// Parse commits from commitish string, populating a CommitRange. If a
// single commit is matched, it is paired with its first parent commit
// or resolves to an error
//
// return result.Result<*git.Commit, error>
func ResolveCommits(repo *git.Repository, commitish string) result.Result {
return result.NewResult(repo.Revparse(commitish)).FlatMap(func(value interface{}) result.Result {
spec := value.(*git.Revspec)
return resolveCommit(repo, spec.From()).FlatMap(func(f interface{}) result.Result {
fromCommit := f.(*git.Commit)
return resolveCommit(repo, spec.To()).Analysis(func(t interface{}) result.Result {
toCommit := t.(*git.Commit)
return result.NewSuccess(&CommitRange{fromCommit, toCommit})
}, func(err error) result.Result {
return resolveCommitParent(fromCommit).FlatMap(func(parent interface{}) result.Result {
return result.NewSuccess(&CommitRange{parent.(*git.Commit), fromCommit})
})
})
})
})
}
