFieldSymbol { IsStatic: true, IsReadOnly: true }:

[sharwell]

💡 Typically we would want the inputs to the test to be parameters, but the outputs to be computed within the test method. In this case, shouldTrigger should be a local variable and not a parameter, calculated like this:

bool shouldTrigger = (expr1, expr2) switch
{
  ("Method1", "arg") => true,
  // ... remaining inputs
  _ => throw new NotSupportedException(),
};

[bjornhellander]

Alright. I will try to remember 👍