Rename FileSignature.RoundTrippable to FileSignature.Promised to match JarState's naming convention.

Author: nedtwigg

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

@@ -97,13 +97,13 @@ private FileSignature(final List<File> files) throws IOException {
 	}
 
 	/** A view of `FileSignature` which can be safely roundtripped. */
-	public static class RoundTrippable implements Serializable {
+	public static class Promised implements Serializable {
 		private static final long serialVersionUID = 1L;
 		private final List<File> files;
 		@SuppressFBWarnings("SE_TRANSIENT_FIELD_NOT_RESTORED")
 		private transient @Nullable FileSignature cached;
 
-		private RoundTrippable(List<File> files, FileSignature cached) {
+		private Promised(List<File> files, FileSignature cached) {
 			this.files = files;
 			this.cached = cached;
 		}
@@ -117,19 +117,23 @@ public FileSignature stripAbsolutePaths() throws IOException {
 		}
 	}
 
-	public RoundTrippable roundTrippable() {
-		return new RoundTrippable(files, this);
+	public static Promised promise(Iterable<File> files) {
+		return new Promised(MoreIterables.toNullHostileList(files), null);
 	}
 
-	public static @Nullable RoundTrippable roundTrippableNullable(@Nullable FileSignature signature) {
+	public Promised roundTrippable() {
+		return new Promised(files, this);
+	}
+
+	public static @Nullable Promised roundTrippableNullable(@Nullable FileSignature signature) {
 		if (signature != null) {
 			return signature.roundTrippable();
 		} else {
 			return null;
 		}
 	}
 
-	public static @Nullable FileSignature stripAbsolutePathsNullable(@Nullable RoundTrippable roundTrippable) throws IOException {
+	public static @Nullable FileSignature stripAbsolutePathsNullable(@Nullable Promised roundTrippable) throws IOException {
 		if (roundTrippable != null) {
 			return roundTrippable.stripAbsolutePaths();
 		} else {

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

@@ -41,7 +41,7 @@ public final class JarState implements Serializable {
 	public static class Promised implements Serializable {
 		private static final long serialVersionUID = 1L;
 		private final transient ThrowingEx.Supplier<JarState> supplier;
-		private FileSignature.RoundTrippable cached;
+		private FileSignature.Promised cached;
 
 		public Promised(ThrowingEx.Supplier<JarState> supplier) {
 			this.supplier = supplier;

lib/src/main/java/com/diffplug/spotless/kotlin/DiktatStep.java

@@ -29,7 +29,7 @@ public class DiktatStep extends FormatterStepEqualityOnStateSerialization<Diktat
 	private static final long serialVersionUID = 1L;
 	private final JarState.Promised jarState;
 	private final boolean isScript;
-	private final @Nullable FileSignature.RoundTrippable config;
+	private final @Nullable FileSignature.Promised config;
 
 	private DiktatStep(JarState.Promised jarState, boolean isScript, @Nullable FileSignature config) {
 		this.jarState = jarState;