refact: enable NonNullByDefault for lsp4e.refactoring package

org.eclipse.lsp4e/src/org/eclipse/lsp4e/refactoring/CreateFileChange.java

@@ -37,6 +37,7 @@
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.SubMonitor;
 import org.eclipse.core.runtime.content.IContentType;
+import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.lsp4e.LSPEclipseUtils;
 import org.eclipse.lsp4e.LanguageServerPlugin;
 import org.eclipse.lsp4e.ui.Messages;
@@ -51,15 +52,15 @@ public class CreateFileChange extends ResourceChange {
 
 	private final URI uri;
 	private final String fSource;
-	private String fEncoding;
+	private @Nullable String fEncoding;
 	private boolean fExplicitEncoding;
 	private final long fStampToRestore;
 
-	public CreateFileChange(URI uri, String source, String encoding) {
+	public CreateFileChange(URI uri, String source, @Nullable String encoding) {
 		this(uri, source, encoding, IResource.NULL_STAMP);
 	}
 
-	public CreateFileChange(URI uri, String source, String encoding, long stampToRestore) {
+	public CreateFileChange(URI uri, String source, @Nullable String encoding, long stampToRestore) {
 		Assert.isNotNull(uri, "uri"); //$NON-NLS-1$
 		Assert.isNotNull(source, "source"); //$NON-NLS-1$
 		this.uri = uri;
@@ -81,7 +82,7 @@ public String getName() {
 	}
 
 	@Override
-	protected IFile getModifiedResource() {
+	protected @Nullable IFile getModifiedResource() {
 		return LSPEclipseUtils.getFileHandle(this.uri);
 	}
 
@@ -98,10 +99,10 @@ public RefactoringStatus isValid(IProgressMonitor pm) throws CoreException {
 	}
 
 	@Override
-	public Change perform(IProgressMonitor pm) throws CoreException {
+	public @Nullable Change perform(IProgressMonitor pm) throws CoreException {
 		pm.beginTask(NLS.bind(Messages.edit_CreateFile, uri), 3);
 
-		initializeEncoding();
+		final var fEncoding = initializeEncoding();
 
 		try (InputStream is= new ByteArrayInputStream(fSource.getBytes(fEncoding))) {
 
@@ -158,7 +159,7 @@ public Change perform(IProgressMonitor pm) throws CoreException {
 		return null;
 	}
 
-	private void initializeEncoding() {
+	private String initializeEncoding() {
 		if (fEncoding == null) {
 			fExplicitEncoding= false;
 			IFile ifile = getModifiedResource();
@@ -188,5 +189,6 @@ private void initializeEncoding() {
 			}
 		}
 		Assert.isNotNull(fEncoding);
+		return fEncoding;
 	}
 }

org.eclipse.lsp4e/src/org/eclipse/lsp4e/refactoring/DeleteExternalFile.java

@@ -19,16 +19,16 @@
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
-import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.lsp4e.LanguageServerPlugin;
 import org.eclipse.ltk.core.refactoring.Change;
 import org.eclipse.ltk.core.refactoring.RefactoringStatus;
 
 public class DeleteExternalFile extends Change {
 
-	private final @NonNull File file;
+	private final File file;
 
-	public DeleteExternalFile(@NonNull File file) {
+	public DeleteExternalFile(File file) {
 		this.file = file;
 	}
 
@@ -48,7 +48,7 @@ public RefactoringStatus isValid(IProgressMonitor pm) throws CoreException {
 	}
 
 	@Override
-	public Change perform(IProgressMonitor pm) throws CoreException {
+	public @Nullable Change perform(IProgressMonitor pm) throws CoreException {
 		try {
 			Files.delete(this.file.toPath());
 		} catch (IOException e) {

org.eclipse.lsp4e/src/org/eclipse/lsp4e/refactoring/LSPTextChange.java

@@ -11,6 +11,8 @@
  *******************************************************************************/
 package org.eclipse.lsp4e.refactoring;
 
+import static org.eclipse.lsp4e.internal.NullSafetyHelper.*;
+
 import java.net.URI;
 
 import org.eclipse.core.filebuffers.FileBuffers;
@@ -26,7 +28,7 @@
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.SubMonitor;
-import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.lsp4e.LSPEclipseUtils;
@@ -47,22 +49,22 @@
 @SuppressWarnings("restriction")
 public class LSPTextChange extends TextChange {
 
-	private final @NonNull URI fileUri;
+	private final URI fileUri;
 
-	private Either<IFile, IFileStore> file;
+	private Either<IFile, IFileStore> file = lateNonNull();
 	private int fAcquireCount;
-	private ITextFileBuffer fBuffer;
-	private @NonNull String newText;
-	private Range range;
+	private @Nullable ITextFileBuffer fBuffer;
+	private String newText;
+	private @Nullable Range range;
 
-	public LSPTextChange(@NonNull String name, @NonNull URI fileUri, @NonNull TextEdit textEdit) {
+	public LSPTextChange(String name, URI fileUri, TextEdit textEdit) {
 		super(name);
 		this.fileUri = fileUri;
 		this.newText = textEdit.getNewText();
 		this.range = textEdit.getRange();
 	}
 
-	public LSPTextChange(@NonNull String name, @NonNull URI fileUri, @NonNull String newText) {
+	public LSPTextChange(String name, URI fileUri, String newText) {
 		super(name);
 		this.fileUri = fileUri;
 		this.newText = newText;
@@ -73,7 +75,7 @@ public LSPTextChange(@NonNull String name, @NonNull URI fileUri, @NonNull String
 	protected IDocument acquireDocument(IProgressMonitor pm) throws CoreException {
 		fAcquireCount++;
 		if (fAcquireCount > 1) {
-			return fBuffer.getDocument();
+			return castNonNull(this.fBuffer).getDocument();
 		}
 
 		IFile iFile = LSPEclipseUtils.getFileHandle(this.fileUri);
@@ -106,9 +108,10 @@ protected IDocument acquireDocument(IProgressMonitor pm) throws CoreException {
 		// because that's used by the preview logic to compute the changed document. We do it here rather than in the constructor
 		// since we need the document to translate line offsets into character offset. Strictly this would not work then
 		// if the platform called getEdit() prior to this method being traversed, but it seems to be OK in practice.
-		final IDocument document  = fBuffer.getDocument();
+		final IDocument document = castNonNull(this.fBuffer).getDocument();
 		int offset = 0;
 		int length = document.getLength();
+		final var range = this.range;
 		if (range != null && getEdit() == null) {
 			try {
 				offset = LSPEclipseUtils.toOffset(range.getStart(), document);
@@ -124,15 +127,15 @@ protected IDocument acquireDocument(IProgressMonitor pm) throws CoreException {
 
 	@Override
 	protected void commit(IDocument document, IProgressMonitor pm) throws CoreException {
-		this.fBuffer.commit(pm, true);
+		castNonNull(this.fBuffer).commit(pm, true);
 	}
 
 	@Override
 	protected void releaseDocument(IDocument document, IProgressMonitor pm) throws CoreException {
 		Assert.isTrue(fAcquireCount > 0);
 		if (fAcquireCount == 1) {
 			ITextFileBufferManager manager = FileBuffers.getTextFileBufferManager();
-			this.fBuffer.commit(pm, true);
+			castNonNull(this.fBuffer).commit(pm, true);
 			if (this.file.isLeft()) {
 				manager.disconnect(this.file.getLeft().getFullPath(), LocationKind.IFILE, pm);
 			} else {
@@ -143,7 +146,7 @@ protected void releaseDocument(IDocument document, IProgressMonitor pm) throws C
 	}
 
 	@Override
-	protected Change createUndoChange(UndoEdit edit) {
+	protected @Nullable Change createUndoChange(UndoEdit edit) {
 		throw new UnsupportedOperationException("Should not be called!"); //$NON-NLS-1$
 	}
 
@@ -158,7 +161,7 @@ public RefactoringStatus isValid(IProgressMonitor pm) throws CoreException {
 	}
 
 	@Override
-	public Object getModifiedElement() {
+	public @Nullable Object getModifiedElement() {
 		IFile file = LSPEclipseUtils.getFileHandle(this.fileUri);
 		if (file != null) {
 			return file;
@@ -170,7 +173,7 @@ public Object getModifiedElement() {
 	}
 
 	@Override
-	public Change perform(IProgressMonitor pm) throws CoreException {
+	public @Nullable Change perform(IProgressMonitor pm) throws CoreException {
 		pm.beginTask("", 3); //$NON-NLS-1$
 		IDocument document = null;
 
@@ -179,6 +182,7 @@ public Change perform(IProgressMonitor pm) throws CoreException {
 
 			int offset = 0;
 			int length = document.getLength();
+			final var range = this.range;
 			if (range != null) {
 				offset = LSPEclipseUtils.toOffset(range.getStart(), document);
 				length = LSPEclipseUtils.toOffset(range.getEnd(), document) - offset;

org.eclipse.lsp4e/src/org/eclipse/lsp4e/refactoring/package-info.java

@@ -0,0 +1,6 @@
+@NonNullByDefault({ ARRAY_CONTENTS, PARAMETER, RETURN_TYPE, FIELD, TYPE_BOUND, TYPE_ARGUMENT })
+package org.eclipse.lsp4e.refactoring;
+
+import static org.eclipse.jdt.annotation.DefaultLocation.*;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;