Simplify roundtrip io tests (#1702)

tests/test_readwrite.py

@@ -3,6 +3,7 @@
 import re
 import warnings
 from contextlib import contextmanager
+from functools import partial
 from importlib.util import find_spec
 from pathlib import Path
 from string import ascii_letters
@@ -25,6 +26,7 @@
 
 if TYPE_CHECKING:
     from os import PathLike
+    from typing import Literal
 
 HERE = Path(__file__).parent
 
@@ -658,30 +660,13 @@ def random_cats(n):
     assert_equal(orig, curr)
 
 
-def test_write_string_types(tmp_path, diskfmt):
-    # https://github.com/scverse/anndata/issues/456
-    adata_pth = tmp_path / f"adata.{diskfmt}"
-
-    adata = ad.AnnData(
-        obs=pd.DataFrame(
-            np.ones((3, 2)),
-            columns=["a", np.str_("b")],
-            index=["a", "b", "c"],
-        ),
-    )
-
-    write = getattr(adata, f"write_{diskfmt}")
-    read = getattr(ad, f"read_{diskfmt}")
-
-    write(adata_pth)
-    from_disk = read(adata_pth)
-
-    assert_equal(adata, from_disk)
-
+def test_write_string_type_error(tmp_path, diskfmt):
+    adata = ad.AnnData(obs=dict(obs_names=list("abc")))
     adata.obs[b"c"] = np.zeros(3)
+
     # This should error, and tell you which key is at fault
     with pytest.raises(TypeError, match=r"writing key 'obs'") as exc_info:
-        write(adata_pth)
+        getattr(adata, f"write_{diskfmt}")(tmp_path / f"adata.{diskfmt}")
 
     assert "b'c'" in str(exc_info.value)
 
@@ -722,15 +707,39 @@ def test_zarr_chunk_X(tmp_path):
 # Round-tripping scanpy datasets
 ################################
 
-diskfmt2 = diskfmt
+
+def _do_roundtrip(
+    adata: ad.AnnData, pth: Path, diskfmt: Literal["h5ad", "zarr"]
+) -> ad.AnnData:
+    getattr(adata, f"write_{diskfmt}")(pth)
+    return getattr(ad, f"read_{diskfmt}")(pth)
+
+
+@pytest.fixture
+def roundtrip(diskfmt):
+    return partial(_do_roundtrip, diskfmt=diskfmt)
+
+
+def test_write_string_types(tmp_path, diskfmt, roundtrip):
+    # https://github.com/scverse/anndata/issues/456
+    adata_pth = tmp_path / f"adata.{diskfmt}"
+
+    adata = ad.AnnData(
+        obs=pd.DataFrame(
+            np.ones((3, 2)),
+            columns=["a", np.str_("b")],
+            index=["a", "b", "c"],
+        ),
+    )
+
+    from_disk = roundtrip(adata, adata_pth)
+
+    assert_equal(adata, from_disk)
 
 
 @pytest.mark.skipif(not find_spec("scanpy"), reason="Scanpy is not installed")
-def test_scanpy_pbmc68k(tmp_path, diskfmt, diskfmt2):
-    read1 = lambda pth: getattr(ad, f"read_{diskfmt}")(pth)
-    write1 = lambda adata, pth: getattr(adata, f"write_{diskfmt}")(pth)
-    read2 = lambda pth: getattr(ad, f"read_{diskfmt2}")(pth)
-    write2 = lambda adata, pth: getattr(adata, f"write_{diskfmt2}")(pth)
+def test_scanpy_pbmc68k(tmp_path, diskfmt, roundtrip, diskfmt2):
+    roundtrip2 = partial(_do_roundtrip, diskfmt=diskfmt2)
 
     filepth1 = tmp_path / f"test1.{diskfmt}"
     filepth2 = tmp_path / f"test2.{diskfmt2}"
@@ -745,17 +754,15 @@ def test_scanpy_pbmc68k(tmp_path, diskfmt, diskfmt2):
         warnings.simplefilter("ignore", ad.OldFormatWarning)
         pbmc = sc.datasets.pbmc68k_reduced()
 
-    write1(pbmc, filepth1)
-    from_disk1 = read1(filepth1)  # Do we read okay
-    write2(from_disk1, filepth2)  # Can we round trip
-    from_disk2 = read2(filepth2)
+    from_disk1 = roundtrip(pbmc, filepth1)  # Do we read okay
+    from_disk2 = roundtrip2(from_disk1, filepth2)  # Can we round trip
 
     assert_equal(pbmc, from_disk1)  # Not expected to be exact due to `nan`s
     assert_equal(pbmc, from_disk2)
 
 
 @pytest.mark.skipif(not find_spec("scanpy"), reason="Scanpy is not installed")
-def test_scanpy_krumsiek11(tmp_path, diskfmt):
+def test_scanpy_krumsiek11(tmp_path, diskfmt, roundtrip):
     filepth = tmp_path / f"test.{diskfmt}"
     with warnings.catch_warnings():
         warnings.filterwarnings(
@@ -769,11 +776,10 @@ def test_scanpy_krumsiek11(tmp_path, diskfmt):
     del orig.uns["highlights"]  # Can’t write int keys
     # Can’t write "string" dtype: https://github.com/scverse/anndata/issues/679
     orig.obs["cell_type"] = orig.obs["cell_type"].astype(str)
-    getattr(orig, f"write_{diskfmt}")(filepth)
     with pytest.warns(UserWarning, match=r"Observation names are not unique"):
-        read = getattr(ad, f"read_{diskfmt}")(filepth)
+        curr = roundtrip(orig, filepth)
 
-    assert_equal(orig, read, exact=True)
+    assert_equal(orig, curr, exact=True)
 
 
 # Checking if we can read legacy zarr files
@@ -808,11 +814,8 @@ def test_backwards_compat_zarr():
     assert_equal(pbmc_zarr, pbmc_orig)
 
 
-# TODO: use diskfmt fixture once zarr backend implemented
-def test_adata_in_uns(tmp_path, diskfmt):
+def test_adata_in_uns(tmp_path, diskfmt, roundtrip):
     pth = tmp_path / f"adatas_in_uns.{diskfmt}"
-    read = lambda pth: getattr(ad, f"read_{diskfmt}")(pth)
-    write = lambda adata, pth: getattr(adata, f"write_{diskfmt}")(pth)
 
     orig = gen_adata((4, 5))
     orig.uns["adatas"] = {
@@ -823,20 +826,16 @@ def test_adata_in_uns(tmp_path, diskfmt):
     another_one.raw = gen_adata((2, 7))
     orig.uns["adatas"]["b"].uns["another_one"] = another_one
 
-    write(orig, pth)
-    curr = read(pth)
+    curr = roundtrip(orig, pth)
 
     assert_equal(orig, curr)
 
 
-def test_io_dtype(tmp_path, diskfmt, dtype):
+def test_io_dtype(tmp_path, diskfmt, dtype, roundtrip):
     pth = tmp_path / f"adata_dtype.{diskfmt}"
-    read = lambda pth: getattr(ad, f"read_{diskfmt}")(pth)
-    write = lambda adata, pth: getattr(adata, f"write_{diskfmt}")(pth)
 
     orig = ad.AnnData(np.ones((5, 8), dtype=dtype))
-    write(orig, pth)
-    curr = read(pth)
+    curr = roundtrip(orig, pth)
 
     assert curr.X.dtype == dtype