Add NonGitRepository error code and detection in set_project_active

Co-authored-by: Byron <[email protected]>

Author: Copilot

apps/desktop/src/lib/error/knownErrors.ts

@@ -8,7 +8,8 @@ export enum Code {
 	ProjectMissing = 'errors.projects.missing',
 	SecretKeychainNotFound = 'errors.secret.keychain_notfound',
 	MissingLoginKeychain = 'errors.secret.missing_login_keychain',
-	GitHubTokenExpired = 'errors.github.expired_token'
+	GitHubTokenExpired = 'errors.github.expired_token',
+	NonGitRepository = 'errors.projects.not_git_repository'
 }
 
 export const KNOWN_ERRORS: Record<string, string> = {
@@ -34,5 +35,8 @@ With \`seahorse\` or equivalent, create a \`Login\` password store, right click
 	`,
 	[Code.GitHubTokenExpired]: `
 Your GitHub token appears expired, please check your settings!
+	`,
+	[Code.NonGitRepository]: `
+The selected directory is not a Git repository. Would you like to initialize a Git repository in this directory?
 	`
 };

crates/gitbutler-error/src/error.rs

@@ -139,6 +139,7 @@ pub enum Code {
     SecretKeychainNotFound,
     MissingLoginKeychain,
     GitForcePushProtection,
+    NonGitRepository,
 }
 
 impl std::fmt::Display for Code {
@@ -157,6 +158,7 @@ impl std::fmt::Display for Code {
             Code::SecretKeychainNotFound => "errors.secret.keychain_notfound",
             Code::MissingLoginKeychain => "errors.secret.missing_login_keychain",
             Code::GitForcePushProtection => "errors.git.force_push_protection",
+            Code::NonGitRepository => "errors.projects.not_git_repository",
         };
         f.write_str(code)
     }

crates/gitbutler-tauri/src/projects.rs

@@ -69,6 +69,10 @@ pub fn set_project_active(
             let err = anyhow::Error::from(err);
             if code == git2::ErrorCode::Owner {
                 err.context(gitbutler_error::error::Code::RepoOwnership)
+            } else if code == git2::ErrorCode::NotFound {
+                // When git2::Repository::open fails with NotFound, it likely means the directory
+                // is not a git repository, so we attach our custom error code.
+                err.context(gitbutler_error::error::Code::NonGitRepository)
             } else {
                 err
             }