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Hoist a guarded @Nullable field read into a local variable

Recipe IDio.moderne.nullability.HoistNullableFieldReadIntoLocal
Artifactio.moderne.recipe:rewrite-nullability

NullAway cannot refine a @Nullable field across a dereference, because the field could be mutated between the null check and the use, so if (this.f != null) { this.f.foo(); } is rejected. This recipe reads the field into a local once before the if — String f = this.f; if (f != null) { f.foo(); } — which NullAway can refine. Only @Nullable instance fields guarded by a != null check are rewritten, and the field must not be reassigned inside the then-block.

Single recipeProprietary

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.HoistNullableFieldReadIntoLocal

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

mod config recipes jar install io.moderne.recipe:rewrite-nullability:0.3.1

Data tables

Structured output this recipe can produce.

  • 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