How to properly access properties & getters using LintRuleNodeRegistry (context.registry.addXXX) ?

[evaisse]

Hello, firstly, thank for this very usefull package,

I try to detect dangerous usage of iterator methods which are not null safety, list list.first, list.last, list[2].

Using the context.registry LintRuleNodeRegistry, what's the right listener to detect call of getters on an given object.

For example, regarding the following code :

final myList = <String>[];

void myTest() {
  final a = myList.first; //  that's what I try to detect
  final b = myList[42]; //  that's what I try to detect
  a.replaceFirst("a", "b"); //  this one is correctly detected by `addMethodInvocation`
}

For example I try to detect the myList.first node, and ensure that myList is instance of List. Using context.registry.addIdentifier I did found the right node, but I'm not sure I can get the correlation between the target and the method/propertyName.

node.childEntities give me an approximate answer like : [myList, ., first]

Is there any better way to get an invocation of an object getter or simply access to object property ?

thx

[rrousselGit]

You can look for Identifier & subclasses for myList.first.
I don't remember what's for [x] operators, but that's likely going to be an Expression subclass.

One thing you can do to help debug is use a low-level addNode or addExpression or another general interface, and log print('$node ${node.runtimeType}').
Then you'd know what object type you're looking for.

[evaisse]

Great, thank you, I found out that addPrefixedIdentifier did the job for getting the getter, and addMethodInvocation for method call.
Do you know if there is some kind of cookbook or reference ? I could add some hints, since I'm looking for pretty much any kind of expression.

[rrousselGit]

I'm not aware of one. The analyer API isn't that well documented, and constantly evolves as Dart changes

[evaisse]

Ok would you allow me to add some samples to the exemple project or to extends the doc as a quick cookbook ?

Do you known if there is a way in the current state of the analyzer to detect function that throws ? I suppose any external lib will be ignored by the analyzer, but I can manage to detect throws expression in current analyzed scope.

[rrousselGit]

Depends on the sample/example/doc. I'd like to avoid having custom_lint serve as a documentation for analyzer

If analyzer needs doc and you want to make PRs, it'd probably make more sense to contribute to the analyzer docs directly.