Add phpstan-phpunit phpstan-strict-rules to phpstan analysis

[phil-davis]

see my comments - fixes a few edge-cases when a URI component might be the string "0" (path, username, query, fragment...). These are not really common in everyday use!

Gets the strict phpstan rules passing.

[codecov]

Codecov Report

Merging #90 (5ff60c8) into master (85d9f7c) will decrease coverage by 1.09%.
The diff coverage is 94.87%.

@@            Coverage Diff             @@
##           master      #90      +/-   ##
==========================================
- Coverage   98.80%   97.72%   -1.09%     
==========================================
  Files           1        1              
  Lines         168      176       +8     
==========================================
+ Hits          166      172       +6     
- Misses          2        4       +2     

Impacted Files	Coverage Δ
lib/functions.php	97.72% <94.87%> (-1.09%)	⬇️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[phil-davis]

------ ---------------------------------------------------------------------- 
  Line   lib/functions.php                                                     
 ------ ---------------------------------------------------------------------- 
  65     Short ternary operator is not allowed. Use null coalesce operator if  
         applicable or consider using long ternary.                            
  90     Construct empty() is not allowed. Use more strict comparison.         
  90     Construct empty() is not allowed. Use more strict comparison.         
  90     Construct empty() is not allowed. Use more strict comparison.         
  116    Construct empty() is not allowed. Use more strict comparison.         
  144    Construct empty() is not allowed. Use more strict comparison.         
  152    Construct empty() is not allowed. Use more strict comparison.         
  254    Construct empty() is not allowed. Use more strict comparison.         
  256    Construct empty() is not allowed. Use more strict comparison.         
  259    Construct empty() is not allowed. Use more strict comparison.         
  264    Construct empty() is not allowed. Use more strict comparison.         
  268    Construct empty() is not allowed. Use more strict comparison.         
  273    Construct empty() is not allowed. Use more strict comparison.         
  276    Construct empty() is not allowed. Use more strict comparison.         
  279    Construct empty() is not allowed. Use more strict comparison.         
 ------ ---------------------------------------------------------------------- 

I will have a go at refactoring these. But it often seems a bit painful to remove use of empty() - need to check if something is null, the empty string etc.

[staabm]

if you don't see value in changing existing code, or don't have time todo it now, feel free to create a baseline for them.

[phil-davis]

These changes from !empty() to isset() now allow the value to be "0".
I added unit test cases for ways that I could see that the value of these things might be "reasonably" passed in as the value "0". For example, a user "name" might be the string "0"! Or the query string could be just ?0 (very edge case - an application that just sends a number in the query string). Or the fragment could be #0. All of those unit test cases fail with the !empty() check, and pass with isset()

[phil-davis]

Note: we need to use isset() because the $parts array passed to build() may not have all the component keys set.

In other places we could compare directly to null because resolve(), normalize() etc. we guarantee that all the URI components are actually set in the array (and "missing" components are set to value null

[phil-davis]

@staabm please review.

[staabm]

lgtm - except a few nits

thank you

[phil-davis]

I broke a heap of unit tests - I will look...

[staabm]

lgtm