Replace file system provider with webview for empty commits

- Removed EmptyCommitFileSystemProvider and related URI scheme
- Created showEmptyCommitWebview() function with centered message
- Updated openCommitChanges() to accept extensionUri and show webview
- Styled webview to display message centered similar to GitHub.com

Co-authored-by: alexr00 <38270282+alexr00@users.noreply.github.com>

Author: Copilot

src/common/uri.ts

@@ -117,14 +117,6 @@ export function toGitHubCommitUri(fileName: string, params: GitHubCommitUriParam
 	});
 }
 
-export function toEmptyCommitUri(commitSha: string): vscode.Uri {
-	return vscode.Uri.from({
-		scheme: Schemes.EmptyCommit,
-		path: `/commit-${commitSha.substring(0, 7)}.txt`,
-		query: commitSha
-	});
-}
-
 const ImageMimetypes = ['image/png', 'image/gif', 'image/jpeg', 'image/webp', 'image/tiff', 'image/bmp'];
 // Known media types that VS Code can handle: https://github.com/microsoft/vscode/blob/a64e8e5673a44e5b9c2d493666bde684bd5a135c/src/vs/base/common/mime.ts#L33-L84
 export const KnownMediaExtensions = [
@@ -758,8 +750,7 @@ export enum Schemes {
 	Repo = 'repo', // New issue file for passing data
 	Git = 'git', // File content from the git extension
 	PRQuery = 'prquery', // PR query tree item
-	GitHubCommit = 'githubcommit', // file content from GitHub for a commit
-	EmptyCommit = 'emptycommit' // Empty commit placeholder file
+	GitHubCommit = 'githubcommit' // file content from GitHub for a commit
 }
 
 export function resolvePath(from: vscode.Uri, to: string) {

src/extension.ts

@@ -44,7 +44,6 @@ import { CommentDecorationProvider } from './view/commentDecorationProvider';
 import { CompareChanges } from './view/compareChangesTreeDataProvider';
 import { CreatePullRequestHelper } from './view/createPullRequestHelper';
 import { EmojiCompletionProvider } from './view/emojiCompletionProvider';
-import { EmptyCommitFileSystemProvider } from './view/emptyCommitFileSystemProvider';
 import { FileTypeDecorationProvider } from './view/fileTypeDecorationProvider';
 import { GitHubCommitFileSystemProvider } from './view/githubFileContentProvider';
 import { getInMemPRFileSystemProvider } from './view/inMemPRContentProvider';
@@ -501,8 +500,6 @@ async function deferredActivate(context: vscode.ExtensionContext, showPRControll
 	context.subscriptions.push(vscode.workspace.registerFileSystemProvider(Schemes.Pr, inMemPRFileSystemProvider, { isReadonly: readOnlyMessage }));
 	const githubFilesystemProvider = new GitHubCommitFileSystemProvider(reposManager, apiImpl, credentialStore);
 	context.subscriptions.push(vscode.workspace.registerFileSystemProvider(Schemes.GitHubCommit, githubFilesystemProvider, { isReadonly: new vscode.MarkdownString(vscode.l10n.t('GitHub commits cannot be edited')) }));
-	const emptyCommitFileSystemProvider = new EmptyCommitFileSystemProvider();
-	context.subscriptions.push(vscode.workspace.registerFileSystemProvider(Schemes.EmptyCommit, emptyCommitFileSystemProvider, { isReadonly: true }));
 
 	await init(context, apiImpl, credentialStore, repositories, prTree, liveshareApiPromise, showPRController, reposManager, createPrHelper, copilotRemoteAgentManager, themeWatcher, prsTreeModel);
 	return apiImpl;

src/github/emptyCommitWebview.ts

@@ -0,0 +1,65 @@
+/*---------------------------------------------------------------------------------------------
+ *  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';
+
+/**
+ * Opens a webview panel to display a message for an empty commit.
+ * The message is centered and styled similar to GitHub.com.
+ */
+export function showEmptyCommitWebview(extensionUri: vscode.Uri, commitSha: string): void {
+	const panel = vscode.window.createWebviewPanel(
+		'emptyCommit',
+		vscode.l10n.t('Commit {0}', commitSha.substring(0, 7)),
+		vscode.ViewColumn.Active,
+		{
+			enableScripts: false,
+			localResourceRoots: []
+		}
+	);
+
+	panel.webview.html = getEmptyCommitHtml();
+}
+
+function getEmptyCommitHtml(): string {
+	return `<!DOCTYPE html>
+<html lang="en">
+<head>
+	<meta charset="UTF-8">
+	<meta name="viewport" content="width=device-width, initial-scale=1.0">
+	<title>Empty Commit</title>
+	<style>
+		body {
+			margin: 0;
+			padding: 0;
+			height: 100vh;
+			display: flex;
+			align-items: center;
+			justify-content: center;
+			font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
+			background-color: var(--vscode-editor-background);
+			color: var(--vscode-editor-foreground);
+		}
+		.container {
+			text-align: center;
+			padding: 2rem;
+		}
+		.message {
+			font-size: 1.2rem;
+			line-height: 1.6;
+			color: var(--vscode-descriptionForeground);
+		}
+	</style>
+</head>
+<body>
+	<div class="container">
+		<div class="message">
+			No changes to show.<br>
+			This commit has no content.
+		</div>
+	</div>
+</body>
+</html>`;
+}

src/github/pullRequestModel.ts

@@ -11,6 +11,7 @@ import * as vscode from 'vscode';
 import { OctokitCommon } from './common';
 import { ConflictResolutionModel } from './conflictResolutionModel';
 import { CredentialStore } from './credentials';
+import { showEmptyCommitWebview } from './emptyCommitWebview';
 import { FolderRepositoryManager } from './folderRepositoryManager';
 import { GitHubRepository, GraphQLError, GraphQLErrorType } from './githubRepository';
 import {
@@ -89,7 +90,7 @@ import { Remote } from '../common/remote';
 import { DEFAULT_MERGE_METHOD, PR_SETTINGS_NAMESPACE } from '../common/settingKeys';
 import { ITelemetry } from '../common/telemetry';
 import { ClosedEvent, EventType, ReviewEvent, TimelineEvent } from '../common/timelineEvent';
-import { resolvePath, Schemes, toEmptyCommitUri, toGitHubCommitUri, toPRUri, toReviewUri } from '../common/uri';
+import { resolvePath, Schemes, toGitHubCommitUri, toPRUri, toReviewUri } from '../common/uri';
 import { formatError, isDescendant } from '../common/utils';
 import { InMemFileChangeModel, RemoteFileChangeModel } from '../view/fileChangeModel';
 
@@ -1465,7 +1466,7 @@ export class PullRequestModel extends IssueModel<PullRequest> implements IPullRe
 		return vscode.commands.executeCommand('vscode.changes', vscode.l10n.t('Changes in Pull Request #{0}', pullRequestModel.number), args);
 	}
 
-	static async openCommitChanges(githubRepository: GitHubRepository, commitSha: string) {
+	static async openCommitChanges(extensionUri: vscode.Uri, githubRepository: GitHubRepository, commitSha: string) {
 		try {
 			const parentCommit = await githubRepository.getCommitParent(commitSha);
 			if (!parentCommit) {
@@ -1475,9 +1476,9 @@ export class PullRequestModel extends IssueModel<PullRequest> implements IPullRe
 
 			const changes = await githubRepository.compareCommits(parentCommit, commitSha);
 			if (!changes?.files || changes.files.length === 0) {
-				// Open a file showing the empty commit message instead of showing a notification
-				const emptyCommitUri = toEmptyCommitUri(commitSha);
-				return vscode.window.showTextDocument(emptyCommitUri, { preview: false });
+				// Show a webview with the empty commit message instead of a notification
+				showEmptyCommitWebview(extensionUri, commitSha);
+				return;
 			}
 
 			// Create URI pairs for the multi diff editor using review scheme

src/github/pullRequestOverview.ts

@@ -554,7 +554,7 @@ export class PullRequestOverviewPanel extends IssueOverviewPanel<PullRequestMode
 	private async openCommitChanges(message: IRequestMessage<OpenCommitChangesArgs>): Promise<void> {
 		try {
 			const { commitSha } = message.args;
-			await PullRequestModel.openCommitChanges(this._item.githubRepository, commitSha);
+			await PullRequestModel.openCommitChanges(this._extensionUri, this._item.githubRepository, commitSha);
 			this._replyMessage(message, {});
 		} catch (error) {
 			Logger.error(`Failed to open commit changes: ${formatError(error)}`, PullRequestOverviewPanel.ID);