Add @Nullable to a method that can return null
io.moderne.nullability.AddNullableToNullReturningMethodio.moderne.recipe:rewrite-nullabilityAdds 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.
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.AddNullableToNullReturningMethodIf the recipe isn’t available locally, install it with:
mod config recipes jar install io.moderne.recipe:rewrite-nullability:0.3.1Options
| 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