Make sure that lint suppression path-filtering is always done using unix paths.

Author: EdgarTwigg

lib/src/main/java/com/diffplug/spotless/LintSuppression.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2024 DiffPlug
+ * Copyright 2024-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,8 +15,11 @@
  */
 package com.diffplug.spotless;
 
+import java.io.File;
 import java.util.Objects;
 
+import javax.annotation.Nullable;
+
 public class LintSuppression implements java.io.Serializable {
 	private static final long serialVersionUID = 1L;
 
@@ -30,6 +33,9 @@ public String getPath() {
 	}
 
 	public void setPath(String path) {
+		if (path.indexOf('\\') != -1) {
+			throw new IllegalArgumentException("Path must use only unix style path separator `/`, this was " + path);
+		}
 		this.path = Objects.requireNonNull(path);
 	}
 
@@ -90,4 +96,20 @@ public String toString() {
 				", code='" + shortCode + '\'' +
 				'}';
 	}
+
+	/**
+	 * Returns the relative path between root and dest, or null if dest is not a
+	 * child of root. Guaranteed to only have unix-separators.
+	 */
+	public static @Nullable String relativizeAsUnix(File root, File dest) {
+		String rootPath = root.getAbsolutePath();
+		String destPath = dest.getAbsolutePath();
+		if (!destPath.startsWith(rootPath)) {
+			return null;
+		} else {
+			String relativized = destPath.substring(rootPath.length());
+			String unixified = relativized.replace('\\', '/');
+			return unixified.startsWith("/") ? unixified.substring(1) : unixified;
+		}
+	}
 }

plugin-gradle/src/main/java/com/diffplug/gradle/spotless/FormatExtension.java

@@ -347,27 +347,12 @@ private final FileCollection parseTargetIsExclude(Object target, boolean isExclu
 	}
 
 	private static void relativizeIfSubdir(List<String> relativePaths, File root, File dest) {
-		String relativized = relativize(root, dest);
+		String relativized = LintSuppression.relativizeAsUnix(root, dest);
 		if (relativized != null) {
 			relativePaths.add(relativized);
 		}
 	}
 
-	/**
-	 * Returns the relative path between root and dest, or null if dest is not a
-	 * child of root.
-	 */
-	static @Nullable String relativize(File root, File dest) {
-		String rootPath = root.getAbsolutePath();
-		String destPath = dest.getAbsolutePath();
-		if (!destPath.startsWith(rootPath)) {
-			return null;
-		} else {
-			String relativized = destPath.substring(rootPath.length());
-			return relativized.startsWith("/") || relativized.startsWith("\\") ? relativized.substring(1) : relativized;
-		}
-	}
-
 	/** The steps that need to be added. */
 	protected final List<FormatterStep> steps = new ArrayList<>();
 

plugin-maven/src/main/java/com/diffplug/spotless/maven/AbstractSpotlessMojo.java

@@ -54,6 +54,7 @@
 import com.diffplug.spotless.Formatter;
 import com.diffplug.spotless.Jvm;
 import com.diffplug.spotless.LineEnding;
+import com.diffplug.spotless.LintState;
 import com.diffplug.spotless.LintSuppression;
 import com.diffplug.spotless.Provisioner;
 import com.diffplug.spotless.generic.LicenseHeaderStep;
@@ -228,7 +229,16 @@ protected List<LintSuppression> getLintSuppressions() {
 		return lintSuppressions;
 	}
 
-	protected abstract void process(String name, Iterable<File> files, Formatter formatter, UpToDateChecker upToDateChecker, List<LintSuppression> lintSuppressions) throws MojoExecutionException;
+	protected abstract void process(String name, Iterable<File> files, Formatter formatter, UpToDateChecker upToDateChecker) throws MojoExecutionException;
+
+	protected LintState calculateLintState(Formatter formatter, File file) throws IOException {
+		String relativePath = LintSuppression.relativizeAsUnix(baseDir, file);
+		if (relativePath == null) {
+			// File is not within baseDir, use absolute path as fallback
+			relativePath = file.getAbsolutePath();
+		}
+		return LintState.of(formatter, file).withRemovedSuppressions(formatter, relativePath, lintSuppressions);
+	}
 
 	private static final int MINIMUM_JRE = 11;
 
@@ -261,7 +271,7 @@ public final void execute() throws MojoExecutionException {
 			for (FormatterFactory factory : formattersHolder.openFormatters.keySet()) {
 				Formatter formatter = formattersHolder.openFormatters.get(factory);
 				Iterable<File> files = formattersHolder.factoryToFiles.get(factory).get();
-				process(formattersHolder.nameFor(factory), files, formatter, upToDateChecker, getLintSuppressions());
+				process(formattersHolder.nameFor(factory), files, formatter, upToDateChecker);
 			}
 		} catch (PluginException e) {
 			throw e.asMojoExecutionException();
@@ -424,19 +434,4 @@ private UpToDateChecker createUpToDateChecker(Iterable<Formatter> formatters) {
 		}
 		return UpToDateChecker.wrapWithBuildContext(checker, buildContext);
 	}
-
-	/**
-	 * Returns the relative path between root and dest, or null if dest is not a
-	 * child of root.
-	 */
-	static String relativize(File root, File dest) {
-		String rootPath = root.getAbsolutePath();
-		String destPath = dest.getAbsolutePath();
-		if (!destPath.startsWith(rootPath)) {
-			return null;
-		} else {
-			String relativized = destPath.substring(rootPath.length());
-			return relativized.startsWith("/") || relativized.startsWith("\\") ? relativized.substring(1) : relativized;
-		}
-	}
 }

plugin-maven/src/main/java/com/diffplug/spotless/maven/SpotlessApplyMojo.java

@@ -45,7 +45,7 @@ public class SpotlessApplyMojo extends AbstractSpotlessMojo {
 	private boolean spotlessIdeHookUseStdOut;
 
 	@Override
-	protected void process(String name, Iterable<File> files, Formatter formatter, UpToDateChecker upToDateChecker, List<LintSuppression> lintSuppressions) throws MojoExecutionException {
+	protected void process(String name, Iterable<File> files, Formatter formatter, UpToDateChecker upToDateChecker) throws MojoExecutionException {
 		if (isIdeHook()) {
 			IdeHook.performHook(files, formatter, spotlessIdeHook, spotlessIdeHookUseStdIn, spotlessIdeHookUseStdOut);
 			return;
@@ -63,12 +63,7 @@ protected void process(String name, Iterable<File> files, Formatter formatter, U
 			}
 
 			try {
-				String relativePath = relativize(baseDir, file);
-				if (relativePath == null) {
-					// File is not within baseDir, use absolute path as fallback
-					relativePath = file.getAbsolutePath();
-				}
-				LintState lintState = LintState.of(formatter, file).withRemovedSuppressions(formatter, relativePath, lintSuppressions);
+				LintState lintState = super.calculateLintState(formatter, file);
 				boolean hasDirtyState = !lintState.getDirtyState().isClean() && !lintState.getDirtyState().didNotConverge();
 				boolean hasUnsuppressedLints = lintState.isHasLints();
 
@@ -93,6 +88,7 @@ protected void process(String name, Iterable<File> files, Formatter formatter, U
 					for (Map.Entry<String, List<com.diffplug.spotless.Lint>> stepEntry : lintState.getLintsByStep(formatter).entrySet()) {
 						String stepName = stepEntry.getKey();
 						for (com.diffplug.spotless.Lint lint : stepEntry.getValue()) {
+							String relativePath = LintSuppression.relativizeAsUnix(baseDir, file);
 							message.append("\n  ").append(relativePath).append(":");
 							lint.addWarningMessageTo(message, stepName, true);
 						}

plugin-maven/src/main/java/com/diffplug/spotless/maven/SpotlessCheckMojo.java

@@ -29,7 +29,6 @@
 
 import com.diffplug.spotless.Formatter;
 import com.diffplug.spotless.LintState;
-import com.diffplug.spotless.LintSuppression;
 import com.diffplug.spotless.extra.integration.DiffMessageFormatter;
 import com.diffplug.spotless.maven.incremental.UpToDateChecker;
 
@@ -65,7 +64,7 @@ public int getSeverity() {
 	private MessageSeverity m2eIncrementalBuildMessageSeverity;
 
 	@Override
-	protected void process(String name, Iterable<File> files, Formatter formatter, UpToDateChecker upToDateChecker, List<LintSuppression> lintSuppressions) throws MojoExecutionException {
+	protected void process(String name, Iterable<File> files, Formatter formatter, UpToDateChecker upToDateChecker) throws MojoExecutionException {
 		ImpactedFilesTracker counter = new ImpactedFilesTracker();
 
 		List<File> problemFiles = new ArrayList<>();
@@ -80,12 +79,7 @@ protected void process(String name, Iterable<File> files, Formatter formatter, U
 			}
 			buildContext.removeMessages(file);
 			try {
-				String relativePath = relativize(baseDir, file);
-				if (relativePath == null) {
-					// File is not within baseDir, use absolute path as fallback
-					relativePath = file.getAbsolutePath();
-				}
-				LintState lintState = LintState.of(formatter, file).withRemovedSuppressions(formatter, relativePath, lintSuppressions);
+				LintState lintState = super.calculateLintState(formatter, file);
 				boolean hasDirtyState = !lintState.getDirtyState().isClean() && !lintState.getDirtyState().didNotConverge();
 				boolean hasUnsuppressedLints = lintState.isHasLints();