Move NeverUpToDateStep out of lib and into testlib only.

Author: nedtwigg

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

@@ -151,8 +151,8 @@ static <RoundtripState extends Serializable, EqualityState extends Serializable>
 	static <State extends Serializable> FormatterStep createLazy(
 			String name,
 			ThrowingEx.Supplier<State> stateSupplier,
-			ThrowingEx.Function<State, FormatterFunc> stateToFormatter) {
-		return new FormatterStepImpl.Standard<>(name, stateSupplier, stateToFormatter);
+			SerializedFunction<State, FormatterFunc> stateToFormatter) {
+		return createLazy(name, stateSupplier, SerializedFunction.identity(), stateToFormatter);
 	}
 
 	/**
@@ -168,7 +168,7 @@ static <State extends Serializable> FormatterStep createLazy(
 	static <State extends Serializable> FormatterStep create(
 			String name,
 			State state,
-			ThrowingEx.Function<State, FormatterFunc> stateToFormatter) {
+			SerializedFunction<State, FormatterFunc> stateToFormatter) {
 		Objects.requireNonNull(state, "state");
 		return createLazy(name, () -> state, stateToFormatter);
 	}
@@ -185,7 +185,7 @@ static <State extends Serializable> FormatterStep create(
 	static FormatterStep createNeverUpToDateLazy(
 			String name,
 			ThrowingEx.Supplier<FormatterFunc> functionSupplier) {
-		return new FormatterStepImpl.NeverUpToDate(name, functionSupplier);
+		return new NeverUpToDateStep(name, functionSupplier);
 	}
 
 	/**

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/PaddedCellTaskTest.java

@@ -34,6 +34,7 @@
 import com.diffplug.spotless.FormatterFunc;
 import com.diffplug.spotless.FormatterStep;
 import com.diffplug.spotless.LineEnding;
+import com.diffplug.spotless.NeverUpToDateStep;
 import com.diffplug.spotless.ResourceHarness;
 import com.diffplug.spotless.TestProvisioner;
 
@@ -56,7 +57,7 @@ public BuildServiceParameters.None getParameters() {
 		Bundle(String name, FormatterFunc function) throws IOException {
 			this.name = name;
 			file = setFile("src/test." + name).toContent("CCC");
-			FormatterStep step = FormatterStep.createNeverUpToDate(name, function);
+			FormatterStep step = NeverUpToDateStep.create(name, function);
 			source = createFormatTask(name, step);
 			check = createCheckTask(name, source);
 			apply = createApplyTask(name, source);

plugin-maven/src/test/java/com/diffplug/spotless/maven/incremental/PluginFingerprintTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2021-2023 DiffPlug
+ * Copyright 2021-2024 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -39,6 +39,7 @@
 import com.diffplug.spotless.Formatter;
 import com.diffplug.spotless.FormatterStep;
 import com.diffplug.spotless.LineEnding;
+import com.diffplug.spotless.NeverUpToDateStep;
 import com.diffplug.spotless.maven.MavenIntegrationHarness;
 
 class PluginFingerprintTest extends MavenIntegrationHarness {
@@ -162,7 +163,7 @@ private static Model readPom(String xml) throws Exception {
 	}
 
 	private static FormatterStep formatterStep(String name) {
-		return FormatterStep.createNeverUpToDate(name, input -> input);
+		return NeverUpToDateStep.create(name, input -> input);
 	}
 
 	private static Formatter formatter(FormatterStep... steps) {

testlib/src/main/java/com/diffplug/spotless/NeverUpToDateStep.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2024 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;
+
+import java.io.File;
+import java.util.Objects;
+
+/**
+ * Formatter which is equal to itself, but not to any other Formatter.
+ */
+public class NeverUpToDateStep implements FormatterStep {
+	/**
+	 * @param name
+	 *             The name of the formatter step
+	 * @param functionSupplier
+	 *             A supplier which will lazily generate the function
+	 *             used by the formatter step
+	 * @return A FormatterStep which will never report that it is up-to-date, because
+	 *         it is not equal to the serialized representation of itself.
+	 */
+	public static FormatterStep createLazy(
+			String name,
+			ThrowingEx.Supplier<FormatterFunc> functionSupplier) {
+		return new NeverUpToDateStep(name, functionSupplier);
+	}
+
+	/**
+	 * @param name
+	 *             The name of the formatter step
+	 * @param function
+	 *             The function used by the formatter step
+	 * @return A FormatterStep which will never report that it is up-to-date, because
+	 *         it is not equal to the serialized representation of itself.
+	 */
+	public static FormatterStep create(
+			String name,
+			FormatterFunc function) {
+		Objects.requireNonNull(function, "function");
+		return createLazy(name, () -> function);
+	}
+
+	private static final long serialVersionUID = 1L;
+
+	private final String name;
+	private final ThrowingEx.Supplier<FormatterFunc> formatterSupplier;
+	private transient FormatterFunc formatter; // initialized lazily
+
+	NeverUpToDateStep(String name, ThrowingEx.Supplier<FormatterFunc> formatterSupplier) {
+		this.name = name;
+		this.formatterSupplier = Objects.requireNonNull(formatterSupplier, "formatterSupplier");
+	}
+
+	@Override
+	public String getName() {
+		return name;
+	}
+
+	@Override
+	public String format(String rawUnix, File file) throws Exception {
+		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");
+			}
+		}
+		return formatter.apply(rawUnix, file);
+	}
+
+	@Override
+	public void close() throws Exception {
+		if (formatter instanceof FormatterFunc.Closeable) {
+			((FormatterFunc.Closeable) formatter).close();
+			formatter = null;
+		}
+	}
+}

testlib/src/test/java/com/diffplug/spotless/PaddedCellTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2021 DiffPlug
+ * Copyright 2016-2024 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -47,7 +47,7 @@ private void wellBehaved(FormatterFunc step, String input, PaddedCell.Type expec
 
 	private void testCase(FormatterFunc step, String input, PaddedCell.Type expectedOutputType, String expectedSteps, String canonical, boolean misbehaved) throws IOException {
 		List<FormatterStep> formatterSteps = new ArrayList<>();
-		formatterSteps.add(FormatterStep.createNeverUpToDate("step", step));
+		formatterSteps.add(NeverUpToDateStep.create("step", step));
 		try (Formatter formatter = Formatter.builder()
 				.lineEndingsPolicy(LineEnding.UNIX.createPolicy())
 				.encoding(StandardCharsets.UTF_8)