HTTP-HTTPS redirection

With the irule when my client goes to www.x.fr/y/z it remains in HTTP thats OK. When accessing www.x.fr/y he is redirected to HTTPS thats OK but when going to www.x.fr/y/z it remains in HTTP whereas it should have been redirected to HTTPS.

This is a little confusing. According to your original statements, "www.x.fr/y/z" should be HTTP. Did you mean that from "www.x.fr/y/" to "www.x.fr/y/z" it should redirect FROM HTTPS to HTTP?

If the above is true, then you need to build your logic from MOST explicit to LEAST explicit. Here's a switch structure that, I think, does essentially what you're asking for.

when HTTP_REQUEST {
    if { [string tolower [HTTP::host]] equals "test.domain.com" } {
        switch -glob [string tolower [HTTP::uri]] {
            "/y/z*" {
                if { [TCP::local_port] ne "80" } { HTTP::redirect "http://[HTTP::host][HTTP::uri]" }
            }
            "/y/*" {
                if { [TCP::local_port] ne "443" } { HTTP::redirect "https://[HTTP::host][HTTP::uri]" }
            }
            "/y*" {
                if { [TCP::local_port] ne "443" } { HTTP::redirect "https://[HTTP::host][HTTP::uri]" }
            }
            "/*" {
                if { [TCP::local_port] ne "80" } { HTTP::redirect "http://[HTTP::host][HTTP::uri]" }
             }
            default { drop }
        }
    }
}