Remove method throws

[ghusta]

What problem are you trying to solve?

I need to remove some exceptions from the method throws clause (see JLS spec).
That's why I'd like to add this recipe.
The recipe is planned to be used on method declaration.

What precondition(s) should be checked before applying this recipe?

Precondition DeclaresMethod using a method pattern.

Describe the situation before applying the recipe

import java.io.IOException;

class A {
    public void foo() throws IOException {
        // no-op
    }
}

Describe the situation after applying the recipe

class A {
    public void foo() {
        // no-op
    }
}

Have you considered any alternatives or workarounds?

None found.

Any additional context

The options planned for this recipe, so far:

• methodPattern
• exceptionType (FQN)
• matchOverrides (true by default), useful for MethodMatcher
• removeAll (false by default) -- if true, exceptionType is ignored

Are you interested in contributing this recipe to OpenRewrite?

Yes, I'll submit a PR.

[timtebeek]

hey! Thanks for the suggestion and implementation; Just wondering if you had also come across or considered:
https://docs.openrewrite.org/recipes/staticanalysis/unnecessarythrows

That recipe does not take a method pattern like yours, but does remove throws declarations anywhere they might not be needed. As compared to your recipe approach I wonder if that latter one might be a little too specific to a particular method pattern, and thus has limited use. Could you explain where you aim to use this recipe?

[ghusta]

Hello Tim

I'm going to explain the full context so that you can understand my actual need.

I have some project to upgrade to Spring Security 7.0.
It uses a custom configurer using the class AbstractHttpConfigurer, as documented here (note: the example in the doc is partially incorrect with the current version).

The problem is that the signature of the methods init and configure has changed, with the removal of the throws clause, in the top level interface SecurityConfigurer, and its subclasses.
The source of this change is the commit spring-projects/spring-security@667cd4a, motivated by the issue spring-projects/spring-security#17957.

For example with Spring Security 6, we would have something like:

public class MyCustomDsl extends AbstractHttpConfigurer<MyCustomDsl, HttpSecurity> {

	@Override
	public void init(HttpSecurity http) throws Exception {
        // ...
	}

	@Override
	public void configure(HttpSecurity http) throws Exception {
        // ...
	}

and with Spring Security 7, it would be:

public class MyCustomDsl extends AbstractHttpConfigurer<MyCustomDsl, HttpSecurity> {

	@Override
	public void init(HttpSecurity http) {
        // ...
	}

	@Override
	public void configure(HttpSecurity http) {
        // ...
	}

So my intention is to provide a recipe which would target a specific method (here init and configure) and remove the exception from the throws clause. And it could be applied in Migration to Spring Security 7.0.
That's why I started this recipe.

[timtebeek]

Thanks for that context! Seems like a reasonable request then indeed. I'll try to fit in a review soon-ish.