Merge pull request #101 from diffplug/issue-86

Added significantly more early null checks throughout Spotless.

Author: nedtwigg

lib-extra/src/main/java/com/diffplug/spotless/extra/GitAttributesLineEndings.java

@@ -15,6 +15,8 @@
  */
 package com.diffplug.spotless.extra;
 
+import static com.diffplug.spotless.extra.LibExtraPreconditions.requireElementsNonNull;
+
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -81,8 +83,8 @@ static class Policy extends LazyForwardingEquality<FileState> implements LineEnd
 		final transient Supplier<Iterable<File>> toFormat;
 
 		Policy(File projectDir, Supplier<Iterable<File>> toFormat) {
-			this.projectDir = Objects.requireNonNull(projectDir);
-			this.toFormat = Objects.requireNonNull(toFormat);
+			this.projectDir = Objects.requireNonNull(projectDir, "projectDir");
+			this.toFormat = Objects.requireNonNull(toFormat, "toFormat");
 		}
 
 		@Override
@@ -126,8 +128,7 @@ static class FileState implements Serializable {
 
 		@SuppressFBWarnings("SIC_INNER_SHOULD_BE_STATIC_ANON")
 		FileState(File projectDir, Iterable<File> toFormat) throws IOException {
-			Objects.requireNonNull(projectDir);
-			Objects.requireNonNull(toFormat);
+			requireElementsNonNull(toFormat);
 			/////////////////////////////////
 			// USER AND SYSTEM-WIDE VALUES //
 			/////////////////////////////////

lib-extra/src/main/java/com/diffplug/spotless/extra/LibExtraPreconditions.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2016 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.extra;
+
+import java.util.Objects;
+
+final class LibExtraPreconditions {
+	// prevent direct instantiation
+	private LibExtraPreconditions() {}
+
+	static <T, I extends Iterable<T>> I requireElementsNonNull(I elements) {
+		Objects.requireNonNull(elements);
+		for (Object element : elements) {
+			Objects.requireNonNull(element);
+		}
+		return elements;
+	}
+}

lib-extra/src/main/java/com/diffplug/spotless/extra/groovy/GrEclipseFormatterStep.java

@@ -31,10 +31,6 @@
 
 /** Formatter step which calls out to the Groovy-Eclipse formatter. */
 public class GrEclipseFormatterStep {
-	public static final String defaultVersion() {
-		return DEFAULT_VERSION;
-	}
-
 	private static final String NAME = "groovy-eclipse formatter";
 	private static final String FORMATTER_CLASS = "com.diffplug.gradle.spotless.groovy.eclipse.GrEclipseFormatterStepImpl";
 	private static final String DEFAULT_VERSION = "2.3.0";
@@ -54,6 +50,10 @@ public static FormatterStep create(String version, Iterable<File> settingsFiles,
 				State::createFormat);
 	}
 
+	public static String defaultVersion() {
+		return DEFAULT_VERSION;
+	}
+
 	private static class State implements Serializable {
 		private static final long serialVersionUID = 1L;
 

lib-extra/src/main/java/com/diffplug/spotless/extra/java/EclipseFormatterStep.java

@@ -18,7 +18,7 @@
 import java.io.File;
 import java.io.Serializable;
 import java.lang.reflect.Method;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.Objects;
 import java.util.Properties;
 
@@ -45,7 +45,7 @@ private EclipseFormatterStep() {}
 	 * to many files. Use {@link #create(Iterable, Provisioner)} instead.*/
 	@Deprecated
 	public static FormatterStep create(File settingsFile, Provisioner provisioner) {
-		return create(Arrays.asList(settingsFile), provisioner);
+		return create(Collections.singletonList(settingsFile), provisioner);
 	}
 
 	/** Creates a formatter step for the given version and settings file. */
@@ -58,11 +58,14 @@ public static FormatterStep create(Iterable<File> settingsFiles, Provisioner pro
 	 * to many files. Use {@link #create(String, Iterable, Provisioner)} instead.*/
 	@Deprecated
 	public static FormatterStep create(String version, File settingsFile, Provisioner provisioner) {
-		return create(version, Arrays.asList(settingsFile), provisioner);
+		return create(version, Collections.singletonList(settingsFile), provisioner);
 	}
 
 	/** Creates a formatter step for the given version and settings files. */
 	public static FormatterStep create(String version, Iterable<File> settingsFiles, Provisioner provisioner) {
+		Objects.requireNonNull(version, "version");
+		Objects.requireNonNull(settingsFiles, "settingsFiles");
+		Objects.requireNonNull(provisioner, "provisioner");
 		return FormatterStep.createLazy(NAME,
 				() -> new State(JarState.from(MAVEN_COORDINATE + version, provisioner), settingsFiles),
 				State::createFormat);
@@ -81,7 +84,7 @@ private static class State implements Serializable {
 		final FileSignature settings;
 
 		State(JarState jar, final Iterable<File> settingsFiles) throws Exception {
-			this.jarState = Objects.requireNonNull(jar);
+			this.jarState = jar;
 			this.settings = FileSignature.signAsList(settingsFiles);
 		}
 

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

@@ -15,14 +15,15 @@
  */
 package com.diffplug.spotless;
 
+import static com.diffplug.spotless.MoreIterables.toNullHostileList;
+import static com.diffplug.spotless.MoreIterables.toSortedSet;
+
 import java.io.File;
 import java.io.IOException;
 import java.io.Serializable;
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Iterator;
 import java.util.List;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
@@ -66,7 +67,7 @@ public static FileSignature signAsList(File... files) throws IOException {
 
 	/** Creates file signature whereas order of the files remains unchanged. */
 	public static FileSignature signAsList(Iterable<File> files) throws IOException {
-		return new FileSignature(asNonNullList(files));
+		return new FileSignature(toNullHostileList(files));
 	}
 
 	/** Creates file signature whereas order of the files remains unchanged. */
@@ -109,36 +110,4 @@ public File getOnlyFile() {
 		}
 	}
 
-	/** Sorts "toBeSorted" and removes duplicates. */
-	static <T extends Comparable<T>> List<T> toSortedSet(Iterable<T> raw) {
-		List<T> toBeSorted = asNonNullList(raw);
-		// sort it
-		Collections.sort(toBeSorted);
-		// remove any duplicates (normally there won't be any)
-		if (toBeSorted.size() > 1) {
-			Iterator<T> iter = toBeSorted.iterator();
-			T last = iter.next();
-			while (iter.hasNext()) {
-				T next = iter.next();
-				if (next.compareTo(last) == 0) {
-					iter.remove();
-				} else {
-					last = next;
-				}
-			}
-		}
-		return toBeSorted;
-	}
-
-	/** Returns a shallow copy of input elements omitting null elements */
-	private static <T> List<T> asNonNullList(Iterable<T> input) {
-		List<T> shallowCopy = (input instanceof Collection)
-				? new ArrayList<T>(((Collection<?>) input).size())
-				: new ArrayList<T>();
-		input.forEach(element -> {
-			if (null != element)
-				shallowCopy.add(element);
-		});
-		return shallowCopy;
-	}
 }

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

@@ -36,6 +36,8 @@ public String getName() {
 
 	@Override
 	public @Nullable String format(String raw, File file) throws Exception {
+		Objects.requireNonNull(raw, "raw");
+		Objects.requireNonNull(file, "file");
 		if (filter.accept(file)) {
 			return delegateStep.format(raw, file);
 		} else {

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

@@ -20,7 +20,7 @@
 /** A policy for handling exceptions in the format. */
 public interface FormatExceptionPolicy extends Serializable, NoLambda {
 	/** Called for every error in the formatter. */
-	void handleError(Throwable e, FormatterStep step, String relativePath);
+	public void handleError(Throwable e, FormatterStep step, String relativePath);
 
 	/**
 	 * Returns a byte array representation of everything inside this `FormatExceptionPolicy`.

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

@@ -15,6 +15,7 @@
  */
 package com.diffplug.spotless;
 
+import java.util.Objects;
 import java.util.Set;
 import java.util.TreeSet;
 
@@ -30,16 +31,19 @@ public class FormatExceptionPolicyStrict extends NoLambda.EqualityBasedOnSeriali
 
 	/** Adds a step name to exclude. */
 	public void excludeStep(String stepName) {
-		excludeSteps.add(stepName);
+		excludeSteps.add(Objects.requireNonNull(stepName));
 	}
 
 	/** Adds a realtive pathx to exclude. */
 	public void excludePath(String relativePath) {
-		excludePaths.add(relativePath);
+		excludePaths.add(Objects.requireNonNull(relativePath));
 	}
 
 	@Override
 	public void handleError(Throwable e, FormatterStep step, String relativePath) {
+		Objects.requireNonNull(e, "e");
+		Objects.requireNonNull(step, "step");
+		Objects.requireNonNull(relativePath, "relativePath");
 		if (excludeSteps.contains(step.getName())) {
 			FormatExceptionPolicyLegacy.warning(e, step, relativePath);
 		} else {

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

@@ -15,6 +15,8 @@
  */
 package com.diffplug.spotless;
 
+import static com.diffplug.spotless.LibPreconditions.requireElementsNonNull;
+
 import java.io.File;
 import java.io.IOException;
 import java.io.ObjectInputStream;
@@ -47,7 +49,7 @@ private Formatter(LineEnding.Policy lineEndingsPolicy, Charset encoding, Path ro
 		this.lineEndingsPolicy = Objects.requireNonNull(lineEndingsPolicy, "lineEndingsPolicy");
 		this.encoding = Objects.requireNonNull(encoding, "encoding");
 		this.rootDir = Objects.requireNonNull(rootDirectory, "rootDir");
-		this.steps = new ArrayList<>(Objects.requireNonNull(steps, "steps"));
+		this.steps = requireElementsNonNull(new ArrayList<>(steps));
 		this.exceptionPolicy = Objects.requireNonNull(exceptionPolicy, "exceptionPolicy");
 	}
 
@@ -143,6 +145,8 @@ public Formatter build() {
 
 	/** Returns true iff the given file's formatting is up-to-date. */
 	public boolean isClean(File file) throws IOException {
+		Objects.requireNonNull(file);
+
 		String raw = new String(Files.readAllBytes(file.toPath()), encoding);
 		String unix = LineEnding.toUnix(raw);
 
@@ -178,6 +182,8 @@ public void applyTo(File file) throws IOException {
 	 * formatted result with unix newlines if it was not.
 	 */
 	public @Nullable String applyToAndReturnResultIfDirty(File file) throws IOException {
+		Objects.requireNonNull(file);
+
 		byte[] rawBytes = Files.readAllBytes(file.toPath());
 		String raw = new String(rawBytes, encoding);
 		String rawUnix = LineEnding.toUnix(raw);
@@ -199,6 +205,9 @@ public void applyTo(File file) throws IOException {
 
 	/** Applies the appropriate line endings to the given unix content. */
 	public String computeLineEndings(String unix, File file) {
+		Objects.requireNonNull(unix, "unix");
+		Objects.requireNonNull(file, "file");
+
 		String ending = lineEndingsPolicy.getEndingFor(file);
 		if (!ending.equals(LineEnding.UNIX.str())) {
 			return unix.replace(LineEnding.UNIX.str(), ending);
@@ -213,6 +222,9 @@ public String computeLineEndings(String unix, File file) {
 	 * is guaranteed to also have unix line endings.
 	 */
 	public String compute(String unix, File file) {
+		Objects.requireNonNull(unix, "unix");
+		Objects.requireNonNull(file, "file");
+
 		for (FormatterStep step : steps) {
 			try {
 				String formatted = step.format(unix, file);

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

@@ -15,6 +15,8 @@
  */
 package com.diffplug.spotless;
 
+import java.util.Objects;
+
 /** A `Function<String, String>` which can throw an exception. */
 public interface FormatterFunc extends ThrowingEx.Function<String, String> {
 	/** A `Function<String, String>` whose implementation requires a resource which should be released when the function is no longer needed. */
@@ -24,6 +26,8 @@ interface Closeable extends FormatterFunc, AutoCloseable {
 
 		/** Creates a {@link Closeable} from an AutoCloseable and a function. */
 		public static Closeable of(AutoCloseable closeable, FormatterFunc function) {
+			Objects.requireNonNull(closeable, "closeable");
+			Objects.requireNonNull(function, "function");
 			return new Closeable() {
 				@Override
 				public void close() {
@@ -32,7 +36,7 @@ public void close() {
 
 				@Override
 				public String apply(String input) throws Exception {
-					return function.apply(input);
+					return function.apply(Objects.requireNonNull(input));
 				}
 			};
 		}