add redirect code from @pcdinh

sanic/response.py

@@ -169,3 +169,29 @@ async def file(location, mime_type=None, headers=None):
                         headers=headers,
                         content_type=mime_type,
                         body_bytes=out_stream)
+
+
+def redirect(to, headers=None, status=302,
+             content_type=None):
+    """
+    Aborts execution and causes a 302 redirect (by default).
+
+    :param to: path or fully qualified URL to redirect to
+    :param headers: optional dict of headers to include in the new request
+    :param status: status code (int) of the new request, defaults to 302
+    :param content_type:
+        the content type (string) of the response, defaults to None
+    :returns: the redirecting Response
+    """
+    if not content_type:
+        content_type = "text/html; charset=utf-8"
+
+    headers = headers or {}
+
+    # According to RFC 7231, a relative URI is now permitted.
+    headers['Location'] = to
+
+    return HTTPResponse(
+        status=status,
+        headers=headers,
+        content_type=content_type)

tests/test_requests.py

@@ -1,9 +1,10 @@
 from json import loads as json_loads, dumps as json_dumps
 from sanic import Sanic
-from sanic.response import json, text
+from sanic.response import json, text, redirect
 from sanic.utils import sanic_endpoint_test
 from sanic.exceptions import ServerError
 
+import pytest
 
 # ------------------------------------------------------------ #
 #  GET
@@ -188,3 +189,62 @@ def test_post_form_multipart_form_data():
     request, response = sanic_endpoint_test(app, data=payload, headers=headers)
 
     assert request.form.get('test') == 'OK'
+
+
+@pytest.fixture
+def redirect_app():
+    app = Sanic('test_get_then_redirect_01')
+
+    @app.route('/redirect_init')
+    async def redirect_init(request):
+        return redirect("/redirect_target")
+
+    @app.route('/redirect_init_with_301')
+    async def redirect_init_with_301(request):
+        return redirect("/redirect_target", status=301)
+
+    @app.route('/redirect_target')
+    async def redirect_target(request):
+        return text('OK')
+
+    return app
+
+
+def test_redirect_default_302(redirect_app):
+    """
+    We expect a 302 default status code and the headers to be set.
+    """
+    request, response = sanic_endpoint_test(
+        redirect_app, method="get",
+        uri="/redirect_init",
+        allow_redirects=False)
+
+    assert response.status == 302
+    assert response.headers["Location"] == "/redirect_target"
+    assert response.headers["Content-Type"] == 'text/html; charset=utf-8'
+
+
+def test_redirect_with_301(redirect_app):
+    """
+    Test redirection with a different status code.
+    """
+    request, response = sanic_endpoint_test(
+        redirect_app, method="get",
+        uri="/redirect_init_with_301",
+        allow_redirects=False)
+
+    assert response.status == 301
+    assert response.headers["Location"] == "/redirect_target"
+
+
+def test_get_then_redirect_follow_redirect(redirect_app):
+    """
+    With `allow_redirects` we expect a 200.
+    """
+    response = sanic_endpoint_test(
+        redirect_app, method="get",
+        uri="/redirect_init", gather_request=False,
+        allow_redirects=True)
+
+    assert response.status == 200
+    assert response.text == 'OK'