JSON encoder change via app (#2055)

tests/test_blueprint_group.py

@@ -1,8 +1,8 @@
 from pytest import raises
 
 from sanic.app import Sanic
-from sanic.blueprints import Blueprint
 from sanic.blueprint_group import BlueprintGroup
+from sanic.blueprints import Blueprint
 from sanic.request import Request
 from sanic.response import HTTPResponse, text
 

tests/test_json_encoding.py

@@ -0,0 +1,92 @@
+import sys
+
+from dataclasses import asdict, dataclass
+from functools import partial
+from json import dumps as sdumps
+
+import pytest
+
+
+try:
+    from ujson import dumps as udumps
+
+    NO_UJSON = False
+    DEFAULT_DUMPS = udumps
+except ModuleNotFoundError:
+    NO_UJSON = True
+    DEFAULT_DUMPS = partial(sdumps, separators=(",", ":"))
+
+from sanic import Sanic
+from sanic.response import BaseHTTPResponse, json
+
+
+@dataclass
+class Foo:
+    bar: str
+
+    def __json__(self):
+        return udumps(asdict(self))
+
+
+@pytest.fixture
+def foo():
+    return Foo(bar="bar")
+
+
+@pytest.fixture
+def payload(foo):
+    return {"foo": foo}
+
+
+@pytest.fixture(autouse=True)
+def default_back_to_ujson():
+    yield
+    BaseHTTPResponse._dumps = DEFAULT_DUMPS
+
+
+def test_change_encoder():
+    Sanic("...", dumps=sdumps)
+    assert BaseHTTPResponse._dumps == sdumps
+
+
+def test_change_encoder_to_some_custom():
+    def my_custom_encoder():
+        return "foo"
+
+    Sanic("...", dumps=my_custom_encoder)
+    assert BaseHTTPResponse._dumps == my_custom_encoder
+
+
+@pytest.mark.skipif(NO_UJSON is True, reason="ujson not installed")
+def test_json_response_ujson(payload):
+    """ujson will look at __json__"""
+    response = json(payload)
+    assert response.body == b'{"foo":{"bar":"bar"}}'
+
+    with pytest.raises(
+        TypeError, match="Object of type Foo is not JSON serializable"
+    ):
+        json(payload, dumps=sdumps)
+
+    Sanic("...", dumps=sdumps)
+    with pytest.raises(
+        TypeError, match="Object of type Foo is not JSON serializable"
+    ):
+        json(payload)
+
+
+@pytest.mark.skipif(NO_UJSON is True, reason="ujson not installed")
+def test_json_response_json():
+    """One of the easiest ways to tell the difference is that ujson cannot
+    serialize over 64 bits"""
+    too_big_for_ujson = 111111111111111111111
+
+    with pytest.raises(OverflowError, match="int too big to convert"):
+        json(too_big_for_ujson)
+
+    response = json(too_big_for_ujson, dumps=sdumps)
+    assert sys.getsizeof(response.body) == 54
+
+    Sanic("...", dumps=sdumps)
+    response = json(too_big_for_ujson)
+    assert sys.getsizeof(response.body) == 54