diffplug · nchaugen · Feb 23, 2026 · Feb 23, 2026
diff --git a/CHANGES.md b/CHANGES.md
@@ -10,6 +10,8 @@ This document is intended for Spotless developers.
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Added
+- Add `tabletest-formatter` support for Java and Kotlin. ([#2860](https://github.com/diffplug/spotless/pull/2860))
 ### Fixed
 - Fix the ability to specify a wildcard version (`*`) for external formatter executables, which did not work. ([#2848](https://github.com/diffplug/spotless/pull/2848))
 

diff --git a/lib/build.gradle b/lib/build.gradle
@@ -24,6 +24,7 @@ def NEEDS_GLUE = [
 	'palantirJavaFormat',
 	'scalafmt',
 	'sortPom',
+	'tableTestFormatter',
 	'zjsonPatch',
 ]
 for (glue in NEEDS_GLUE) {
@@ -122,6 +123,8 @@ dependencies {
 	// sortPom
 	sortPomCompileOnly 'com.github.ekryd.sortpom:sortpom-sorter:4.0.0'
 	sortPomCompileOnly 'org.slf4j:slf4j-api:2.0.17'
+	// tableTestFormatter
+	tableTestFormatterCompileOnly 'org.tabletest:tabletest-formatter-core:1.0.1'
 	// zjsonPatch
 	zjsonPatchCompileOnly 'com.flipkart.zjsonpatch:zjsonpatch:0.4.16'
 }

diff --git a/lib/src/main/java/com/diffplug/spotless/java/TableTestFormatterStep.java b/lib/src/main/java/com/diffplug/spotless/java/TableTestFormatterStep.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2026 DiffPlug
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.diffplug.spotless.java;
+
+import java.io.Serial;
+import java.io.Serializable;
+import java.lang.reflect.Constructor;
+import java.util.Objects;
+
+import com.diffplug.spotless.FormatterFunc;
+import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.JarState;
+import com.diffplug.spotless.Provisioner;
+
+/**
+ * Formats {@code @TableTest} annotation tables in Java and Kotlin source files.
+ * Configuration is read from {@code .editorconfig} files.
+ */
+public final class TableTestFormatterStep implements Serializable {
+	@Serial
+	private static final long serialVersionUID = 1L;
+	private static final String NAME = "tableTestFormatter";
+	private static final String MAVEN_COORDINATE = "org.tabletest:tabletest-formatter-core:";
+	private static final String DEFAULT_VERSION = "1.0.1";
+
+	private final JarState.Promised jarState;
+	private final String version;
+
+	private TableTestFormatterStep(JarState.Promised jarState, String version) {
+		this.jarState = jarState;
+		this.version = version;
+	}
+
+	/** Creates a step which formats {@code @TableTest} tables using the default version. */
+	public static FormatterStep create(Provisioner provisioner) {
+		return create(defaultVersion(), provisioner);
+	}
+
+	/** Creates a step which formats {@code @TableTest} tables using the given version. */
+	public static FormatterStep create(String version, Provisioner provisioner) {
+		Objects.requireNonNull(version, "version");
+		Objects.requireNonNull(provisioner, "provisioner");
+		return FormatterStep.create(NAME,
+				new TableTestFormatterStep(JarState.promise(() -> JarState.from(MAVEN_COORDINATE + version, provisioner)), version),
+				TableTestFormatterStep::equalityState,
+				State::createFormat);
+	}
+
+	/** Get default formatter version. */
+	public static String defaultVersion() {
+		return DEFAULT_VERSION;
+	}
+
+	private State equalityState() {
+		return new State(jarState.get(), version);
+	}
+
+	private static final class State implements Serializable {
+		@Serial
+		private static final long serialVersionUID = 1L;
+
+		private final JarState jarState;
+		private final String version;
+
+		State(JarState jarState, String version) {
+			this.jarState = jarState;
+			this.version = version;
+		}
+
+		FormatterFunc createFormat() throws Exception {
+			ClassLoader classLoader = jarState.getClassLoader();
+			Class<?> formatterClazz = classLoader.loadClass("com.diffplug.spotless.glue.java.TableTestFormatterFunc");
+			Constructor<?> constructor = formatterClazz.getConstructor();
+			return (FormatterFunc.NeedsFile) constructor.newInstance();
+		}
+	}
+}
diff --git a/lib/src/tableTestFormatter/java/com/diffplug/spotless/glue/java/TableTestFormatterFunc.java b/lib/src/tableTestFormatter/java/com/diffplug/spotless/glue/java/TableTestFormatterFunc.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2026 DiffPlug
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.diffplug.spotless.glue.java;
+
+import java.io.File;
+
+import org.tabletest.formatter.config.Config;
+import org.tabletest.formatter.config.EditorConfigProvider;
+import org.tabletest.formatter.core.SourceFileFormatter;
+import org.tabletest.formatter.core.TableTestFormatter;
+
+import com.diffplug.spotless.FormatterFunc;
+
+/**
+ * Formats {@code @TableTest} annotation tables in Java and Kotlin source files.
+ */
+public class TableTestFormatterFunc implements FormatterFunc.NeedsFile {
+
+	private static final EditorConfigProvider CONFIG_PROVIDER = new EditorConfigProvider();
+
+	private final TableTestFormatter tableFormatter = new TableTestFormatter();
+	private final SourceFileFormatter sourceFormatter = new SourceFileFormatter();
+
+	@Override
+	public String applyWithFile(String unix, File file) throws Exception {
+		String fileName = file.getName();
+
+		if (fileName.endsWith(".java") || fileName.endsWith(".kt")) {
+			Config config = CONFIG_PROVIDER.lookupConfig(file.toPath(), Config.SPACES_4);
+			String formatted = sourceFormatter.format(unix, config);
+			return formatted.equals(unix) ? unix : formatted;
+		}
+
+		return unix;
+	}
+}
diff --git a/plugin-gradle/CHANGES.md b/plugin-gradle/CHANGES.md
@@ -3,6 +3,8 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `3.27.0`).
 
 ## [Unreleased]
+### Added
+- Add `tabletest-formatter` support for Java and Kotlin. ([#2860](https://github.com/diffplug/spotless/pull/2860))
 ### Fixed
 - Fix the ability to specify a wildcard version (`*`) for external formatter executables, which did not work. ([#2848](https://github.com/diffplug/spotless/pull/2848))
 

diff --git a/plugin-gradle/README.md b/plugin-gradle/README.md
@@ -56,9 +56,9 @@ Spotless supports all of Gradle's built-in performance features (incremental bui
   - [Git hook (optional)](#git-hook)
   - [Linting](#linting)
 - **Languages**
-  - [Java](#java) ([google-java-format](#google-java-format), [eclipse jdt](#eclipse-jdt), [clang-format](#clang-format), [prettier](#prettier), [palantir-java-format](#palantir-java-format), [formatAnnotations](#formatAnnotations), [cleanthat](#cleanthat), [IntelliJ IDEA](#intellij-idea))
+  - [Java](#java) ([google-java-format](#google-java-format), [eclipse jdt](#eclipse-jdt), [clang-format](#clang-format), [prettier](#prettier), [palantir-java-format](#palantir-java-format), [formatAnnotations](#formatAnnotations), [cleanthat](#cleanthat), [tabletest-formatter](#tabletest-formatter), [IntelliJ IDEA](#intellij-idea))
   - [Groovy](#groovy) ([eclipse groovy](#eclipse-groovy))
-  - [Kotlin](#kotlin) ([ktfmt](#ktfmt), [ktlint](#ktlint), [diktat](#diktat), [prettier](#prettier))
+  - [Kotlin](#kotlin) ([ktfmt](#ktfmt), [ktlint](#ktlint), [diktat](#diktat), [tabletest-formatter](#tabletest-formatter-1), [prettier](#prettier))
   - [Scala](#scala) ([scalafmt](#scalafmt))
   - [C/C++](#cc) ([clang-format](#clang-format), [eclipse cdt](#eclipse-cdt))
   - [Protobuf](#protobuf) ([buf](#buf), [clang-format](#clang-format))
@@ -220,6 +220,8 @@ spotless {
     clangFormat()        // has its own section below
     idea()               // has its own section below
 
+    tableTestFormatter() // has its own section below
+
     formatAnnotations()  // fixes formatting of type annotations, see below
 
     licenseHeader '/* (C) $YEAR */' // or licenseHeaderFile
@@ -428,6 +430,17 @@ spotless {
       .includeDraft(false)                                 // You may exclude draft mutators (from Composite ones)
 ```
 
+### tabletest-formatter
+
+[homepage](https://github.com/nchaugen/tabletest-formatter). [changelog](https://github.com/nchaugen/tabletest-formatter/releases). Formats [`@TableTest`](https://github.com/nchaugen/tabletest) tables in Java source files. All configuration is read from `.editorconfig` files.
+
+```gradle
+spotless {
+  java {
+    tableTestFormatter()
+    // optional: you can specify a specific version
+    tableTestFormatter('1.0.1')
+```
 
 <a name="applying-to-groovy-source"></a>
 
@@ -510,6 +523,7 @@ spotless { // if you are using build.gradle.kts, instead of 'spotless {' use:
     ktlint()   // has its own section below
     diktat()   // has its own section below
     prettier() // has its own section below
+    tableTestFormatter() // has its own section below
     licenseHeader '/* (C)$YEAR */' // or licenseHeaderFile
   }
   kotlinGradle {
@@ -593,6 +607,18 @@ spotless {
     diktat('1.0.1').configFile("full/path/to/diktat-analysis.yml")
 ```
 
+### tabletest-formatter
+
+[homepage](https://github.com/nchaugen/tabletest-formatter). [changelog](https://github.com/nchaugen/tabletest-formatter/releases). Formats [`@TableTest`](https://github.com/nchaugen/tabletest) tables in Kotlin source files. All configuration is read from `.editorconfig` files.
+
+```kotlin
+spotless {
+  kotlin {
+    tableTestFormatter()
+    // optional: you can specify a specific version
+    tableTestFormatter('1.0.1')
+```
+
 <a name="applying-scalafmt-to-scala-files"></a>
 
 ## Scala

diff --git a/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/BaseKotlinExtension.java b/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/BaseKotlinExtension.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2023-2025 DiffPlug
+ * Copyright 2023-2026 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -29,6 +29,7 @@
 import com.diffplug.common.collect.ImmutableSortedMap;
 import com.diffplug.spotless.FileSignature;
 import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.java.TableTestFormatterStep;
 import com.diffplug.spotless.kotlin.DiktatStep;
 import com.diffplug.spotless.kotlin.KtLintStep;
 import com.diffplug.spotless.kotlin.KtfmtStep;
@@ -69,6 +70,30 @@ public KtfmtConfig ktfmt(String version) {
 		return new KtfmtConfig(version);
 	}
 
+	/** Formats {@code @TableTest} annotation tables using <a href="https://github.com/nchaugen/tabletest-formatter">tabletest-formatter</a>. */
+	public TableTestFormatterConfig tableTestFormatter() {
+		return tableTestFormatter(TableTestFormatterStep.defaultVersion());
+	}
+
+	/** Formats {@code @TableTest} annotation tables using the given version of tabletest-formatter. */
+	public TableTestFormatterConfig tableTestFormatter(String version) {
+		Objects.requireNonNull(version);
+		return new TableTestFormatterConfig(version);
+	}
+
+	public final class TableTestFormatterConfig {
+		final String version;
+
+		TableTestFormatterConfig(String version) {
+			this.version = Objects.requireNonNull(version);
+			addStep(createStep());
+		}
+
+		private FormatterStep createStep() {
+			return TableTestFormatterStep.create(version, provisioner());
+		}
+	}
+
 	protected abstract boolean isScript();
 
 	public final class DiktatConfig {

diff --git a/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/JavaExtension.java b/plugin-gradle/src/main/java/com/diffplug/gradle/spotless/JavaExtension.java
@@ -47,6 +47,7 @@
 import com.diffplug.spotless.java.ImportOrderStep;
 import com.diffplug.spotless.java.PalantirJavaFormatStep;
 import com.diffplug.spotless.java.RemoveUnusedImportsStep;
+import com.diffplug.spotless.java.TableTestFormatterStep;
 
 public class JavaExtension extends FormatExtension implements HasBuiltinDelimiterForLicense, JvmLang {
 	static final String NAME = "java";
@@ -507,6 +508,30 @@ private FormatterStep createStep() {
 		}
 	}
 
+	/** Formats {@code @TableTest} annotation tables using <a href="https://github.com/nchaugen/tabletest-formatter">tabletest-formatter</a>. */
+	public TableTestFormatterConfig tableTestFormatter() {
+		return tableTestFormatter(TableTestFormatterStep.defaultVersion());
+	}
+
+	/** Formats {@code @TableTest} annotation tables using <a href="https://github.com/nchaugen/tabletest-formatter">tabletest-formatter</a>. */
+	public TableTestFormatterConfig tableTestFormatter(String version) {
+		Objects.requireNonNull(version);
+		return new TableTestFormatterConfig(version);
+	}
+
+	public class TableTestFormatterConfig {
+		final String version;
+
+		TableTestFormatterConfig(String version) {
+			this.version = Objects.requireNonNull(version);
+			addStep(createStep());
+		}
+
+		private FormatterStep createStep() {
+			return TableTestFormatterStep.create(version, provisioner());
+		}
+	}
+
 	/** If the user hasn't specified the files yet, we'll assume he/she means all of the java files. */
 	@Override
 	protected void setupTask(SpotlessTask task) {

diff --git a/plugin-maven/CHANGES.md b/plugin-maven/CHANGES.md
@@ -3,6 +3,8 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Added
+- Add `tabletest-formatter` support for Java and Kotlin. ([#2860](https://github.com/diffplug/spotless/pull/2860))
 ### Fixed
 - Fix the ability to specify a wildcard version (`*`) for external formatter executables, which did not work. ([#2848](https://github.com/diffplug/spotless/pull/2848))
 

diff --git a/plugin-maven/README.md b/plugin-maven/README.md
@@ -40,9 +40,9 @@ user@machine repo % mvn spotless:check
   - [Git hook (optional)](#git-hook)
   - [Binding to maven phase](#binding-to-maven-phase)
 - **Languages**
-  - [Java](#java) ([google-java-format](#google-java-format), [eclipse jdt](#eclipse-jdt), [prettier](#prettier), [palantir-java-format](#palantir-java-format), [formatAnnotations](#formatAnnotations), [cleanthat](#cleanthat), [IntelliJ IDEA](#intellij-idea))
+  - [Java](#java) ([google-java-format](#google-java-format), [eclipse jdt](#eclipse-jdt), [prettier](#prettier), [palantir-java-format](#palantir-java-format), [formatAnnotations](#formatAnnotations), [cleanthat](#cleanthat), [tabletest-formatter](#tabletest-formatter), [IntelliJ IDEA](#intellij-idea))
   - [Groovy](#groovy) ([eclipse groovy](#eclipse-groovy))
-  - [Kotlin](#kotlin) ([ktfmt](#ktfmt), [ktlint](#ktlint), [diktat](#diktat), [prettier](#prettier))
+  - [Kotlin](#kotlin) ([ktfmt](#ktfmt), [ktlint](#ktlint), [diktat](#diktat), [tabletest-formatter](#tabletest-formatter-1), [prettier](#prettier))
   - [Scala](#scala) ([scalafmt](#scalafmt))
   - [C/C++](#cc) ([eclipse cdt](#eclipse-cdt), [clang-format](#clang-format))
   - [Python](#python) ([black](#black))
@@ -216,6 +216,8 @@ any other maven phase (i.e. compile) then it can be configured as below;
     <prettier />         <!-- has its own section below -->
     <idea />             <!-- has its own section below -->
 
+    <tableTestFormatter /> <!-- has its own section below -->
+
     <importOrder /> <!-- standard import order -->
     <importOrder>  <!-- or a custom ordering -->
       <wildcardsLast>false</wildcardsLast> <!-- Optional, default false. Sort wildcard import after specific imports -->
@@ -399,6 +401,16 @@ These mechanisms already exist for the Gradle plugin.
 </cleanthat>
 ```
 
+### tabletest-formatter
+
+[homepage](https://github.com/nchaugen/tabletest-formatter). [changelog](https://github.com/nchaugen/tabletest-formatter/releases). [code](https://github.com/diffplug/spotless/blob/main/plugin-maven/src/main/java/com/diffplug/spotless/maven/java/TableTestFormatter.java). Formats [`@TableTest`](https://github.com/nchaugen/tabletest) tables in Java source files. All configuration is read from `.editorconfig` files.
+
+```xml
+<tableTestFormatter>
+  <version>1.0.1</version> <!-- optional -->
+</tableTestFormatter>
+```
+
 ## Groovy
 
 [code](https://github.com/diffplug/spotless/blob/main/plugin-maven/src/main/java/com/diffplug/spotless/maven/groovy/Groovy.java). [available steps](https://github.com/diffplug/spotless/tree/main/plugin-maven/src/main/java/com/diffplug/spotless/maven/groovy).
@@ -462,6 +474,8 @@ Groovy-Eclipse formatting errors/warnings lead per default to a build failure. T
     <diktat />   <!-- has its own section below -->
     <prettier /> <!-- has its own section below -->
 
+    <tableTestFormatter /> <!-- has its own section below -->
+
     <licenseHeader>
       <content>/* (C)$YEAR */</content>  <!-- or <file>${project.basedir}/license-header</file> -->
     </licenseHeader>
@@ -523,6 +537,16 @@ Additionally, `editorConfigOverride` options will override what's supplied in `.
 </diktat>
 ```
 
+### tabletest-formatter
+
+[homepage](https://github.com/nchaugen/tabletest-formatter). [changelog](https://github.com/nchaugen/tabletest-formatter/releases). [code](https://github.com/diffplug/spotless/blob/main/plugin-maven/src/main/java/com/diffplug/spotless/maven/kotlin/TableTestFormatter.java). Formats [`@TableTest`](https://github.com/nchaugen/tabletest) tables in Kotlin source files. All configuration is read from `.editorconfig` files.
+
+```xml
+<tableTestFormatter>
+  <version>1.0.1</version> <!-- optional -->
+</tableTestFormatter>
+```
+
 <a name="applying-to-scala-source"></a>
 
 ## Scala