Support emoji completions in review comments (#8009)

* Support emoji completions in review comments

* PR feedback

* Improved logic

Author: kycutler

src/common/emoji.ts

@@ -13,13 +13,14 @@ const emojiRegex = /:([-+_a-z0-9]+):/g;
 let emojiMap: Record<string, string> | undefined;
 let emojiMapPromise: Promise<void> | undefined;
 
-export async function ensureEmojis(context: ExtensionContext) {
+export async function ensureEmojis(context: ExtensionContext): Promise<Record<string, string>> {
 	if (emojiMap === undefined) {
 		if (emojiMapPromise === undefined) {
 			emojiMapPromise = loadEmojiMap(context);
 		}
 		await emojiMapPromise;
 	}
+	return emojiMap!;
 }
 
 async function loadEmojiMap(context: ExtensionContext) {

src/extension.ts

@@ -43,6 +43,7 @@ import { UriHandler } from './uriHandler';
 import { CommentDecorationProvider } from './view/commentDecorationProvider';
 import { CompareChanges } from './view/compareChangesTreeDataProvider';
 import { CreatePullRequestHelper } from './view/createPullRequestHelper';
+import { EmojiCompletionProvider } from './view/emojiCompletionProvider';
 import { FileTypeDecorationProvider } from './view/fileTypeDecorationProvider';
 import { GitHubCommitFileSystemProvider } from './view/githubFileContentProvider';
 import { getInMemPRFileSystemProvider } from './view/inMemPRContentProvider';
@@ -181,6 +182,12 @@ async function init(
 	const reviewsManager = new ReviewsManager(context, reposManager, reviewManagers, prsTreeModel, tree, changesTree, telemetry, credentialStore, git, copilotRemoteAgentManager, notificationsManager);
 	context.subscriptions.push(reviewsManager);
 
+	context.subscriptions.push(vscode.languages.registerCompletionItemProvider(
+		{ scheme: Schemes.Comment },
+		new EmojiCompletionProvider(context),
+		':'
+	));
+
 	git.onDidChangeState(() => {
 		Logger.appendLine(`Git initialization state changed: state=${git.state}`, ACTIVATION);
 		reviewsManager.reviewManagers.forEach(reviewManager => reviewManager.updateState(true));

src/view/emojiCompletionProvider.ts

@@ -0,0 +1,61 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+import { ensureEmojis } from '../common/emoji';
+import { Schemes } from '../common/uri';
+
+export class EmojiCompletionProvider implements vscode.CompletionItemProvider {
+	private _emojiCompletions: vscode.CompletionItem[] = [];
+
+	constructor(private _context: vscode.ExtensionContext) {
+		void this.buildEmojiCompletions();
+	}
+
+	private async buildEmojiCompletions(): Promise<void> {
+		const emojis = await ensureEmojis(this._context);
+
+		for (const [name, emoji] of Object.entries(emojis)) {
+			const completionItem = new vscode.CompletionItem({ label: emoji, description: `:${name}:` }, vscode.CompletionItemKind.Text);
+			completionItem.filterText = `:${name}:`;
+			completionItem.sortText = name;
+			this._emojiCompletions.push(completionItem);
+		}
+	}
+
+	provideCompletionItems(
+		document: vscode.TextDocument,
+		position: vscode.Position,
+		_token: vscode.CancellationToken,
+		context: vscode.CompletionContext
+	): vscode.ProviderResult<vscode.CompletionItem[] | vscode.CompletionList> {
+		// Only provide completions for comment documents
+		if (document.uri.scheme !== Schemes.Comment) {
+			return [];
+		}
+
+		const word = document.getWordRangeAtPosition(position, /:([-+_a-z0-9]+:?)?/i);
+		if (!word) {
+			return [];
+		}
+
+		// If invoked by trigger charcter, ignore if this is the start of an emoji (single ':') and there is no preceding space
+		if (context.triggerKind === vscode.CompletionTriggerKind.TriggerCharacter) {
+			if (word.end.character - word.start.character === 1 && word.start.character > 0) {
+				const charBefore = document.getText(new vscode.Range(word.start.translate(0, -1), word.start));
+				if (!/\s/.test(charBefore)) {
+					return [];
+				}
+			}
+		}
+
+		// Update the range on cached items directly
+		for (const item of this._emojiCompletions) {
+			item.range = word;
+		}
+
+		return new vscode.CompletionList(this._emojiCompletions, false);
+	}
+}