Skip declaration-site variance for invariant storage

[martinfrancois]

Suggested review order: 11 of 52 (Score: 7.5)
Review first: #990

What's changed?

Leaves a declaration-site type unchanged when the parameter is stored directly in an invariant field or explicitly typed local variable. Parameters remain eligible when their destination already accepts the proposed variance or when an adapter expression is stored instead.

What's your motivation?

Recipe: org.openrewrite.staticanalysis.CommonDeclarationSiteTypeVariances.

I found this by running org.openrewrite.staticanalysis.CommonDeclarationSiteTypeVariances, which configures DeclarationSiteTypeVariance, from org.openrewrite.recipe:rewrite-static-analysis:2.39.0 on ConfigResolver.java in Symphony-Trello at a8013f27. I reproduced the same result with the latest released recipe artifact, org.openrewrite.recipe:rewrite-static-analysis:2.41.0. The recipe changed 18 files, and ./mvnw -DskipTests compile then reported four incompatible-type errors.

Before

private final Function<String, Optional<String>> environmentResolver;

public ConfigResolver(Function<String, Optional<String>> environmentResolver) {
    this.environmentResolver = environmentResolver;
}

Actual after the recipe

private final Function<String, Optional<String>> environmentResolver;

public ConfigResolver(Function<? super String, ? extends Optional<String>> environmentResolver) {
    this.environmentResolver = environmentResolver;
}

Expected after the recipe

(unchanged)

The wildcarded parameter is not assignable to the invariant field. The recipe therefore turns compiling production code into code that does not compile.

Confirmed real-world execution

• Project: Symphony-Trello.
• Location: ConfigResolver.java at a8013f27.
• Discovery checkout: martinfrancois/symphony-trello@a8013f27.

Anything in particular you'd like reviewers to focus on?

Please review the direct-storage boundary. Tim te Beek preferred this approach: skip variance where direct invariant storage makes it invalid, while retaining valid conversions instead of widening unrelated fields.

Have you considered any alternatives or workarounds?

Widening the destination field would expand the recipe beyond declaration-site parameter variance and change APIs and later uses. Skipping only the invalid parameter conversion keeps the change local.

Any additional context

Pre-existing tests changed: None.

• Target commit: martinfrancois/symphony-trello@a8013f27
• Discovery release: org.openrewrite.recipe:rewrite-static-analysis:2.39.0
• Latest verification release: org.openrewrite.recipe:rewrite-static-analysis:2.41.0
• Latest-release compile failures: ConfigResolver, TrelloBoardSetup, GitHubConfigurator, and SetupSystemProperties
• Focused tests: DeclarationSiteTypeVarianceTest

This change was prepared with AI assistance. I reviewed the target execution evidence, implementation, tests, and contribution text.

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've run ./gradlew build locally, and committed any resulting changes to recipes.csv
• I've formatted the lines I changed, without reformatting code I didn't touch