MITM rule for bigger screen

metaview.py

# Usage: mitmdump -s "modify_response_body.py mitmproxy bananas"
# (this script works best with --anticache)
from libmproxy.models import decoded

script = '''
<script type="text/javascript">
(function() {
    var width = 400;

    big();

    function big() {
        width += 40;
        var view = document.querySelector("meta[name=viewport]") || document.createElement('meta');
        view.setAttribute("name", "viewport");
        view.setAttribute("content", "width=" + width);
        document.head.appendChild(view);
        }

    function small() {
        width -= 40;
        var view = document.querySelector("meta[name=viewport]") || document.createElement('meta');
        view.setAttribute("name", "viewport");
        view.setAttribute("content", "width=" + width);
        document.head.appendChild(view);
        }

    document.addEventListener('DOMContentLoaded', function() {
        var div = document.createElement('div')
        var plus = document.createElement('span');
        var minus = document.createElement('span');

        plus.innerText = "+";
        plus.style.cssText = ["",
            "color: white",
            "background-color: rgba(0, 0, 255, 0.5)",
            "position: fixed",
            "bottom: 70px",
            "right: 20px",
            "font-family: monospace",
            "font-size: 28px",
            "line-height: 40px",
            "width: 40px",
            "text-align: center",
            ""].join(";");
        plus.addEventListener("click", small);

        minus.innerText = "-";
        minus.style.cssText = ["",
            "color: white",
            "background-color: rgba(0, 0, 255, 0.5)",
            "position: fixed",
            "bottom: 20px",
            "right: 20px",
            "font-family: monospace",
            "font-size: 28px",
            "line-height: 40px",
            "width: 40px",
            "text-align: center",
            ""].join(";")
        minus.addEventListener("click", big);

        div.appendChild(minus);
        div.appendChild(plus);
        document.body.appendChild(div);
        });
    })();
</script>
'''

def response(context, flow):
	with decoded(flow.response):  # automatically decode gzipped responses.
		flow.response.content = flow.response.content.replace(
			'</head>',
			script + '</head>')