Moderne licensed

Extract a repeated `@Nullable` invocation into a local variable

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

When the same side-effect-free @Nullable method invocation (textually identical receiver, name, and no arguments — e.g. source.get()) appears two or more times in one block, hoists it into a single local @Nullable Type x = source.get(); declared just before the first use and replaces every occurrence with x. NullAway cannot refine a @Nullable return across two separate calls — the second could return a different value — so if (source.get() != null) { source.get().foo(); } is rejected; one local gives the checker a single narrowing point. The rewrite is strictly gated: the call must be provably @Nullable (resolved from the nullability model), side-effect free (only a no-argument getter-style call whose receiver is a simple identifier or this, never an argument-bearing or unresolved-type call), all occurrences must be in the same block, and the receiver must not be reassigned anywhere in that block (which could change the value between calls). A pure call evaluated once rather than N times yields the same value, so runtime behavior is unchanged. 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.ExtractRepeatedNullableInvocationToLocal")
}

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.ExtractRepeatedNullableInvocationToLocal

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