feat: add eclipse wtp formatter (#12)

Author: simschla

.idea/compiler.xml

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Added formatter [`eclipse-wtp`](https://github.com/diffplug/spotless/tree/main/plugin-gradle#eclipse-web-tools-platform)
+
 ## [0.2.0] - 2025-07-31
 
 ### Fixed

CHANGELOG.md

@@ -154,6 +154,7 @@ or apply the formatting to the files.
 Available formatting steps:
   clang-format           Runs clang-format
   clean-that             CleanThat enables automatic refactoring of Java code.
+  eclipse-wtp            Runs Eclipse WTP formatter (4.21.0)
   format-annotations     Corrects line break formatting of type annotations in
                            java files.
   google-java-format     Runs google java format
@@ -186,6 +187,7 @@ Spotless CLI supports the following formatter steps in alphabetical order:
 
 - [clang-format](#clang-format)
 - [clean-that](#clean-that)
+- [eclipse-wtp](#eclipse-wtp)
 - [format-annotations](#format-annotations)
 - [google-java-format](#google-java-format)
 - [license-header](#license-header)
@@ -311,6 +313,74 @@ Example usage:
 spotless --target '**/src/**/*.java' clean-that --exclude-mutator=StreamAnyMatch
 ```
 
+### eclipse-wtp
+
+<!---freshmark eclipsewtpshields
+output = [
+  link(shield('spotless eclipse wtp version', 'spotless-eclipse-wtp', '{{libs.versions.native.include.spotlessEclipseWtp}}', 'blue'), 'https://central.sonatype.com/artifact/com.diffplug.spotless/spotless-eclipse-wtp/{{libs.versions.native.include.spotlessEclipseWtp}}'),
+  link(shield('eclipse wtp version', 'eclipse-wtp-formatter', '{{libs.versions.native.include.spotlessEclipseWtpFormatter}}', 'blue'), 'https://github.com/diffplug/spotless/blob/main/lib-extra/src/main/resources/com/diffplug/spotless/extra/eclipse_wtp_formatter/v{{libs.versions.native.include.spotlessEclipseWtpFormatter}}'),
+  ].join('\n')
+-->
+
+[![spotless eclipse wtp version](https://img.shields.io/badge/spotless--eclipse--wtp-3.23.0-blue.svg)](https://central.sonatype.com/artifact/com.diffplug.spotless/spotless-eclipse-wtp/3.23.0)
+[![eclipse wtp version](https://img.shields.io/badge/eclipse--wtp--formatter-4.21.0-blue.svg)](https://github.com/diffplug/spotless/blob/main/lib-extra/src/main/resources/com/diffplug/spotless/extra/eclipse_wtp_formatter/v4.21.0)
+
+<!---freshmark /eclipsewtpshields -->
+
+The [eclipse web tools platform (WTP)](https://projects.eclipse.org/projects/webtools) formatter is a formatter for web files such as HTML, CSS, JavaScript, JSON, XML and XHTML.
+
+It comes with reasonable defaults but can be configured using configuration files. For details see the [spotless documentation](https://github.com/diffplug/spotless/tree/main/plugin-gradle#eclipse-web-tools-platform).
+
+To see usage instructions for the eclipse-wtp formatter, run: `spotless eclipse-wtp --help`
+
+<!---freshmark usage_eclipse_wtp
+output =
+   '```\n' +
+   {{usage.eclipse-wtp.array}}.join('\n') +
+    '\n```';
+-->
+
+```
+Usage: spotless eclipse-wtp [-hV] [-f]... [-t=<type>]
+Runs Eclipse WTP formatter (4.21.0)
+  -f, --config-file   The path to the Eclipse WTP configuration file. For
+                        supported config file options see spotless
+                        documentation (additional info links).
+  -h, --help          Show this help message and exit.
+  -t, --type=<type>   The type of the Eclipse WTP formatter. If not provided,
+                        the type will be guessed based on the first few files
+                        we find. If that does not work, we fail the formatting
+                        run.
+                      One of: CSS, HTML, JS, JSON, XML, XHTML
+  -V, --version       Print version information and exit.
+
+✅ This step supports the following file types:
+   * css
+   * html
+   * js
+   * json
+   * xml
+   * xhtml
+
+🌎 Additional info:
+   * https://github.com/diffplug/spotless/tree/main/plugin-gradle#eclipse-web-to
+    ols-platform
+
+   * https://projects.eclipse.org/projects/webtools
+```
+
+<!---freshmark /usage_eclipse_wtp -->
+
+Example usage:
+
+```shell
+# format all js files using (multiple) project-specific configuration files
+# for details regarding the configuration files see the spotless documentation
+spotless --target '**/*.js' eclipse-wtp --type js --config-file spotless.xml.prefs --config-file spotless.common.properties
+# or use defaults and infer type from files
+spotless --target '**/*.css' eclipse-wtp
+```
+
 ### format-annotations
 
 In Java, type annotations should be on the same line as the type that they qualify. This formatter fixes this for you.

README.md

@@ -1,4 +1,6 @@
 import com.diffplug.spotless.cli.picocli.usage.GenerateUsagePropertiesTask
+import com.diffplug.spotless.extra.wtp.EclipseWtpFormatterStep
+import org.gradle.plugins.ide.eclipse.model.EclipseWtp
 
 plugins {
 	id 'buildlogic.picocli-conventions'
@@ -9,6 +11,7 @@ plugins {
 
 version = rootProject.version
 
+
 dependencies {
 	testImplementation project(':testlib')
 	implementation libs.bundles.spotless.libs
@@ -17,6 +20,19 @@ dependencies {
 	// these are fixed versions of the otherwise dynamic dependencies for spotless
 	// this is necessary to allow for native compilation where reflective access to dynamic jars is not possible
 	implementation libs.bundles.native.includes
+
+	// Eclipse WTP formatter used a custom lockfile to ensure the formatter has the
+	// correct version of all its libraries
+	def resourceName = "/com/diffplug/spotless/extra/eclipse_wtp_formatter/v4.21.0.lockfile"
+	logger.debug("reading eclipse wtp resource: " + resourceName)
+	EclipseWtpFormatterStep.getResource(resourceName)
+			.readLines()
+			.findAll { !it.startsWith('#')} // filter out comments
+			.each {
+				implementation("${it}") {
+					transitive=false
+				}
+			}
 }
 
 application {
@@ -35,7 +51,7 @@ gradle.taskGraph.whenReady { TaskExecutionGraph graph ->
 }
 
 tasks.withType(Test).configureEach {
-	if (it.name == 'test' || it.name == 'testNpm') {
+	if (it.name == 'test' || it.name == 'testNpm' || it.name == 'testSeparateJvm') {
 		it.outputs.dir(nativeCompileMetaDir)
 		if (project.hasProperty('agent')) {
 			it.inputs.property('agent', project.property('agent')) // make sure to re-run tests if agent changes

app/build.gradle

@@ -45,6 +45,7 @@
 import com.diffplug.spotless.cli.logging.output.Output;
 import com.diffplug.spotless.cli.steps.ClangFormat;
 import com.diffplug.spotless.cli.steps.CleanThat;
+import com.diffplug.spotless.cli.steps.EclipseWtp;
 import com.diffplug.spotless.cli.steps.FormatAnnotations;
 import com.diffplug.spotless.cli.steps.GoogleJavaFormat;
 import com.diffplug.spotless.cli.steps.LicenseHeader;
@@ -97,6 +98,7 @@
         subcommands = {
             ClangFormat.class,
             CleanThat.class,
+            EclipseWtp.class,
             FormatAnnotations.class,
             GoogleJavaFormat.class,
             LicenseHeader.class,

app/src/main/java/com/diffplug/spotless/cli/SpotlessCLI.java

@@ -0,0 +1,122 @@
+/*
+ * Copyright 2025 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.cli.steps;
+
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Locale;
+import java.util.function.Supplier;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.cli.core.SpotlessActionContext;
+import com.diffplug.spotless.cli.core.TargetFileTypeInferer;
+import com.diffplug.spotless.cli.help.AdditionalInfoLinks;
+import com.diffplug.spotless.cli.help.OptionConstants;
+import com.diffplug.spotless.cli.help.SupportedFileTypes;
+import com.diffplug.spotless.extra.EclipseBasedStepBuilder;
+import com.diffplug.spotless.extra.wtp.EclipseWtpFormatterStep;
+
+import picocli.CommandLine;
+
+@CommandLine.Command(
+        name = "eclipse-wtp",
+        description = "Runs Eclipse WTP formatter (" + EclipseWtp.ECLIPSE_WTP_VERSION + ")")
+@SupportedFileTypes({"css", "html", "js", "json", "xml", "xhtml"})
+@AdditionalInfoLinks({
+    "https://github.com/diffplug/spotless/tree/main/plugin-gradle#eclipse-web-tools-platform",
+    "https://projects.eclipse.org/projects/webtools"
+})
+public class EclipseWtp extends SpotlessFormatterStep {
+
+    public static final String ECLIPSE_WTP_VERSION = "4.21.0"; // TODO we need to slurp in the lock file also
+
+    @CommandLine.Option(
+            names = {"-f", "--config-file"},
+            arity = "0",
+            description = "The path to the Eclipse WTP configuration file. "
+                    + "For supported config file options see spotless documentation (additional info links).")
+    List<Path> configFiles;
+
+    @CommandLine.Option(
+            names = {"-t", "--type"},
+            description =
+                    "The type of the Eclipse WTP formatter. If not provided, the type will be guessed based on the first few files we find. If that does not work, we fail the formatting run."
+                            + OptionConstants.VALID_VALUES_SUFFIX)
+    Type type;
+
+    public enum Type {
+        CSS(EclipseWtpFormatterStep.CSS),
+        HTML(EclipseWtpFormatterStep.HTML),
+        JS(EclipseWtpFormatterStep.JS),
+        JSON(EclipseWtpFormatterStep.JSON),
+        XML(EclipseWtpFormatterStep.XML),
+        XHTML(EclipseWtpFormatterStep.HTML); // XHTML is treated as HTML in Eclipse WTP
+
+        private final EclipseWtpFormatterStep backendEclipseWtpType;
+
+        Type(EclipseWtpFormatterStep backendEclipseWtpType) {
+            this.backendEclipseWtpType = backendEclipseWtpType;
+        }
+
+        public @NotNull EclipseWtpFormatterStep toEclipseWtpType() {
+            return this.backendEclipseWtpType;
+        }
+
+        public static @Nullable Type fromTargetFileType(@NotNull TargetFileTypeInferer.TargetFileType targetFileType) {
+            return switch (targetFileType.fileExtension().toLowerCase(Locale.getDefault())) {
+                case "css" -> CSS;
+                case "html", "htm" -> HTML;
+                case "js" -> JS;
+                case "json" -> JSON;
+                case "xml" -> XML;
+                case "xhtml" -> XHTML;
+                default -> null;
+            };
+        }
+    }
+
+    @Override
+    public @NotNull List<FormatterStep> prepareFormatterSteps(SpotlessActionContext context) {
+        EclipseWtpFormatterStep wtpType = type(context::targetFileType).toEclipseWtpType();
+        EclipseBasedStepBuilder builder = wtpType.createBuilder(context.provisioner());
+        builder.setVersion(ECLIPSE_WTP_VERSION);
+        if (configFiles != null && !configFiles.isEmpty()) {
+            builder.setPreferences(configFiles.stream()
+                    .map(context::resolvePath)
+                    .map(Path::toFile)
+                    .toList());
+        }
+        return List.of(builder.build());
+    }
+
+    private Type type(Supplier<TargetFileTypeInferer.TargetFileType> targetFileTypeSupplier) {
+        if (type != null) {
+            return type;
+        }
+        // try type inferring
+        TargetFileTypeInferer.TargetFileType targetFileType = targetFileTypeSupplier.get();
+        Type inferredType = Type.fromTargetFileType(targetFileType);
+        if (inferredType != null) {
+            return inferredType;
+        } else {
+            throw new IllegalArgumentException("Could not infer Eclipse WTP type from target file type: "
+                    + targetFileType.fileExtension() + " - workaround by specifying the --type option.");
+        }
+    }
+}

app/src/main/java/com/diffplug/spotless/cli/steps/EclipseWtp.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2025 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.cli.steps;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.parallel.Isolated;
+
+import com.diffplug.spotless.tag.CliNativeTest;
+import com.diffplug.spotless.tag.CliProcessTest;
+import com.diffplug.spotless.tag.SeparateJvmTest;
+
+@Isolated
+@SeparateJvmTest
+@CliNativeTest
+@CliProcessTest
+public class EclipseWtpCssTest extends EclipseWtpTestBase {
+
+    @Test
+    void itSupportsFormattingCssFileType() {
+        String fileName = runEclipseWtpWithType(EclipseWtp.Type.CSS, "body {\n" + "a: v;   b:   \n" + "v;\n" + "}  \n");
+        selfie().expectResource(fileName).toMatchDisk();
+    }
+
+    @Test
+    void itInfersCssFileTypeFromFileExtension() {
+        String fileName = runEclipseWtpWithTypeInferred("css", "body {\n" + "a: v;   b:   \n" + "v;\n" + "}  \n");
+        selfie().expectResource(fileName).toMatchDisk();
+    }
+}

app/src/test/java/com/diffplug/spotless/cli/steps/EclipseWtpCssTest.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2025 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.cli.steps;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.parallel.Isolated;
+
+import com.diffplug.spotless.tag.CliNativeTest;
+import com.diffplug.spotless.tag.CliProcessTest;
+import com.diffplug.spotless.tag.SeparateJvmTest;
+
+@Isolated
+@SeparateJvmTest
+@CliNativeTest
+@CliProcessTest
+public class EclipseWtpCssWithConfigTest extends EclipseWtpTestBase {
+
+    @Test
+    void itUsesConfigurationFile() {
+        String fileName = runEclipseWtpWithTypeAndConfigFile(
+                EclipseWtp.Type.CSS,
+                "body {\n" + "a: v;   b:   \n" + "v;\n" + "}  \n",
+                "org.eclipse.wst.css.core.prefs");
+        selfie().expectResource(fileName).toMatchDisk();
+    }
+}