Don't preserve old repository on URL change

The library maintainers may request a change to the repository URL in the library registration data.

This operation is performed by the backend maintainer via the command:

libraries-repository-engine modify --repo-url

Previously, this command did three things:

- Update the DB entry for the library
- Move the release archives to the new location (the storage structure is based on the repository URL for some reason)
- Move the cached library repository clone to the new location

Problem
-------

The last of these is problematic because the remote of that repository is still configured for the original URL, meaning
the fetch done during the `sync` command execution were still done against the old URL.

This bug is not noticeable under either of the following scenarios:

The repository was renamed or transferred
=========================================

This produces a redirect from the old URL to the new one, so the fetch is done from the intended repo despite the
outdated remote configuration.

The original repository was deleted
===================================

If a fetch fails, the engine deletes the repository and clones from the URL in the DB. The newly cloned repo will have
the correct remote configuration.

The bug is noticeable under the following scenario:

The original repository still exists
====================================

The sync process continues to fetch from the old URL.

Solution
--------

Change the `modify --repo-url` command behavior to delete the cached library repository clone.

The repository will be cloned from the updated URL on the next run of the `sync` command.

Author: per1234

internal/command/modify/modify.go

@@ -163,32 +163,18 @@ func modifyRepositoryURL(newRepositoryURL string) error {
 
 	fmt.Printf("Changing URL of library %s from %s to %s\n", libraryName, oldRepositoryURL, newRepositoryURL)
 
-	// Move the library Git clone to the new path.
-	gitClonePath := func(url string) (*paths.Path, error) {
-		libraryRegistration := libraries.Repo{URL: url}
-		gitCloneSubfolder, err := libraryRegistration.AsFolder()
-		if err != nil {
-			return nil, err
-		}
-
-		return paths.New(config.GitClonesFolder, gitCloneSubfolder), nil
-	}
-	oldGitClonePath, err := gitClonePath(oldRepositoryURL)
+	// Remove the library Git clone folder. It will be cloned from the new URL on the next sync.
+	libraryRegistration := libraries.Repo{URL: libraryData.Repository}
+	gitCloneSubfolder, err := libraryRegistration.AsFolder()
 	if err != nil {
 		return err
 	}
-	newGitClonePath, err := gitClonePath(newRepositoryURL)
-	if err != nil {
-		return err
-	}
-	if err := newGitClonePath.Parent().MkdirAll(); err != nil {
-		return fmt.Errorf("While creating new library Git clone path: %w", err)
-	}
-	if err := backup.Backup(oldGitClonePath); err != nil {
+	gitClonePath := paths.New(config.GitClonesFolder, gitCloneSubfolder)
+	if err := backup.Backup(gitClonePath); err != nil {
 		return fmt.Errorf("While backing up library's Git clone: %w", err)
 	}
-	if err := oldGitClonePath.Rename(newGitClonePath); err != nil {
-		return fmt.Errorf("While moving library's Git clone: %w", err)
+	if err := gitClonePath.RemoveAll(); err != nil {
+		return fmt.Errorf("While removing library's Git clone: %w", err)
 	}
 
 	// Update the library repository URL in the database.

tests/test_modify.py

@@ -227,9 +227,6 @@ def test_repo_url(
     new_library_release_archives_folder = pathlib.Path(configuration.data["LibrariesFolder"]).joinpath(
         new_host, new_owner
     )
-    new_git_clone_path = pathlib.Path(configuration.data["GitClonesFolder"]).joinpath(
-        new_host, new_owner, new_repo_name
-    )
     # The "canary" library is not modified and so all its content should remain unchanged after running the command
     canary_name = "ArduinoIoTCloudBearSSL"
     sanitized_canary_name = "ArduinoIoTCloudBearSSL"
@@ -281,7 +278,6 @@ def get_release_archive_url(name, version):
         raise
 
     assert old_git_clone_path.exists()
-    assert not new_git_clone_path.exists()
     assert canary_git_clone_path.exists()
     assert get_library_repo_url(name=name) != new_repo_url
     assert get_library_repo_url(name=canary_name) == canary_repo_url
@@ -314,7 +310,6 @@ def get_release_archive_url(name, version):
 
     # Verify the effect of the command was as expected
     assert not old_git_clone_path.exists()
-    assert new_git_clone_path.exists()
     assert canary_release_archive_path.exists()
     assert canary_git_clone_path.exists()
     assert get_library_repo_url(name=name) == new_repo_url