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Migrate @AutoValue classes to Kotlin data classes

Recipe IDorg.openrewrite.kotlin.migrate.autovalue.AutoValueToDataClass

Artifactorg.openrewrite.recipe:rewrite-migrate-kotlin

Replaces a Java or Kotlin @AutoValue abstract class with a Kotlin data class and rewrites its Kotlin and Java callers: x() accessors become x property reads (getX() in Java) and the static or companion create(..) factory becomes the constructor. A Java class becomes a .kt file in place of the .java file. Only classes consisting of abstract accessors and a single forwarding factory are converted; every @AutoValue class is listed in the AutoValueClasses data table with the reason it was skipped.

Single recipeKotlinModerne Proprietary License

Try in PlatformTry this recipe in the Moderne platform. Not a user yet? You’ll get a no-setup demo environment, with nothing to install or configure.

Options

1 parameters

1 optional

Parameter	Example	Type	Required
keepJavaAccessors	—	Boolean	Optional
Give each property a @get:JvmName matching the AutoValue accessor, so Java call sites such as foo.bar() keep compiling unchanged instead of being rewritten to foo.getBar(). Factories still become constructors. Default false.

Examples

java, kotlin, kotlin

Parameter	Value
keepJavaAccessors	null

java

Before

package com.example.app;

import com.example.Money;

class Checkout {
    String describe(Money price) {
        return price.currency() + price.amount();
    }

    Money free() {
        return Money.create("EUR", 0L, null);
    }
}

After

package com.example.app;

import com.example.Money;

class Checkout {
    String describe(Money price) {
        return price.getCurrency() + price.getAmount();
    }

    Money free() {
        return new Money("EUR", 0L, null);
    }
}

Diff

@@ -7,1 +7,1 @@
class Checkout {
    String describe(Money price) {
-       return price.currency() + price.amount();
+       return price.getCurrency() + price.getAmount();
    }
@@ -11,1 +11,1 @@

    Money free() {
-       return Money.create("EUR", 0L, null);
+       return new Money("EUR", 0L, null);
    }

kotlin

Before

package com.example

import com.google.auto.value.AutoValue

@AutoValue
abstract class Money {
    abstract fun currency(): String
    abstract fun amount(): Long
    abstract fun note(): String?

    companion object {
        @JvmStatic
        fun create(currency: String, amount: Long, note: String?): Money = AutoValue_Money(currency, amount, note)
    }
}

After

package com.example

data class Money(
    val currency: String,
    val amount: Long,
    val note: String?,
)

Diff

@@ -3,1 +3,5 @@
package com.example

-import com.google.auto.value.AutoValue
+data class Money(
+   val currency: String,
+   val amount: Long,
+   val note: String?,
+)

@@ -5,12 +9,0 @@
import com.google.auto.value.AutoValue

-@AutoValue
-abstract class Money {
-   abstract fun currency(): String
-   abstract fun amount(): Long
-   abstract fun note(): String?
-
-   companion object {
-       @JvmStatic
-       fun create(currency: String, amount: Long, note: String?): Money = AutoValue_Money(currency, amount, note)
-   }
-}
-

kotlin

Before

package com.example.app

import com.example.Money

fun describe(price: Money): String = price.currency() + price.amount()

fun free(): Money = Money.create("EUR", 0L, null)

After

package com.example.app

import com.example.Money

fun describe(price: Money): String = price.currency + price.amount

fun free(): Money = Money("EUR", 0L, null)

Diff

@@ -5,1 +5,1 @@
import com.example.Money

-fun describe(price: Money): String = price.currency() + price.amount()
+fun describe(price: Money): String = price.currency + price.amount

@@ -7,1 +7,1 @@
fun describe(price: Money): String = price.currency() + price.amount()

-fun free(): Money = Money.create("EUR", 0L, null)
+fun free(): Money = Money("EUR", 0L, null)

Usage

Run this recipe

This recipe has no required configuration options. Users of Moderne can run it via the 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 AutoValueToDataClass

To also set the recipe's optional settings, add them to the command. The values below are examples, not recommendations; see Options for what each one does.

With optional settings (example values)

mod run . --recipe AutoValueToDataClass --recipe-option "keepJavaAccessors=true"

If the recipe is not available locally, then you can install it using:

RELEASE resolves to the newest release and LATEST to the newest build of any kind, including snapshots. Either one lets mod config recipes upgrade pull in later versions without editing this command; a pinned version stays where you put it.

RELEASE

mod config recipes jar install org.openrewrite.recipe:rewrite-migrate-kotlin:RELEASE

LATEST

mod config recipes jar install org.openrewrite.recipe:rewrite-migrate-kotlin:LATEST

Pinned version

mod config recipes jar install org.openrewrite.recipe:rewrite-migrate-kotlin:0.10.0

Data tables

AutoValue classes

org.openrewrite.kotlin.migrate.autovalue.AutoValueClasses

Every @AutoValue class found, with the reason it was not migrated to a data class where applicable.

Export after a run

mod study . --last-recipe-run \
  --data-table org.openrewrite.kotlin.migrate.autovalue.AutoValueClasses

Column	Description
Source path	The source file declaring the class.
Class name	The fully qualified name of the @AutoValue class.
Skip reason	Why the class was not migrated; empty when it was.
Features	What the class uses beyond plain accessors (builder, @Memoized, supertypes, adapters, custom methods) and how its builder is used at call sites.

Source files that had results

org.openrewrite.table.SourcesFileResults

Source files that were modified by the recipe run.

Export after a run

mod study . --last-recipe-run \
  --data-table org.openrewrite.table.SourcesFileResults

Column	Description
Source path before the run	The source path of the file before the run. null when a source file was created during the run.
Source path after the run	A recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
Parent of the recipe that made changes	In a hierarchical recipe, the parent of the recipe that made a change. Empty if this is the root of a hierarchy or if the recipe is not hierarchical at all.
Recipe that made changes	The specific recipe that made a change.
Estimated time saving	An estimated effort that a developer to fix manually instead of using this recipe, in unit of seconds.
Cycle	The recipe cycle in which the change was made.

Source files that had search results

org.openrewrite.table.SearchResults

Search results that were found during the recipe run.

Export after a run

mod study . --last-recipe-run \
  --data-table org.openrewrite.table.SearchResults

Column	Description
Source path of search result before the run	The source path of the file with the search result markers present.
Source path of search result after run the run	A recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
Result	The trimmed printed tree of the LST element that the marker is attached to.
Description	The content of the description of the marker.
Recipe that added the search marker	The specific recipe that added the Search marker.

Source files that errored on a recipe

org.openrewrite.table.SourcesFileErrors

The details of all errors produced by a recipe run.

Export after a run

mod study . --last-recipe-run \
  --data-table org.openrewrite.table.SourcesFileErrors

Column	Description
Source path	The file that failed to parse.
Recipe that made changes	The specific recipe that made a change.
Stack trace	The stack trace of the failure.

Recipe performance

org.openrewrite.table.RecipeRunStats

Statistics used in analyzing the performance of recipes.

Export after a run

mod study . --last-recipe-run \
  --data-table org.openrewrite.table.RecipeRunStats

Column	Description
The recipe	The recipe whose stats are being measured both individually and cumulatively.
Source file count	The number of source files the recipe ran over.
Source file changed count	The number of source files which were changed in the recipe run. Includes files created, deleted, and edited.
Cumulative scanning time (ns)	The total time spent across the scanning phase of this recipe.
Max scanning time (ns)	The max time scanning any one source file.
Cumulative edit time (ns)	The total time spent across the editing phase of this recipe.
Max edit time (ns)	The max time editing any one source file.