From dafd75966f1f4bd79fe9179e3fd7f3be756613bd Mon Sep 17 00:00:00 2001
From: Tobias Gruetzmacher <tobias-git@23.gs>
Date: Sun, 18 May 2025 22:16:07 +0200
Subject: [PATCH] Add support for a zstandard compressed endpoint

---
 httpbin/core.py                  | 17 +++++++++++++++++
 httpbin/filters.py               | 23 +++++++++++++++++++++++
 httpbin/templates/httpbin.1.html |  1 +
 pyproject.toml                   |  1 +
 tests/test_httpbin.py            |  4 ++++
 5 files changed, 46 insertions(+)

diff --git a/httpbin/core.py b/httpbin/core.py
index e23cc86b..67f2b523 100644
--- a/httpbin/core.py
+++ b/httpbin/core.py
@@ -541,6 +541,23 @@ def view_brotli_encoded_content():
     return jsonify(get_dict("origin", "headers", method=request.method, brotli=True))
 
 
+@app.route("/zstd")
+@filters.zstd
+def view_zstandard_encoded_content():
+    """Returns zstandard-encoded data.
+    ---
+    tags:
+      - Response formats
+    produces:
+      - application/json
+    responses:
+      200:
+        description: zstandard-encoded data.
+    """
+
+    return jsonify(get_dict("origin", "headers", method=request.method, zstandard=True))
+
+
 @app.route("/redirect/<int:n>")
 def redirect_n_times(n):
     """302 Redirects n times.
diff --git a/httpbin/filters.py b/httpbin/filters.py
index 4deeaaad..cc91e46e 100644
--- a/httpbin/filters.py
+++ b/httpbin/filters.py
@@ -11,6 +11,7 @@
 import zlib
 
 import brotlicffi as _brotli
+import zstandard
 
 from six import BytesIO
 from decimal import Decimal
@@ -113,3 +114,25 @@ def brotli(f, *args, **kwargs):
         return data
 
     return deflated_data
+
+@decorator
+def zstd(f, *args, **kwargs):
+    """zstandard Flask Response Decorator"""
+
+    data = f(*args, **kwargs)
+
+    if isinstance(data, Response):
+        content = data.data
+    else:
+        content = data
+
+    deflated_data = zstandard.ZstdCompressor().compress(content)
+
+    if isinstance(data, Response):
+        data.data = deflated_data
+        data.headers['Content-Encoding'] = 'zstd'
+        data.headers['Content-Length'] = str(len(data.data))
+
+        return data
+
+    return deflated_data
diff --git a/httpbin/templates/httpbin.1.html b/httpbin/templates/httpbin.1.html
index ceafd973..84b6c5e0 100644
--- a/httpbin/templates/httpbin.1.html
+++ b/httpbin/templates/httpbin.1.html
@@ -21,6 +21,7 @@ <h2 id="ENDPOINTS">ENDPOINTS</h2>
 <li><a href="{{ url_for('view_gzip_encoded_content') }}" data-bare-link="true"><code>/gzip</code></a> Returns gzip-encoded data.</li>
 <li><a href="{{ url_for('view_deflate_encoded_content') }}" data-bare-link="true"><code>/deflate</code></a> Returns deflate-encoded data.</li>
 <li><a href="{{ url_for('view_brotli_encoded_content') }}" data-bare-link="true"><code>/brotli</code></a> Returns brotli-encoded data.</li>
+<li><a href="{{ url_for('view_zstandard_encoded_content') }}" data-bare-link="true"><code>/zstd</code></a> Returns zstandard-encoded data.</li>
 <li><a href="{{ url_for('view_status_code', codes='418') }}"><code>/status/:code</code></a> Returns given HTTP Status code.</li>
 <li><a href="{{ url_for('response_headers', **{'Content-Type': 'text/plain; charset=UTF-8', 'Server': 'httpbin'}) }}"><code>/response-headers?key=val</code></a> Returns given response headers.</li>
 <li><a href="{{ url_for('redirect_n_times', n=6) }}"><code>/redirect/:n</code></a> 302 Redirects <em>n</em> times.</li>
diff --git a/pyproject.toml b/pyproject.toml
index 894c5509..368c1790 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,6 +39,7 @@ dependencies = [
     'importlib-metadata; python_version<"3.8"',
     "six",
     "werkzeug >= 2.2.2",
+    "zstandard >= 0.20.0",
 ]
 
 [project.optional-dependencies]
diff --git a/tests/test_httpbin.py b/tests/test_httpbin.py
index 6b751245..2cc0b703 100755
--- a/tests/test_httpbin.py
+++ b/tests/test_httpbin.py
@@ -303,6 +303,10 @@ def test_brotli(self):
         response = self.app.get('/brotli')
         self.assertEqual(response.status_code, 200)
 
+    def test_zstandard(self):
+        response = self.app.get('/zstd')
+        self.assertEqual(response.status_code, 200)
+
     def test_bearer_auth(self):
         token = 'abcd1234'
         response = self.app.get(