Rely on existing Sentinel

Author: blacelle

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

@@ -39,9 +39,6 @@
 public final class Formatter implements Serializable, AutoCloseable {
 	private static final long serialVersionUID = 1L;
 
-	// This Sentinel reference may be used where Formatter requires a File, while there is no actual File to format
-	public static final File SENTINEL_NO_FILE_ON_DISK = new File("NO_FILE_ON_DISK.sentinel");
-
 	private LineEnding.Policy lineEndingsPolicy;
 	private Charset encoding;
 	private Path rootDir;
@@ -240,7 +237,7 @@ public String compute(String unix, File file) {
 					unix = LineEnding.toUnix(formatted);
 				}
 			} catch (Throwable e) {
-				if (file == SENTINEL_NO_FILE_ON_DISK) {
+				if (file == FormatterStepImpl.SENTINEL) {
 					exceptionPolicy.handleError(e, step, "");
 				} else {
 					// Path may be forged from a different FileSystem than Filesystem.default

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2023 DiffPlug
+ * Copyright 2016-2021 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -127,7 +127,7 @@ public String apply(String unix, File file) throws Exception {
 
 				@Override
 				public String apply(String unix) throws Exception {
-					return apply(unix, Formatter.SENTINEL_NO_FILE_ON_DISK);
+					return apply(unix, FormatterStepImpl.SENTINEL);
 				}
 			};
 		}
@@ -156,7 +156,7 @@ default String apply(String unix, File file) throws Exception {
 
 		@Override
 		default String apply(String unix) throws Exception {
-			return apply(unix, Formatter.SENTINEL_NO_FILE_ON_DISK);
+			return apply(unix, FormatterStepImpl.SENTINEL);
 		}
 	}
 }

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

@@ -38,7 +38,7 @@ public interface FormatterStep extends Serializable {
 	 *            the content to format, guaranteed to have unix-style newlines ('\n'); never null
 	 * @param file
 	 *            the file which {@code rawUnix} was obtained from; never null. Pass the reference
-	 *            {@code Formatter#SENTINEL_NO_FILE_ON_DISK} if and only if no file is actually associated with {@code rawUnix}
+	 *            {@code FormatterStepImpl#SENTINEL} if and only if no file is actually associated with {@code rawUnix}
 	 * @return the formatted content, guaranteed to only have unix-style newlines; may return null
 	 *         if the formatter step doesn't have any changes to make
 	 * @throws Exception if the formatter step experiences a problem

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

@@ -109,15 +109,18 @@ protected String format(Integer state, String rawUnix, File file) throws Excepti
 			if (formatter == null) {
 				formatter = formatterSupplier.get();
 				if (formatter instanceof FormatterFunc.Closeable) {
-					throw new AssertionError("NeverUpToDate does not support FormatterFunc.Closeable. See https://github.com/diffplug/spotless/pull/284");
+					throw new AssertionError("NeverUpToDate does not support FormatterFunc.Closeable.  See https://github.com/diffplug/spotless/pull/284");
 				}
 			}
 			return formatter.apply(rawUnix, file);
 		}
 	}
 
+	/**This Sentinel reference may be used where Formatter requires a File, while there is no actual File to format */
+	public static final File SENTINEL = new File("");
+
 	static void checkNotSentinel(File file) {
-		if (file == Formatter.SENTINEL_NO_FILE_ON_DISK) {
+		if (file == SENTINEL) {
 			throw new IllegalArgumentException("This step requires the underlying file. If this is a test, use StepHarnessWithFile");
 		}
 	}