GET /svg

# SVG is XML; parse with defusedxml for safety on untrusted input.
# cairosvg and other rasterisers behave differently on each mode —
# external-image-ref typically hangs while fetching, circular-use
# may OOM, bad-namespace yields a blank raster.
import urllib.request
from defusedxml import ElementTree as DET

raw = urllib.request.urlopen("https://chaos.catastrophic.io/svg?mode=mismatched-tags").read()
try:
    root = DET.fromstring(raw)
    print(f"Root tag: {root.tag}")
except Exception as e:
    print(f"Parse error: {type(e).__name__}: {e}")

// Browsers tolerate a lot of malformed SVG when used as ;
// serving the same bytes to DOMParser as image/svg+xml is stricter.
const res = await fetch("https://chaos.catastrophic.io/svg?mode=mismatched-tags");
const raw = await res.text();
console.log("Mode:", res.headers.get("X-Chaos-Svg-Mode"));
const doc = new DOMParser().parseFromString(raw, "image/svg+xml");
const err = doc.querySelector("parsererror");
console.log("Parsed clean:", !err);
if (err) console.log("Parser said:", err.textContent);

package main

import (
    "encoding/xml"
    "fmt"
    "io"
    "net/http"
    "strings"
)

func main() {
    resp, _ := http.Get("https://chaos.catastrophic.io/svg?mode=mismatched-tags")
    defer resp.Body.Close()
    raw, _ := io.ReadAll(resp.Body)
    fmt.Println("Mode:", resp.Header.Get("X-Chaos-Svg-Mode"))

    // SVG is XML; encoding/xml refuses DOCTYPE entirely so the
    // billion-laughs-style modes never reach element parsing.
    var v any
    dec := xml.NewDecoder(strings.NewReader(string(raw)))
    err := dec.Decode(&v)
    fmt.Println("Parse error:", err)
}

// Cargo.toml: reqwest = { version = "0.12", features = ["blocking"] }
//             resvg = "0.43" (or usvg = "0.43" for parse-only)
use usvg::{Options, Tree};
fn main() -> Result<(), Box> {
    let raw = reqwest::blocking::get("https://chaos.catastrophic.io/svg?mode=mismatched-tags")?.bytes()?;
    match Tree::from_data(&raw, &Options::default()) {
        Ok(tree) => println!("Parsed: {}x{}", tree.size().width(), tree.size().height()),
        Err(e)   => eprintln!("Refused: {e}"),
    }
    Ok(())
}

// Requires Apache Batik (org.apache.xmlgraphics:batik-transcoder).
// Batik resolves external references by default; toggle via the
// ALLOW_EXTERNAL_RESOURCES_KEY transcoding hint when handling
// untrusted SVG.
import org.apache.batik.transcoder.*;
import org.apache.batik.transcoder.image.PNGTranscoder;
import java.net.URI;
import java.net.http.*;
import java.io.*;

public class SvgChaos {
    public static void main(String[] args) throws Exception {
        var client = HttpClient.newHttpClient();
        var req = HttpRequest.newBuilder(URI.create("https://chaos.catastrophic.io/svg?mode=mismatched-tags")).build();
        var resp = client.send(req, HttpResponse.BodyHandlers.ofInputStream());
        try {
            var t = new PNGTranscoder();
            t.transcode(new TranscoderInput(resp.body()), new TranscoderOutput(OutputStream.nullOutputStream()));
            System.out.println("Rasterised clean");
        } catch (Exception e) {
            System.err.println("Refused: " + e.getMessage());
        }
    }
}

// Svg.NET library; parsing only (no raster).
using Svg;
using var client = new HttpClient();
var raw = await client.GetStreamAsync("https://chaos.catastrophic.io/svg?mode=mismatched-tags");
try {
    var doc = SvgDocument.Open(raw);
    Console.WriteLine($"Parsed: {doc.Width}x{doc.Height}");
} catch (Exception e) {
    Console.Error.WriteLine($"Refused: {e.Message}");
}

# Nokogiri can parse SVG as XML; for raster use rsvg / librsvg
# bindings if you need to test rendering behaviour.
require "net/http"
require "nokogiri"

resp = Net::HTTP.get_response(URI("https://chaos.catastrophic.io/svg?mode=mismatched-tags"))
raw  = resp.body
puts "Mode: #{resp['X-Chaos-Svg-Mode']}"
doc = Nokogiri::XML(raw) { |c| c.strict.nonet }
puts "Errors: #{doc.errors}"
puts "Root: #{doc.root && doc.root.name}"

# PowerShell has no built-in SVG renderer; parse as XML and inspect
# the structure. For actual rasterisation, shell out to Inkscape or
# rsvg-convert if installed.
$resp = Invoke-WebRequest -Uri 'https://chaos.catastrophic.io/svg?mode=mismatched-tags' -SkipHttpErrorCheck
$resp.Headers['X-Chaos-Svg-Mode']
try {
    [xml]$svg = $resp.Content
    "Root: $($svg.DocumentElement.LocalName) (namespace: $($svg.DocumentElement.NamespaceURI))"
} catch {
    "Refused: $($_.Exception.Message)"
}