Reintroduces tests for data normalizer

Author: palnabarun

mplaltair/tests/test_data.py

@@ -2,6 +2,10 @@
 import pandas as pd
 import mplaltair._data as _data
 import pytest
+from vega_datasets import data
+
+from mplaltair._data import _normalize_data
+from mplaltair._exceptions import ValidationError
 
 df = pd.DataFrame({
     "a": [1, 2, 3, 4, 5], "b": [1.1, 2.2, 3.3, 4.4, 5.5], "c": [1, 2.2, 3, 4.4, 5],
@@ -12,6 +16,36 @@
     "quantitative": [1.1, 2.1, 3.1, 4.1, 5.1]
 })
 
+def test_data_list():
+    spec = {
+        "data": {
+            "values": [{"a": 1, "b": 2}, {"c": 3, "d": 4}]
+
+        }
+    }
+    assert type(_normalize_data(spec)["data"]) == pd.DataFrame
+
+def test_data_url():
+    spec = {
+        "data": {
+            "url": data.cars.url
+        }
+    }
+    assert type(_normalize_data(spec)["data"]) == pd.DataFrame
+
+def test_data_no_pass():
+    spec = {}
+    with pytest.raises(ValidationError):
+        _normalize_data(spec)
+
+def test_data_invalid():
+    spec = {
+        "data": {
+            "source": "path"
+        }
+    }
+    with pytest.raises(NotImplementedError):
+        _normalize_data(spec)
 
 # _locate_channel_data() tests