Add user-generated annotations tests to the server (#1164)

* Add user-generated annotations tests to the server

Partially completes https://github.com/chanzuckerberg/cellxgene/issues/969

* Auto-format python code

* @skip_if: passing lambdas > than property strings

* Respond to feedback from @bkmartinjr

server/test/__init__.py

@@ -0,0 +1,50 @@
+import shutil
+import tempfile
+from os import path
+
+import pandas as pd
+
+from server.common.annotations import AnnotationsLocalFile
+from server.common.data_locator import DataLocator
+from server.data_common.fbs.matrix import encode_matrix_fbs
+from server.data_common.matrix_loader import MatrixDataLoader, MatrixDataType
+
+
+def data_with_tmp_annotations(ext: MatrixDataType, annotations_fixture=False):
+    tmp_dir = tempfile.mkdtemp()
+    annotations_file = path.join(tmp_dir, "test_annotations.csv")
+    if annotations_fixture:
+        shutil.copyfile(f"test/test_datasets/pbmc3k-annotations.csv", annotations_file)
+    args = {
+        "layout": ["umap"],
+        "max_category_items": 100,
+        "obs_names": None,
+        "var_names": None,
+        "diffexp_lfc_cutoff": 0.01,
+    }
+    fname = {
+        MatrixDataType.H5AD: "../example-dataset/pbmc3k.h5ad",
+        MatrixDataType.CXG: "test/test_datasets/pbmc3k.cxg",
+    }[ext]
+    data_locator = DataLocator(fname)
+    data = MatrixDataLoader(data_locator.abspath()).open(args)
+    annotations = AnnotationsLocalFile(None, annotations_file)
+    return data, tmp_dir, annotations
+
+
+def make_fbs(data):
+    df = pd.DataFrame(data)
+    return encode_matrix_fbs(matrix=df, row_idx=None, col_idx=df.columns)
+
+
+def skip_if(condition, reason: str):
+    def decorator(f):
+        def wraps(self, *args, **kwargs):
+            if condition(self):
+                self.skipTest(reason)
+            else:
+                f(self, *args, **kwargs)
+
+        return wraps
+
+    return decorator