refactor(git-provider): move IsGitRepo to GitManager, refactor NewGitRepoCommand

src/ModuleCore/Git/GitManager.cs

@@ -145,6 +145,73 @@ public class GitManager
 		throw new Exception($"No git repo has been registered with the name {registeredName}");
 	}
 
+	/// <summary>
+	/// Returns the git root directory for any nested directory if git rev-parse --show-toplevel returns a value.
+	/// </summary>
+	/// <param name="path">Path to check if it or any of its parents contain a git repository</param>
+	/// <returns></returns>
+	/// <exception cref="Exception">
+	/// Git fails to start, returns an error (ie: the directory is not in a git repo), or the git process does not return
+	/// any output or error.
+	/// </exception>
+	public static ParsedGitFolderDetails IsGitRepo(string path)
+	{
+		_debugWriterDelegate?.Invoke("Checking if current directory is a git repository...");
+
+		var ps = new ProcessStartInfo("git",
+			["-C", path, "rev-parse", "--show-toplevel"])
+		{
+			RedirectStandardOutput = true,
+			RedirectStandardError = true,
+		};
+
+		// If the user doesn't have git on their path, this will throw an exception that I don't have to do anything
+		// special with, it'll be unhandled and powershell will handle it
+		var gitProcess = Process.Start(ps);
+
+		// This probably shouldn't be possible? Not really sure of the conditions where the process could be started
+		// but return null, but I'm going to consider that unrecoverable error territory
+		if (gitProcess is null)
+		{
+			throw new Exception("git failed to start")
+			{
+				Source = "git-process",
+			};
+		}
+
+		gitProcess.WaitForExit();
+
+		if (!gitProcess.StandardOutput.EndOfStream)
+		{
+			var directory = gitProcess.StandardOutput.ReadToEnd();
+			// Gotta trim what we get as it might already have a newline character at the end
+			var dirInfo = new DirectoryInfo(directory.Trim());
+
+			_debugWriterDelegate?.Invoke("...location is a git repo (duh).");
+
+			var repoFolderInfo = new ParsedGitFolderDetails
+			{
+				Directory = dirInfo.FullName,
+				Folder = dirInfo.Name,
+			};
+
+			return repoFolderInfo;
+		}
+
+		if (!gitProcess.StandardError.EndOfStream)
+		{
+			throw new Exception(gitProcess.StandardError.ReadToEnd())
+			{
+				Source = "git-not-found",
+			};
+		}
+
+		throw new Exception("Unable to determine if directory is repository: git command returned no output or errors.")
+		{
+			Source = "git-parse-failed",
+		};
+	}
+
 	/// <summary>
 	/// Registers an output for debug output. <see cref="ClearDebugWriter" /> should be called as soon as the need for output
 	/// is no longer needed.
@@ -234,4 +301,20 @@ public class GitManager
 			return _currentBranch.Trim();
 		}
 	}
+}
+
+/// <summary>
+/// The directory details of the directory returned from git rev-parse --show-toplevel
+/// </summary>
+public class ParsedGitFolderDetails
+{
+	/// <summary>
+	/// The full path to the top level folder containing a git repository
+	/// </summary>
+	public string Directory { get; init; } = null!;
+
+	/// <summary>
+	/// The last folder name of the directory
+	/// </summary>
+	public string Folder { get; init; } = null!;
 }