AMP Bench warns about If-Modified-Since as not supported, but it is

[xavierleune]

Hi,

I think there is an error about "if-modified-since" validation. As far as I understand, ampbench is searching for a response header "if-modified-since" to mark the status as passed, but if-modified-since is only a request header, so this check does not make any sense.

You can reproduce this issue with the following url: https://www.journaldunet.com/economie/transport/1439209-uber-blablalines-assistant-sncf-agregateur-mobilites/

A better way to validate the if-modified-since support is to check the cachability response headers + the Last-Modified header.

Thanks