refactoring: skipping invalid parameter combinations

test/fixtures/input.py

@@ -5,6 +5,7 @@ import pytest
 from PIL import Image
 from funcy import lmap, compose, flatten
 
+from pyinfra.server.dispatcher.dispatcher import Nothing
 from pyinfra.server.utils import pack, unpack, normalize_item
 from pyinfra.utils.func import star, lift, lstarlift
 from test.utils.image import image_to_bytes
@@ -32,6 +33,8 @@ def input_data_items(item_type, n_items, pdf):
 
 @pytest.fixture
 def targets(input_data_items, item_type, operation, metadata):
+    if operation is Nothing:
+        return Nothing
     op = compose(lift(star(pack)), normalize_item, operation)
     expected = lmap(unpack, flatten(starmap(op, zip(input_data_items, metadata))))
     return expected

test/fixtures/server.py

@@ -7,10 +7,11 @@ import fitz
 import pytest
 import requests
 from PIL import Image
-from funcy import retry, first, compose
+from funcy import retry, first, compose, identity
 from waitress import serve
 
 from pyinfra.server.bufferizer.lazy_bufferizer import FlatStreamBuffer
+from pyinfra.server.dispatcher.dispatcher import Nothing
 from pyinfra.server.server import (
     set_up_processing_server,
     make_streamable_and_wrap_in_packing_logic,
@@ -66,9 +67,15 @@ def operation(core_operation):
             return zip(result, metadata)
         else:
             return result, metadata
+    if core_operation is Nothing:
+        return Nothing
     return op
 
 
+class InvalidParameterCombination(ValueError):
+    pass
+
+
 @pytest.fixture
 def core_operation(item_type, one_to_many):
     def upper(string: bytes):
@@ -88,9 +95,19 @@ def core_operation(item_type, one_to_many):
             yield f"page_{i}".encode()
 
     try:
-        return {"string": duplicate if one_to_many else upper, "image": rotate, "pdf": stream_pages}[item_type]
+        d = {
+            False: {
+                "string": upper,
+                "image": rotate,
+            },
+            True: {
+                "string": duplicate,
+                "pdf": stream_pages,
+            },
+        }
+        return d[one_to_many][item_type]
     except KeyError:
-        raise ValueError(f"No operation specified for item type {item_type}")
+        return Nothing
 
 
 @pytest.fixture(params=["pdf", "string", "image"])

test/unit_tests/server/pipeline_test.py

@@ -2,6 +2,7 @@ import pytest
 from funcy import rcompose, lmap
 
 from pyinfra.server.client_pipeline import ClientPipeline
+from pyinfra.server.dispatcher.dispatcher import Nothing
 from pyinfra.server.dispatcher.dispatchers.forwarding import ForwardingDispatcher
 from pyinfra.server.dispatcher.dispatchers.rest import RestDispatcher
 from pyinfra.server.interpreter.interpreters.identity import IdentityInterpreter
@@ -11,6 +12,7 @@ from pyinfra.server.receiver.receivers.identity import IdentityReceiver
 from pyinfra.server.receiver.receivers.rest import RestReceiver
 from pyinfra.server.utils import unpack
 from pyinfra.utils.func import lift
+from test.fixtures.server import InvalidParameterCombination
 
 
 def test_mock_pipeline():
@@ -24,6 +26,17 @@ def test_mock_pipeline():
     assert list(pipeline(data)) == list(rcompose(f, g, h, u)(data))
 
 
+def pass_invalid_combination(fn):
+    def inner(*args, **kwargs):
+        try:
+            return fn(*args, **kwargs)
+        except InvalidParameterCombination:
+            pass
+
+    return inner
+
+
+# @pass_invalid_combination
 @pytest.mark.parametrize(
     "client_pipeline_type",
     [
@@ -31,7 +44,9 @@ def test_mock_pipeline():
         # "basic",
     ],
 )
-def test_pipeline(client_pipeline, input_data_items, metadata, targets):
+def test_pipeline(core_operation, client_pipeline, input_data_items, metadata, targets, item_type, one_to_many):
+    if targets is Nothing:
+        pytest.skip(f"invalid parameter combination: {item_type=}, {one_to_many=}")
     output = client_pipeline(input_data_items, metadata)
     output = lmap(unpack, output)
     assert output == targets
@@ -75,7 +90,9 @@ def rest_client_pipeline(server_process, endpoint, rest_interpreter):
 
 @pytest.fixture
 def basic_client_pipeline(endpoint, rest_interpreter, server_stream_function):
-    return ClientPipeline(RestPacker(), ForwardingDispatcher(server_stream_function), IdentityReceiver(), IdentityInterpreter())
+    return ClientPipeline(
+        RestPacker(), ForwardingDispatcher(server_stream_function), IdentityReceiver(), IdentityInterpreter()
+    )
 
 
 @pytest.fixture