test(client): cover default-decoder resolution matrix for both clients

Author: lesnik512

tests/test_client_decoders_default.py

@@ -0,0 +1,102 @@
+"""Default decoder resolution under varying extras-installed states.
+
+Covers the behavior matrix in planning/specs/2026-06-09-multi-decoder-design.md
+— `AsyncClient()` / `Client()` resolve `decoders=None` against the
+`import_checker` flags at __init__ time.
+"""
+
+from unittest.mock import patch
+
+from httpware import AsyncClient, Client
+from httpware.decoders.msgspec import MsgspecDecoder
+from httpware.decoders.pydantic import PydanticDecoder
+
+
+def test_async_default_both_extras_installed() -> None:
+    client = AsyncClient()
+    types = tuple(type(d) for d in client._decoders)  # noqa: SLF001
+    assert types == (PydanticDecoder, MsgspecDecoder)
+
+
+def test_async_default_pydantic_only() -> None:
+    with patch("httpware._internal.import_checker.is_msgspec_installed", False):
+        client = AsyncClient()
+    types = tuple(type(d) for d in client._decoders)  # noqa: SLF001
+    assert types == (PydanticDecoder,)
+
+
+def test_async_default_msgspec_only() -> None:
+    with patch("httpware._internal.import_checker.is_pydantic_installed", False):
+        client = AsyncClient()
+    types = tuple(type(d) for d in client._decoders)  # noqa: SLF001
+    assert types == (MsgspecDecoder,)
+
+
+def test_async_default_neither_installed() -> None:
+    with (
+        patch("httpware._internal.import_checker.is_pydantic_installed", False),
+        patch("httpware._internal.import_checker.is_msgspec_installed", False),
+    ):
+        client = AsyncClient()
+    assert client._decoders == ()  # noqa: SLF001
+
+
+def test_async_empty_explicit_decoders() -> None:
+    client = AsyncClient(decoders=[])
+    assert client._decoders == ()  # noqa: SLF001
+
+
+def test_async_explicit_decoders_skip_default_probe() -> None:
+    class _Custom:
+        def can_decode(self, model: type) -> bool:  # noqa: ARG002  # pragma: no cover
+            return True
+
+        def decode(self, content: bytes, model: type) -> object:  # noqa: ARG002  # pragma: no cover
+            return None
+
+    custom = _Custom()
+    with (
+        patch("httpware._internal.import_checker.is_pydantic_installed", False),
+        patch("httpware._internal.import_checker.is_msgspec_installed", False),
+    ):
+        client = AsyncClient(decoders=[custom])
+    assert client._decoders == (custom,)  # noqa: SLF001
+
+
+def test_sync_default_both_extras_installed() -> None:
+    client = Client()
+    types = tuple(type(d) for d in client._decoders)  # noqa: SLF001
+    assert types == (PydanticDecoder, MsgspecDecoder)
+    client.close()
+
+
+def test_sync_default_pydantic_only() -> None:
+    with patch("httpware._internal.import_checker.is_msgspec_installed", False):
+        client = Client()
+    types = tuple(type(d) for d in client._decoders)  # noqa: SLF001
+    assert types == (PydanticDecoder,)
+    client.close()
+
+
+def test_sync_default_msgspec_only() -> None:
+    with patch("httpware._internal.import_checker.is_pydantic_installed", False):
+        client = Client()
+    types = tuple(type(d) for d in client._decoders)  # noqa: SLF001
+    assert types == (MsgspecDecoder,)
+    client.close()
+
+
+def test_sync_default_neither_installed() -> None:
+    with (
+        patch("httpware._internal.import_checker.is_pydantic_installed", False),
+        patch("httpware._internal.import_checker.is_msgspec_installed", False),
+    ):
+        client = Client()
+    assert client._decoders == ()  # noqa: SLF001
+    client.close()
+
+
+def test_sync_empty_explicit_decoders() -> None:
+    client = Client(decoders=[])
+    assert client._decoders == ()  # noqa: SLF001
+    client.close()