address more comments

python/cudf/cudf/_lib/pylibcudf/io/types.pyx

@@ -200,6 +200,8 @@ cdef class SinkInfo:
         if isinstance(sinks[0], io.StringIO):
             data_sinks.reserve(len(sinks))
             for s in sinks:
+                if not isinstance(s, io.StringIO):
+                    raise ValueError("All sinks must be of the same type!")
                 self.sink_storage.push_back(
                     unique_ptr[data_sink](new iobase_data_sink(s))
                 )
@@ -219,8 +221,10 @@ cdef class SinkInfo:
                     }:
                         raise NotImplementedError(f"Unsupported encoding {s.encoding}")
                     sink = move(unique_ptr[data_sink](new iobase_data_sink(s.buffer)))
-                else:
+                elif isinstance(s, io.BytesIO):
                     sink = move(unique_ptr[data_sink](new iobase_data_sink(s)))
+                else:
+                    raise ValueError("All sinks must be of the same type!")
 
                 self.sink_storage.push_back(
                     move(sink)
@@ -230,7 +234,9 @@ cdef class SinkInfo:
         elif isinstance(sinks[0], (basestring, os.PathLike)):
             paths.reserve(len(sinks))
             for s in sinks:
+                if not isinstance(s, (basestring, os.PathLike)):
+                    raise ValueError("All sinks must be of the same type!")
                 paths.push_back(<string> os.path.expanduser(s).encode())
             self.c_obj = sink_info(move(paths))
         else:
-            raise TypeError("Unrecognized input type: {}".format(type(sinks)))
+            raise TypeError("Unrecognized input type: {}".format(type(sinks[0])))

python/cudf/cudf/pylibcudf_tests/test_source_info.py → python/cudf/cudf/pylibcudf_tests/io/test_source_sink_info.py

@@ -7,19 +7,24 @@
 import cudf._lib.pylibcudf as plc
 
 
+@pytest.fixture(params=[plc.io.SourceInfo, plc.io.SinkInfo])
+def io_class(request):
+    return request.param
+
+
 @pytest.mark.parametrize(
     "source", ["a.txt", b"hello world", io.BytesIO(b"hello world")]
 )
-def test_source_info_ctor(source, tmp_path):
+def test_source_info_ctor(io_class, source, tmp_path):
     if isinstance(source, str):
         file = tmp_path / source
         file.write_bytes("hello world".encode("utf-8"))
         source = str(file)
 
-    plc.io.SourceInfo([source])
+    if io_class is plc.io.SinkInfo and isinstance(source, bytes):
+        pytest.skip("bytes is not a valid input for SinkInfo")
 
-    # TODO: test contents of source_info buffer is correct
-    # once buffers are exposed on python side
+    io_class([source])
 
 
 @pytest.mark.parametrize(
@@ -30,18 +35,17 @@ def test_source_info_ctor(source, tmp_path):
         [io.BytesIO(b"hello world"), io.BytesIO(b"hello there")],
     ],
 )
-def test_source_info_ctor_multiple(sources, tmp_path):
+def test_source_info_ctor_multiple(io_class, sources, tmp_path):
     for i in range(len(sources)):
         source = sources[i]
         if isinstance(source, str):
             file = tmp_path / source
             file.write_bytes("hello world".encode("utf-8"))
             sources[i] = str(file)
+        elif io_class is plc.io.SinkInfo and isinstance(source, bytes):
+            pytest.skip("bytes is not a valid input for SinkInfo")
 
-    plc.io.SourceInfo(sources)
-
-    # TODO: test contents of source_info buffer is correct
-    # once buffers are exposed on python side
+    io_class(sources)
 
 
 @pytest.mark.parametrize(
@@ -56,7 +60,7 @@ def test_source_info_ctor_multiple(sources, tmp_path):
         ],
     ],
 )
-def test_source_info_ctor_mixing_invalid(sources, tmp_path):
+def test_source_info_ctor_mixing_invalid(io_class, sources, tmp_path):
     # Unlike the previous test
     # don't create files so that they are missing
     for i in range(len(sources)):
@@ -65,5 +69,7 @@ def test_source_info_ctor_mixing_invalid(sources, tmp_path):
             file = tmp_path / source
             file.write_bytes("hello world".encode("utf-8"))
             sources[i] = str(file)
+        elif io_class is plc.io.SinkInfo and isinstance(source, bytes):
+            pytest.skip("bytes is not a valid input for SinkInfo")
     with pytest.raises(ValueError):
-        plc.io.SourceInfo(sources)
+        io_class(sources)