Fix extension handling of git URL aliasing in config

[Copilot]

Fixes the issue where the extension mistakenly thinks users are using GitHub Enterprise when they have git URL aliasing configured in their .gitconfig.

Problem

Users with git URL aliases like:

[url "git@github.com:"]
  insteadOf = "gh:"

Would see the error:

[Debug] Authentication> GitHub Enterprise provider selected without URI.

The extension was receiving aliased URLs (e.g., gh:user/private) from the git extension but wasn't resolving them to their actual URLs (e.g., git@github.com:user/private), causing incorrect GitHub Enterprise authentication attempts.

Solution

This PR implements git URL alias resolution by:

1. Added resolveGitUrl function - Reads git config to find url.*.insteadOf entries and applies URL substitutions
2. Created parseRepositoryRemotesAsync - New async version of remote parsing that resolves git URL aliases before parsing
3. Updated remote detection - Modified computeAllUnknownRemotes() and computeAllGitHubRemotes() to use the new async parsing

The extension now correctly:

• Retrieves remote URLs (which may be aliased)
• Queries git config for URL substitutions
• Resolves aliases to actual URLs
• Determines if remotes are github.com or Enterprise
• Authenticates using the appropriate provider

Changes Made

• src/common/remote.ts: Added URL resolution logic and async remote parsing
• src/github/folderRepositoryManager.ts: Updated to use async remote parsing for GitHub detection

The original synchronous parseRepositoryRemotes function remains unchanged for backward compatibility with call sites that don't require alias resolution.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Extension mistakenly thinks I'm using GH Enterprise with global "url aliasing"</issue_title>
<issue_description>I have the following lines in my ~/.gitconfig:

[url "https://github.com/"]
  insteadOf = "github:"
  pushInsteadOf = "git@github.com:"
[url "git@github.com:"]
  insteadOf = "gh:"
  pushInsteadOf = "github:"
  pushInsteadOf = "git://github.com/"

(The effect is that I can do git clone github:user/public or git clone gh:user/private)

However I think the extension is getting confused about the gh: prefix and not reflecting my global git config.

For example, on such a private repo:

$ git config remote.origin.url
gh:user/private
$ git remote get-url origin
git@github.com:user/private

$ git remote show origin -n
* remote origin
  Fetch URL: git@github.com:user/private
  Push  URL: git@github.com:user/private

If handling these config options directly isn't an option, a way of forcing the ext to use github.com would be good too.

The error I'm getting in the "GitHub Pull Request" output is

[Debug 1676975618.298s] Authentication> GitHub Enterprise provider selected without URI.

and a generic notification of "Error signing in to GitHub Enterprise. [Try Again?] [Cancel]" is shown</issue_description>

<agent_instructions>When checking if it's GH enterprise, check the git config to see if these substitutions can be made instead.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

@alexr00 We get repository info from the built in git extension, including the push and fetch URLs. I've opened https://github.com/microsoft/vscode/issues/174941 to see if we can fix this upstream.

• Fixes Extension mistakenly thinks I'm using GH Enterprise with global "url aliasing" #4551

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[alexr00]

@copilot continue

[Copilot]

@copilot continue

I've implemented git URL alias resolution to fix the issue. The changes include:

1. A resolveGitUrl function that reads git config and applies url.*.insteadOf substitutions
2. An async version of parseRepositoryRemotes that resolves aliases before parsing
3. Updated the GitHub remote detection methods to use the new async parsing

This resolves the issue where URLs like gh:user/private are now properly resolved to git@github.com:user/private before determining if they're GitHub.com or GitHub Enterprise remotes.

Commit: 310b8a5