2 years ago

When you're learning to write custom rules for https://phpstan.org/developing-extensions/rules or https://github.com/rectorphp/rector/blob/main/docs/create_own_rule.md, you'll have to learn more about the PHP programming language as well. To be more precise, about the way the interpreter parses PHP code. The result of parsing PHP code is a tree of nodes which represents the structure of the code, e.g. you'll have a Class definition node, a Method definition node, and within those method Statement nodes, and so on.

The tree of nodes is called Abstract Syntax Tree, and a successful PHPStan or Rector rule starts with selecting the right nodes from the tree and "subscribing" your rule to these nodes.