Properly use declaration-site type variance for well-known types

org.openrewrite.staticanalysis.CommonDeclarationSiteTypeVariances

When using a method parameter like Function<IN, OUT>, it should rather be Function<? super IN, ? extends OUT>. This recipe checks for method parameters of well-known types.

Tags

• RSPEC-S1217

Recipe source

GitHub, Issue Tracker, Maven Central

• groupId: org.openrewrite.recipe

• artifactId: rewrite-static-analysis

• version: 1.5.0

Usage

This recipe has no required configuration options. It can be activated by adding a dependency on org.openrewrite.recipe:rewrite-static-analysis:1.5.0 in your build file or by running a shell command (in which case no build changes are needed):

Gradle

1. Add the following to your build.gradle file:

build.gradle

plugins {
    id("org.openrewrite.rewrite") version("6.12.0")
}

rewrite {
    activeRecipe("org.openrewrite.staticanalysis.CommonDeclarationSiteTypeVariances")
}

repositories {
    mavenCentral()
}

dependencies {
    rewrite("org.openrewrite.recipe:rewrite-static-analysis:1.5.0")
}

2. Run gradle rewriteRun to run the recipe.

Gradle init script

1. Create a file named init.gradle in the root of your project.

init.gradle

initscript {
    repositories {
        maven { url "https://plugins.gradle.org/m2" }
    }
    dependencies { classpath("org.openrewrite:plugin:6.12.0") }
}
rootProject {
    plugins.apply(org.openrewrite.gradle.RewritePlugin)
    dependencies {
        rewrite("org.openrewrite.recipe:rewrite-static-analysis:1.5.0")
    }
    rewrite {
        activeRecipe("org.openrewrite.staticanalysis.CommonDeclarationSiteTypeVariances")
    }
    afterEvaluate {
        if (repositories.isEmpty()) {
            repositories {
                mavenCentral()
            }
        }
    }
}

2. Run gradle --init-script init.gradle rewriteRun to run the recipe.

Maven POM

1. Add the following to your pom.xml file:

pom.xml

<project>
  <build>
    <plugins>
      <plugin>
        <groupId>org.openrewrite.maven</groupId>
        <artifactId>rewrite-maven-plugin</artifactId>
        <version>5.29.0</version>
        <configuration>
          <activeRecipes>
            <recipe>org.openrewrite.staticanalysis.CommonDeclarationSiteTypeVariances</recipe>
          </activeRecipes>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.openrewrite.recipe</groupId>
            <artifactId>rewrite-static-analysis</artifactId>
            <version>1.5.0</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>

2. Run mvn rewrite:run to run the recipe.

Maven Command Line

shell

mvn -U org.openrewrite.maven:rewrite-maven-plugin:run -Drewrite.recipeArtifactCoordinates=org.openrewrite.recipe:rewrite-static-analysis:RELEASE -Drewrite.activeRecipes=org.openrewrite.staticanalysis.CommonDeclarationSiteTypeVariances

Moderne CLI

You will need to have configured the Moderne CLI on your machine before you can run the following command.

shell

mod run . --recipe CommonDeclarationSiteTypeVariances

Definition

Recipe List

• Properly use declaration-site type variance

  • variantTypes: [java.util.function.Consumer<IN>, java.util.function.BiPredicate<IN, IN>, java.util.function.DoubleFunction<OUT>, java.util.function.Function<IN, OUT>, java.util.function.IntFunction<OUT>, java.util.function.LongFunction<OUT>, java.util.function.ObjDoubleConsumer<IN>, java.util.function.ObjIntConsumer<IN>, java.util.function.ObjLongConsumer<IN>, java.util.function.Predicate<IN>, java.util.function.Supplier<OUT>, java.util.function.ToDoubleBiFunction<IN, IN>, java.util.function.ToDoubleFunction<IN>, java.util.function.ToIntBiFunction<IN, IN>, java.util.function.ToIntFunction<IN>, java.util.function.ToLongBiFunction<IN, IN>, java.util.function.ToLongFunction<IN>]

Yaml Recipe List

---
type: specs.openrewrite.org/v1beta/recipe
name: org.openrewrite.staticanalysis.CommonDeclarationSiteTypeVariances
displayName: Properly use declaration-site type variance for well-known types
description: When using a method parameter like `Function<IN, OUT>`, it should rather be `Function<? super IN, ? extends OUT>`. This recipe checks for method parameters of well-known types.
tags:
  - RSPEC-S1217
recipeList:
  - org.openrewrite.staticanalysis.DeclarationSiteTypeVariance:
      variantTypes: [java.util.function.Consumer<IN>, java.util.function.BiPredicate<IN, IN>, java.util.function.DoubleFunction<OUT>, java.util.function.Function<IN, OUT>, java.util.function.IntFunction<OUT>, java.util.function.LongFunction<OUT>, java.util.function.ObjDoubleConsumer<IN>, java.util.function.ObjIntConsumer<IN>, java.util.function.ObjLongConsumer<IN>, java.util.function.Predicate<IN>, java.util.function.Supplier<OUT>, java.util.function.ToDoubleBiFunction<IN, IN>, java.util.function.ToDoubleFunction<IN>, java.util.function.ToIntBiFunction<IN, IN>, java.util.function.ToIntFunction<IN>, java.util.function.ToLongBiFunction<IN, IN>, java.util.function.ToLongFunction<IN>]

See how this recipe works across multiple open-source repositories

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Contributors

Jonathan Schneider, Tim te Beek, Knut Wannheden, Sam Snyder