Moderne licensed

Add `@Nullable` to a method that can return null

Recipe IDio.moderne.nullability.AddNullableToNullReturningMethodArtifactio.moderne.recipe:rewrite-nullability

Adds JSpecify @Nullable to a method or lambda whose effective return type is non-null but that returns a provably-nullable value, a NullAway error inside a @NullMarked scope. A regular method has its return type widened to JSpecify @Nullable in the type-use position; when the non-null return contract cannot be widened (an override of a non-null supertype return, or a lambda whose functional-interface return is non-null) the returned expression is wrapped in java.util.Objects.requireNonNull(...) instead, leaving runtime behavior unchanged. Nullability is determined from type attribution, and an unconditional return null is left for a human. The recipe is idempotent and conservative; only Java sources are modified.

Single recipeProprietary

Add to your build

Get a download tokenThis recipe is Moderne licensed, so the token must belong to a Moderne customer. It replaces YOUR_DOWNLOAD_TOKEN below.

~/.gradle/gradle.properties

codeGenomeUsername=you@example.com
codeGenomeToken=YOUR_DOWNLOAD_TOKEN

build.gradle.kts

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

rewrite {
    activeRecipe("io.moderne.nullability.AddNullableToNullReturningMethod")
}

repositories {
    mavenCentral()
    maven {
        url = uri("https://artifacts.codegenomeproject.org/maven")
        credentials {
            username = providers.gradleProperty("codeGenomeUsername").get()
            password = providers.gradleProperty("codeGenomeToken").get()
        }
    }
}

dependencies {
    rewrite("io.moderne.recipe:rewrite-nullability:0.6.0")
}

Then run

./gradlew rewriteRun

Usage

This recipe has no required configuration options. You’ll need the Moderne CLI configured before running the command below.

mod run . --recipe io.moderne.nullability.AddNullableToNullReturningMethod

If the recipe isn’t available locally, install it with:

mod config recipes jar install io.moderne.recipe:rewrite-nullability:RELEASE

Options

Name	Type	Description
`annotatedPackages`	`String`	Comma-separated package prefixes to limit the fix to (matching NullAway's `AnnotatedPackages` option). When unset, the recipe fixes all packages. e.g. `com.example`

Data tables

Structured output this recipe can produce.

Null-safety fixes by rungEach residual null-safety fix applied, tagged with the precedence rung that produced it, so the share bottoming out at a last-resort `requireNonNull` assertion can be tracked.io.moderne.nullability.table.NullFixes
Declined null-safety fixes needing reviewEach site the recipe declined to auto-fix because the fix is a design decision (the value is explicitly `null` on some path, so the slot likely should be `@Nullable`), for human triage.io.moderne.nullability.table.DeclinedNullFixes
Source files that had resultsSource files that were modified by the recipe run.org.openrewrite.table.SourcesFileResults
Source files that had search resultsSearch results that were found during the recipe run.org.openrewrite.table.SearchResults
Source files that errored on a recipeThe details of all errors produced by a recipe run.org.openrewrite.table.SourcesFileErrors
Recipe performanceStatistics used in analyzing the performance of recipes.org.openrewrite.table.RecipeRunStats