Adds support for snippets in inline completions (fixes #138260)

src/vs/editor/common/languages.ts

@@ -786,8 +786,11 @@ export interface InlineCompletion {
 	 * The text to insert.
 	 * If the text contains a line break, the range must end at the end of a line.
 	 * If existing text should be replaced, the existing text must be a prefix of the text to insert.
+	 *
+	 * The text can also be a snippet. In that case, a preview with default parameters is shown.
+	 * When accepting the suggestion, the full snippet is inserted.
 	*/
-	readonly text: string;
+	readonly text: string | { snippet: string };
 
 	/**
 	 * The range to replace.

src/vs/editor/contrib/inlineCompletions/browser/ghostText.ts

@@ -56,6 +56,10 @@ export class GhostText {
 
 		return text.substring(this.parts[0].column - 1);
 	}
+
+	isEmpty(): boolean {
+		return this.parts.every(p => p.lines.length === 0);
+	}
 }
 
 class PositionOffsetTransformer {

src/vs/editor/contrib/inlineCompletions/browser/ghostTextController.ts

@@ -156,6 +156,7 @@ export class ActiveGhostTextController extends Disposable {
 	private updateContextKeys(): void {
 		this.contextKeys.inlineCompletionVisible.set(
 			this.model.activeInlineCompletionsModel?.ghostText !== undefined
+			&& !this.model.activeInlineCompletionsModel.ghostText.isEmpty()
 		);
 
 		let startsWithIndentation = false;

src/vs/editor/contrib/inlineCompletions/browser/inlineCompletionToGhostText.ts

@@ -15,7 +15,16 @@ import { GhostText, GhostTextPart } from 'vs/editor/contrib/inlineCompletions/br
  * A normalized inline completion is an inline completion with a defined range.
 */
 export interface NormalizedInlineCompletion extends InlineCompletion {
-	range: Range;
+	readonly range: Range;
+	readonly text: string;
+
+	readonly snippetInfo:
+	| {
+		snippet: string;
+		/* Could be different than the main range */
+		range: Range;
+	}
+	| undefined;
 }
 
 export function normalizedInlineCompletionsEquals(a: NormalizedInlineCompletion | undefined, b: NormalizedInlineCompletion | undefined): boolean {
@@ -76,7 +85,8 @@ export function inlineCompletionToGhostText(
 		inlineCompletion = {
 			range: rangeThatDoesNotReplaceIndentation,
 			text: suggestionWithoutIndentationChange,
-			command: inlineCompletion.command
+			command: inlineCompletion.command,
+			snippetInfo: undefined,
 		};
 	}
 

src/vs/editor/contrib/inlineCompletions/browser/inlineCompletionsModel.ts

@@ -27,6 +27,9 @@ import { fixBracketsInLine } from 'vs/editor/common/model/bracketPairsTextModelP
 import { LanguageFeatureRegistry } from 'vs/editor/common/languageFeatureRegistry';
 import { ILanguageFeaturesService } from 'vs/editor/common/services/languageFeatures';
 import { IFeatureDebounceInformation, ILanguageFeatureDebounceService } from 'vs/editor/common/services/languageFeatureDebounce';
+import { SnippetParser } from 'vs/editor/contrib/snippet/browser/snippetParser';
+import { SnippetController2 } from 'vs/editor/contrib/snippet/browser/snippetController2';
+import { assertNever } from 'vs/base/common/types';
 
 export class InlineCompletionsModel
 	extends Disposable
@@ -416,7 +419,8 @@ export class InlineCompletionsSession extends BaseGhostTextWidgetModel {
 	}
 
 	public commitCurrentCompletion(): void {
-		if (!this.ghostText) {
+		const ghostText = this.ghostText;
+		if (!ghostText || ghostText.isEmpty()) {
 			// No ghost text was shown for this completion.
 			// Thus, we don't want to commit anything.
 			return;
@@ -432,12 +436,23 @@ export class InlineCompletionsSession extends BaseGhostTextWidgetModel {
 		// otherwise command args might get disposed.
 		const cache = this.cache.clearAndLeak();
 
-		this.editor.executeEdits(
-			'inlineSuggestion.accept',
-			[
-				EditOperation.replaceMove(completion.range, completion.text)
-			]
-		);
+		if (completion.snippetInfo) {
+			this.editor.executeEdits(
+				'inlineSuggestion.accept',
+				[
+					EditOperation.replaceMove(completion.range, '')
+				]
+			);
+			this.editor.setPosition(completion.snippetInfo.range.getStartPosition());
+			SnippetController2.get(this.editor)?.insert(completion.snippetInfo.snippet);
+		} else {
+			this.editor.executeEdits(
+				'inlineSuggestion.accept',
+				[
+					EditOperation.replaceMove(completion.range, completion.text)
+				]
+			);
+		}
 		if (completion.command) {
 			this.commandService
 				.executeCommand(completion.command.id, ...(completion.command.arguments || []))
@@ -543,6 +558,8 @@ class CachedInlineCompletion {
 			sourceProvider: this.inlineCompletion.sourceProvider,
 			sourceInlineCompletions: this.inlineCompletion.sourceInlineCompletions,
 			sourceInlineCompletion: this.inlineCompletion.sourceInlineCompletion,
+			completeBracketPairs: this.inlineCompletion.completeBracketPairs,
+			snippetInfo: this.inlineCompletion.snippetInfo,
 		};
 	}
 }
@@ -623,8 +640,8 @@ export async function provideInlineCompletions(
 					continue;
 				}
 
-				const text =
-					languageConfigurationService && item.completeBracketPairs
+				const textOrSnippet =
+					languageConfigurationService && item.completeBracketPairs && typeof item.text === 'string'
 						? closeBrackets(
 							item.text,
 							range.getStartPosition(),
@@ -633,8 +650,31 @@ export async function provideInlineCompletions(
 						)
 						: item.text;
 
+				let text: string;
+				let snippetInfo: {
+					snippet: string;
+					/* Could be different than the main range */
+					range: Range;
+				}
+					| undefined;
+
+				if (typeof textOrSnippet === 'string') {
+					text = textOrSnippet;
+					snippetInfo = undefined;
+				} else if ('snippet' in textOrSnippet) {
+					const snippet = new SnippetParser().parse(textOrSnippet.snippet);
+					text = snippet.toString();
+					snippetInfo = {
+						snippet: textOrSnippet.snippet,
+						range: range
+					};
+				} else {
+					assertNever(textOrSnippet);
+				}
+
 				const trackedItem: TrackedInlineCompletion = ({
 					text,
+					snippetInfo,
 					range,
 					command: item.command,
 					sourceProvider: result.provider,
@@ -696,5 +736,6 @@ export function minimizeInlineCompletion(model: ITextModel, inlineCompletion: No
 	return {
 		range: Range.fromPositions(start, end),
 		text: inlineCompletion.text.substr(commonPrefixLen, inlineCompletion.text.length - commonPrefixLen - commonSuffixLen),
+		snippetInfo: inlineCompletion.snippetInfo
 	};
 }

src/vs/editor/contrib/inlineCompletions/browser/suggestWidgetInlineCompletionProvider.ts

@@ -228,7 +228,8 @@ function suggestionToSuggestItemInfo(suggestController: SuggestController, posit
 			normalizedInlineCompletion: {
 				// Dummy element, so that space is reserved, but no text is shown
 				range: Range.fromPositions(position, position),
-				text: ''
+				text: '',
+				snippetInfo: undefined,
 			},
 		};
 	}
@@ -260,6 +261,7 @@ function suggestionToSuggestItemInfo(suggestController: SuggestController, posit
 				position.delta(0, -info.overwriteBefore),
 				position.delta(0, Math.max(info.overwriteAfter, 0))
 			),
+			snippetInfo: undefined,
 		}
 	};
 }

src/vs/editor/contrib/inlineCompletions/test/browser/inlineCompletionsProvider.test.ts

@@ -35,7 +35,7 @@ suite('Inline Completions', () => {
 			const options = ['prefix', 'subword'] as const;
 			const result = {} as any;
 			for (const option of options) {
-				result[option] = inlineCompletionToGhostText({ text: suggestion, range }, tempModel, option)?.render(cleanedText, true);
+				result[option] = inlineCompletionToGhostText({ text: suggestion, snippetInfo: undefined, range }, tempModel, option)?.render(cleanedText, true);
 			}
 
 			tempModel.dispose();

src/vs/editor/contrib/inlineCompletions/test/browser/suggestWidgetModel.test.ts

@@ -104,7 +104,7 @@ suite('Suggest Widget Model', () => {
 
 	test('minimizeInlineCompletion', async () => {
 		const model = createTextModel('fun');
-		const result = minimizeInlineCompletion(model, { range: new Range(1, 1, 1, 4), text: 'function' })!;
+		const result = minimizeInlineCompletion(model, { range: new Range(1, 1, 1, 4), text: 'function', snippetInfo: undefined })!;
 
 		assert.deepStrictEqual({
 			range: result.range.toString(),

src/vs/monaco.d.ts

@@ -6263,8 +6263,13 @@ declare namespace monaco.languages {
 		 * The text to insert.
 		 * If the text contains a line break, the range must end at the end of a line.
 		 * If existing text should be replaced, the existing text must be a prefix of the text to insert.
+		 *
+		 * The text can also be a snippet. In that case, a preview with default parameters is shown.
+		 * When accepting the suggestion, the full snippet is inserted.
 		*/
-		readonly text: string;
+		readonly text: string | {
+			snippet: string;
+		};
 		/**
 		 * The range to replace.
 		 * Must begin and end on the same line.

src/vs/workbench/api/common/extHostLanguageFeatures.ts

@@ -1083,7 +1083,7 @@ class InlineCompletionAdapter {
 					throw new Error('text or insertText must be defined');
 				}
 				return ({
-					text: insertText,
+					text: typeof insertText === 'string' ? insertText : { snippet: insertText.value },
 					range: item.range ? typeConvert.Range.from(item.range) : undefined,
 					command,
 					idx: idx,

src/vscode-dts/vscode.proposed.inlineCompletions.d.ts

@@ -102,7 +102,7 @@ declare module 'vscode' {
 		 * Thus, `  B` can be replaced with ` ABC`, effectively removing a whitespace and inserting `A` and `C`.
 		*/
 		// TODO@API support vscode.SnippetString in addition to string, see CompletionItem#insertText
-		insertText?: string;
+		insertText?: string | SnippetString;
 
 		/**
 		 * @deprecated Use `insertText` instead. Will be removed eventually.