feat: Inlay hints with text edits can be applied when clicking on them

org.eclipse.lsp4e.test/src/org/eclipse/lsp4e/test/operations/inlayhint/LSPLineContentCodeMiningTest.java

@@ -33,6 +33,9 @@
 import org.eclipse.lsp4j.InlayHint;
 import org.eclipse.lsp4j.InlayHintLabelPart;
 import org.eclipse.lsp4j.Position;
+import org.eclipse.lsp4j.Range;
+import org.eclipse.lsp4j.TextEdit;
+import org.eclipse.lsp4j.jsonrpc.messages.Either;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.MouseEvent;
 import org.eclipse.swt.widgets.Display;
@@ -75,6 +78,25 @@ public void singleLabelPartCommand() throws Exception {
 		assertEquals(MockLanguageServer.SUPPORTED_COMMAND_ID, executedCommand.getCommand());
 		assertEquals(command.getArguments(), executedCommand.getArguments());
 	}
+
+	@Test
+	void inlayHintWithTextEdit() throws Exception {
+		IFile file = TestUtils.createUniqueTestFile(project, "lspt", "x = [1, 2]");
+		ITextViewer textViewer = TestUtils.openTextViewer(file);
+		IDocument document = textViewer.getDocument();
+
+		final var provider = new InlayHintProvider();
+
+		InlayHint inlayHint = new InlayHint(new Position(0,0), Either.forLeft(": list[int]"));
+		inlayHint.setTextEdits(List.of(new TextEdit(new Range(new Position(0, 1),new Position(0,1)), ": list[int]")));
+
+		LanguageServerWrapper wrapper = LanguageServiceAccessor.getLSWrapper(project, LanguageServersRegistry.getInstance().getDefinition(MOCK_SERVER_ID));
+		final var sut = new LSPLineContentCodeMining(inlayHint, document, wrapper, provider);
+		MouseEvent mouseEvent = createMouseEvent();
+		sut.getAction().accept(mouseEvent);
+
+		assertEquals(document.get(), "x: list[int] = [1, 2]");
+	}
 
 	private static InlayHintLabelPart createInlayLabelPart(String text, String commandID) {
 		final var labelPart = new InlayHintLabelPart(text);

org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/inlayhint/LSPLineContentCodeMining.java

@@ -111,7 +111,7 @@ private static boolean canResolveInlayHint(@Nullable ServerCapabilities capabili
 		Either<Boolean, InlayHintRegistrationOptions> inlayProvider = capabilities.getInlayHintProvider();
 		if (inlayProvider != null && inlayProvider.isRight()) {
 			InlayHintRegistrationOptions options = inlayProvider.getRight();
-			return options.getResolveProvider() != null && options.getResolveProvider().booleanValue();
+			return Boolean.TRUE.equals(options.getResolveProvider());
 		}
 		return false;
 	}
@@ -134,7 +134,28 @@ private static org.eclipse.jface.text.Position toPosition(Position position, IDo
 
 	@Override
 	public final @Nullable Consumer<MouseEvent> getAction() {
-		return inlayHint.getLabel().map(l -> null, this::labelPartAction);
+		// Check if there is a specific command to execute for the clicked on label part
+		var consumer = inlayHint.getLabel().map(l -> null, this::labelPartAction);
+		if (consumer != null) {
+			return consumer;
+		}
+
+		// Check if there are text edits to apply when clicking on the inlay hint
+		if (inlayHint.getTextEdits() != null && !inlayHint.getTextEdits().isEmpty()) {
+			return evt -> {
+				try {
+					LSPEclipseUtils.applyEdits(document, inlayHint.getTextEdits());
+					// The text of the inlay hint is integrated into the document.
+					// To avoid a brief moment where both the inserted text and the inlay hint are
+					// rendered, we set an empty label for the hint.
+					setLabel(""); //$NON-NLS-1$
+				} catch (BadLocationException e) {
+					// Location to modify document was no longer valid -> Ignore
+				}
+			};
+		}
+
+		return null;
 	}
 
 	private @Nullable Consumer<MouseEvent> labelPartAction(List<InlayHintLabelPart> labelParts) {