TST: implement deserialization tests for older schema versions (#45048)

Author: José Duarte

pandas/tests/io/json/test_json_table_schema.py

@@ -789,3 +789,25 @@ def test_empty_frame_roundtrip(self):
         out = df.to_json(orient="table")
         result = pd.read_json(out, orient="table")
         tm.assert_frame_equal(expected, result)
+
+    def test_read_json_orient_table_old_schema_version(self):
+        df_json = """
+        {
+            "schema":{
+                "fields":[
+                    {"name":"index","type":"integer"},
+                    {"name":"a","type":"string"}
+                ],
+                "primaryKey":["index"],
+                "pandas_version":"0.20.0"
+            },
+            "data":[
+                {"index":0,"a":1},
+                {"index":1,"a":2.0},
+                {"index":2,"a":"s"}
+            ]
+        }
+        """
+        expected = DataFrame({"a": [1, 2.0, "s"]})
+        result = pd.read_json(df_json, orient="table")
+        tm.assert_frame_equal(expected, result)