Proper way to use `RequirePackage` and avoid option clash

Question

I'm developing a small LaTeX library that requires hyperref to work, but I'm facing 2 problems:

1. I think that hyperref should usually be loaded at the very end. However, if I put a \RequirePackage{hyperref} in my library, will it be loaded at the beginning? If the user also adds \usepackage{hyperref} at the end, will it solve the problem, or will it be ignored as hyperref was already loaded before?

2. When the user adds options to the hyperref package, it breaks with an error:

   ERROR: LaTeX Error: Option clash for package hyperref.

So what is the proper way to say "my package requires hyperref", but still allow the user to overwrite the hyperref options/make sure it's loaded last?

Thanks!

MWE:

\documentclass{article}
\usepackage{filecontents}
\begin{filecontents}[overwrite]{mypackage.sty}
  \NeedsTeXFormat{LaTeX2e}
  \ProvidesPackage{mypackage}[2020/07/13 A dummy package]
  \RequirePackage{hyperref}
\end{filecontents}

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[francais]{babel}

\usepackage{mypackage}
\usepackage[colorlinks]{hyperref}

\begin{document}
Hello
\end{document}

Answer 1

The Option Clash error only happens when the options used at the second \usepackage are not empty and differ from the first option list, so you can defer loading hyperref at the very end of the preamble (for example, by using etoolbox's \AtEndPreamble) and load it without options. In this case, if the user doesn't load hyperref, your package does at the end of the preamble. If the user does load hyperref with options, then your \RequirePackage{hyperref} line won't raise an error because no option was requested. You can pass options to hyperref using \PassOptionsToPackage{hidelinks}{hyperref}:

\documentclass{article}
\begin{filecontents}[overwrite]{mypackage.sty}
  \NeedsTeXFormat{LaTeX2e}
  \ProvidesPackage{mypackage}[2020/07/13 A dummy package]
  \RequirePackage{etoolbox}
  % Any option your package wants:
  % \PassOptionsToPackage{hidelinks}{hyperref}
  \AtEndPreamble{%
    \RequirePackage{hyperref}}%
\end{filecontents}

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[francais]{babel}

\usepackage{mypackage}
\usepackage[colorlinks]{hyperref}

\begin{document}
Hello
\end{document}

But this will be problematic, for example, with cleveref, or other packages that must be loaded after hyperref: the user will have to load hyperref explicitly before loading cleveref, otherwise things won't work properly.