France certainly doesn't have strong unions, at least in the private sector.

We indeed have very vocal unions in the public sector (administration, public services), that can basically stop the country when something they dislike happens. They are basically the reason why teachers, railroad workers, judges and all are always on strike.
Let me say that I don't think this is how unions should work. They should promote dialogue and not simply decide to block the country whenever they want to. On the other hand, french governments most of the time aren't really interested in discussion and rather try to pass their laws and reforms without any talk.

But outside of that, in the private sector (where unions are the most needed, by far), there's basically no or little unions left since the 90's and the downfall of the communist party.
If you want to see a country with strong and representative unions, you should rather look at Norway, Sweden or even Germany.