Update Plot test, pyproject.toml and README.md (#27)

Author: b-yogesh

dashipy/tests/components/plot_test.py

@@ -1,7 +1,36 @@
+import json
 import unittest
 
+import pandas as pd
+import altair as alt
+
+from dashipy.components import Plot
+
 
 class PlotTest(unittest.TestCase):
+    def setUp(self):
+        dataset = pd.DataFrame(
+            {"x": ["A", "B", "C", "D", "E"], "a": [28, 55, 43, 91, 81]}
+        )
+        self.chart = (
+            alt.Chart(dataset)
+            .mark_bar()
+            .encode(
+                x=alt.X("x:N", title="x"),
+                y=alt.Y("a:Q", title="a"),
+            )
+        )
 
     def test_is_json_serializable(self):
-        pass
+
+        plot = Plot(id="plot", chart=self.chart)
+        p = plot.to_dict()
+
+        print(p)
+        self.assertIsInstance(p, dict)
+        self.assertEqual(p["type"], "Plot")
+        self.assertIsInstance(p["chart"], dict)
+        self.assertEqual(p["chart"]["mark"], {"type": "bar"})
+        json_text = json.dumps(p)
+        self.assertEqual("{", json_text[0])
+        self.assertEqual("}", json_text[-1])