From 3e125c78ce7b02779002658fcd3ed64386a40e25 Mon Sep 17 00:00:00 2001
From: Maria Solano <mariasolano@microsoft.com>
Date: Thu, 26 Oct 2023 12:03:36 -0700
Subject: [PATCH] Snippet text edits

---
 client-node-tests/src/helpers.test.ts  | 23 +++++----
 client/src/common/client.ts            |  1 +
 client/src/common/protocolConverter.ts |  2 +
 protocol/src/common/protocol.ts        | 10 +++-
 types/src/main.ts                      | 66 ++++++++++++++++++++++----
 5 files changed, 84 insertions(+), 18 deletions(-)

diff --git a/client-node-tests/src/helpers.test.ts b/client-node-tests/src/helpers.test.ts
index 90dffd73e..bf38631a7 100644
--- a/client-node-tests/src/helpers.test.ts
+++ b/client-node-tests/src/helpers.test.ts
@@ -8,7 +8,8 @@ import { strictEqual, ok } from 'assert';
 import {
 	Position, Range, TextDocumentIdentifier, TextDocumentItem, VersionedTextDocumentIdentifier, Command, CodeLens, CodeActionContext,
 	Diagnostic, DiagnosticSeverity, WorkspaceChange, TextDocumentEdit, CreateFile, RenameFile, DeleteFile, ChangeAnnotation,
-	AnnotatedTextEdit
+	AnnotatedTextEdit,
+	TextEdit
 } from 'vscode-languageclient';
 
 suite('Protocol Helper Tests', () => {
@@ -124,17 +125,21 @@ suite('Protocol Helper Tests', () => {
 		strictEqual(workspaceEdit.documentChanges!.length, 2);
 		let edits = (workspaceEdit.documentChanges![0] as TextDocumentEdit).edits;
 		strictEqual(edits.length, 3);
-		rangeEqual(edits[0].range, Range.create(0,1,0,1));
-		strictEqual(edits[0].newText, 'insert');
-		rangeEqual(edits[1].range, Range.create(0,1,2,3));
-		strictEqual(edits[1].newText, 'replace');
-		rangeEqual(edits[2].range, Range.create(0,1,2,3));
-		strictEqual(edits[2].newText, '');
+		let edit = edits[0] as TextEdit;
+		rangeEqual(edit.range, Range.create(0,1,0,1));
+		strictEqual(edit.newText, 'insert');
+		edit = edits[1] as TextEdit;
+		rangeEqual(edit.range, Range.create(0,1,2,3));
+		strictEqual(edit.newText, 'replace');
+		edit = edits[2] as TextEdit;
+		rangeEqual(edit.range, Range.create(0,1,2,3));
+		strictEqual(edit.newText, '');
 
 		edits = (workspaceEdit.documentChanges![1] as TextDocumentEdit).edits;
 		strictEqual(edits.length, 1);
-		rangeEqual(edits[0].range, Range.create(2,3,2,3));
-		strictEqual(edits[0].newText, 'insert');
+		edit = edits[0] as TextEdit;
+		rangeEqual(edit.range, Range.create(2,3,2,3));
+		strictEqual(edit.newText, 'insert');
 
 		workspaceChange.createFile('file:///create.txt');
 		workspaceChange.renameFile('file:///old.txt', 'file:///new.txt');
diff --git a/client/src/common/client.ts b/client/src/common/client.ts
index bf121286d..2e04e59a7 100644
--- a/client/src/common/client.ts
+++ b/client/src/common/client.ts
@@ -1836,6 +1836,7 @@ export abstract class BaseLanguageClient implements FeatureClient<Middleware, La
 		workspaceEdit.changeAnnotationSupport = {
 			groupsOnLabel: true
 		};
+		workspaceEdit.snippetEditSupport = true;
 
 		const diagnostics = ensure(ensure(result, 'textDocument')!, 'publishDiagnostics')!;
 		diagnostics.relatedInformation = true;
diff --git a/client/src/common/protocolConverter.ts b/client/src/common/protocolConverter.ts
index 30c132ef7..3a9c0fc92 100644
--- a/client/src/common/protocolConverter.ts
+++ b/client/src/common/protocolConverter.ts
@@ -1088,6 +1088,8 @@ export function createConverter(uriConverter: URIConverter | undefined, trustMar
 					for (const edit of change.edits) {
 						if (ls.AnnotatedTextEdit.is(edit)) {
 							result.replace(uri, asRange(edit.range), edit.newText, asMetadata(edit.annotationId));
+						} else if (ls.SnippetTextEdit.is(edit)) {
+							result.replace(uri, asRange(edit.range), edit.snippet.value, asMetadata(edit.annotationId));
 						} else {
 							result.replace(uri, asRange(edit.range), edit.newText);
 						}
diff --git a/protocol/src/common/protocol.ts b/protocol/src/common/protocol.ts
index 0df3e84bb..7e23dd367 100644
--- a/protocol/src/common/protocol.ts
+++ b/protocol/src/common/protocol.ts
@@ -4094,6 +4094,14 @@ export interface WorkspaceEditClientCapabilities {
 	 * @since 3.16.0
 	 */
 	changeAnnotationSupport?: ChangeAnnotationsSupportOptions;
+
+	/**
+	 * Whether the client supports snippets as text edits.
+	 *
+	 * @since 3.18.0
+	 * @proposed
+	 */
+	snippetEditSupport?: boolean;
 }
 
 /**
@@ -4207,7 +4215,7 @@ export {
 	DidChangeNotebookDocumentNotification, DidSaveNotebookDocumentParams, DidSaveNotebookDocumentNotification, DidCloseNotebookDocumentParams,
 	DidCloseNotebookDocumentNotification,
 	// Inline Completions
-	InlineCompletionClientCapabilities, InlineCompletionOptions, InlineCompletionParams, InlineCompletionRegistrationOptions, InlineCompletionRequest
+	InlineCompletionClientCapabilities, InlineCompletionOptions, InlineCompletionParams, InlineCompletionRegistrationOptions, InlineCompletionRequest,
 };
 
 // To be backwards compatible
diff --git a/types/src/main.ts b/types/src/main.ts
index b07fce714..781035901 100644
--- a/types/src/main.ts
+++ b/types/src/main.ts
@@ -1026,8 +1026,11 @@ export interface TextDocumentEdit {
 	 *
 	 * @since 3.16.0 - support for AnnotatedTextEdit. This is guarded using a
 	 * client capability.
+	 *
+	 * @since 3.18.0 - support for SnippetTextEdit. This is guarded using a
+	 * client capability.
 	 */
-	edits: (TextEdit | AnnotatedTextEdit)[];
+	edits: (TextEdit | AnnotatedTextEdit | SnippetTextEdit)[];
 }
 
 /**
@@ -1038,7 +1041,7 @@ export namespace TextDocumentEdit {
 	/**
 	 * Creates a new `TextDocumentEdit`
 	 */
-	export function create(textDocument: OptionalVersionedTextDocumentIdentifier, edits: (TextEdit | AnnotatedTextEdit)[]): TextDocumentEdit {
+	export function create(textDocument: OptionalVersionedTextDocumentIdentifier, edits: (TextEdit | AnnotatedTextEdit | SnippetTextEdit)[]): TextDocumentEdit {
 		return { textDocument, edits };
 	}
 
@@ -1330,8 +1333,11 @@ export interface TextEditChange {
 	 *
 	 * @since 3.16.0 - support for annotated text edits. This is usually
 	 * guarded using a client capability.
+	 *
+	 * @since 3.18.0 - support for snippet text edits. This is usually
+	 * guarded using a client capability.
 	 */
-	all(): (TextEdit | AnnotatedTextEdit)[];
+	all(): (TextEdit | AnnotatedTextEdit | SnippetTextEdit)[];
 
 	/**
 	 * Clears the edits for this change.
@@ -1345,8 +1351,11 @@ export interface TextEditChange {
 	 *
 	 * @since 3.16.0 - support for annotated text edits. This is usually
 	 * guarded using a client capability.
+	 *
+	 * @since 3.18.0 - support for snippet text edits. This is usually
+	 * guarded using a client capability.
 	 */
-	add(edit: TextEdit | AnnotatedTextEdit): void;
+	add(edit: TextEdit | AnnotatedTextEdit | SnippetTextEdit): void;
 
 	/**
 	 * Insert the given text at the given position.
@@ -1380,10 +1389,10 @@ export interface TextEditChange {
 
 class TextEditChangeImpl implements TextEditChange {
 
-	private edits: (TextEdit | AnnotatedTextEdit)[];
+	private edits: (TextEdit | AnnotatedTextEdit | SnippetTextEdit)[];
 	private changeAnnotations: ChangeAnnotations | undefined;
 
-	public constructor(edits: (TextEdit | AnnotatedTextEdit)[], changeAnnotations?: ChangeAnnotations) {
+	public constructor(edits: (TextEdit | AnnotatedTextEdit | SnippetTextEdit)[], changeAnnotations?: ChangeAnnotations) {
 		this.edits = edits;
 		this.changeAnnotations = changeAnnotations;
 	}
@@ -1451,11 +1460,11 @@ class TextEditChangeImpl implements TextEditChange {
 		}
 	}
 
-	public add(edit: TextEdit | AnnotatedTextEdit): void {
+	public add(edit: TextEdit | AnnotatedTextEdit | SnippetTextEdit): void {
 		this.edits.push(edit);
 	}
 
-	public all(): (TextEdit | AnnotatedTextEdit)[] {
+	public all(): (TextEdit | AnnotatedTextEdit | SnippetTextEdit)[] {
 		return this.edits;
 	}
 
@@ -1470,6 +1479,39 @@ class TextEditChangeImpl implements TextEditChange {
 	}
 }
 
+/**
+ * An interactive text edit.
+ *
+ * @since 3.18.0
+ * @proposed
+ */
+export interface SnippetTextEdit {
+	/**
+	 * The range of the text document to be manipulated.
+	 */
+	range: Range;
+
+	/**
+	 * The snippet to be inserted.
+	 */
+	snippet: StringValue;
+
+	/**
+	 * The actual identifier of the snippet edit.
+	 */
+	annotationId?: ChangeAnnotationIdentifier;
+}
+
+export namespace SnippetTextEdit {
+	export function is(value: any): value is SnippetTextEdit {
+		const candidate = value as SnippetTextEdit;
+		return Is.objectLiteral(candidate)
+			&& Range.is(candidate.range)
+			&& StringValue.isSnippet(candidate.snippet)
+			&& (ChangeAnnotation.is(candidate.annotationId) || ChangeAnnotationIdentifier.is(candidate.annotationId));
+	}
+}
+
 /**
  * A helper class
  */
@@ -4291,6 +4333,7 @@ export interface StringValue {
 	 * The kind of string value.
 	 */
 	kind: 'snippet';
+
 	/**
 	 * The snippet string.
 	 */
@@ -4301,6 +4344,13 @@ export namespace StringValue {
 	export function createSnippet(value: string): StringValue {
 		return { kind: 'snippet', value };
 	}
+
+	export function isSnippet(value: any): value is StringValue {
+		const candidate = value as StringValue;
+		return Is.objectLiteral(candidate)
+			&& candidate.kind === 'snippet'
+			&& Is.string(candidate.value);
+	}
 }
 
 /**