xmllint to lint XML files.
brew install xmlstarlet
A lot of payment providers use JSON driven API’s. Also in WordPress and the WordPress Pay library jSON is used very often. WordPress and PHP JSON functions are used very often. Since we increased the minimal PHP version to 5.6 (or higher) we also start to use
In the WordPress Pay library we will try to use Fully Qualified names (FQN) to take full advantage of PHP opcode. The “Slevomat Coding Standard” library can be used to check on this.