diff --git a/adr/formatter.py b/adr/formatter.py
index 850b5e1..1fe320b 100644
--- a/adr/formatter.py
+++ b/adr/formatter.py
@@ -21,6 +21,7 @@ def __init__(self, table_cls=SingleTable):
         self.table_cls = table_cls
 
     def __call__(self, data):
+        print(data)
         if isinstance(data, bytes):
             data = json.loads(data)
 
diff --git a/test/formatter_tests/__init__.py b/test/formatter_tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/test/formatter_tests/jsonformatter_expected.json b/test/formatter_tests/jsonformatter_expected.json
new file mode 100644
index 0000000..c5e6c4e
--- /dev/null
+++ b/test/formatter_tests/jsonformatter_expected.json
@@ -0,0 +1 @@
+{"expected_json": ["[\n  [\n    \"Heading A\",\n    \"Heading B\"\n  ],\n  [\n    1,\n    2\n  ],\n  [\n    3,\n    4\n  ],\n  [\n    5,\n    6\n  ]\n]", "{\n  \"names\": [\n    \"Heading A\",\n    \"Heading B\",\n    \"Heading C\"\n  ],\n  \"Heading A\": [\n    \"x\",\n    \"y\"\n  ],\n  \"Heading B\": [\n    11,\n    20.5\n  ],\n  \"Heading C\": [\n    12,\n    30.5\n  ]\n}"]}
\ No newline at end of file
diff --git a/test/formatter_tests/markdownformatter_expected.json b/test/formatter_tests/markdownformatter_expected.json
new file mode 100644
index 0000000..57f1fdc
--- /dev/null
+++ b/test/formatter_tests/markdownformatter_expected.json
@@ -0,0 +1 @@
+{"expected_markdown": ["\n| Heading A | Heading B |\n|-----------|-----------|\n| 1         | 2         |\n| 3         | 4         |\n| 5         | 6         |\n", "\n| Heading A | Heading B | Heading C |\n|-----------|-----------|-----------|\n| x         | 11        | 12        |\n| y         | 20.5      | 30.5      |"]}
\ No newline at end of file
diff --git a/test/formatter_tests/tableformatter_expected.json b/test/formatter_tests/tableformatter_expected.json
new file mode 100644
index 0000000..1247d14
--- /dev/null
+++ b/test/formatter_tests/tableformatter_expected.json
@@ -0,0 +1 @@
+{"expected_table": ["\n┌───────────┬───────────┐\n│ Heading A │ Heading B │\n├───────────┼───────────┤\n│ 1         │ 2         │\n│ 3         │ 4         │\n│ 5         │ 6         │\n└───────────┴───────────┘", "\n┌───────────┬───────────┬───────────┐\n│ Heading A │ Heading B │ Heading C │\n├───────────┼───────────┼───────────┤\n│ x         │ 11        │ 12        │\n│ y         │ 20.5      │ 30.5      │\n└───────────┴───────────┴───────────┘"]}
\ No newline at end of file
diff --git a/test/test_formatter.py b/test/test_formatter.py
new file mode 100644
index 0000000..de628d1
--- /dev/null
+++ b/test/test_formatter.py
@@ -0,0 +1,43 @@
+import os
+import io
+import json
+import pytest
+import formatter_tests
+from adr.formatter import all_formatters
+
+
+test_data=([['Heading A', 'Heading B'],[1, 2],[3, 4],[5,6]],{'names': ['Heading A', 'Heading B', 'Heading C'],
+    'Heading A': ['x', 'y'],
+    'Heading B': [11, 20.5],
+    'Heading C': [12, 30.5]
+})
+
+def get_data(path):
+    with io.open(path,'r',encoding="utf-8") as f:
+        data = json.load(f)
+    return data
+
+
+test_dir=os.path.dirname(formatter_tests.__file__)
+
+expected_table=get_data(os.path.join(test_dir,'tableformatter_expected.json'))["expected_table"]
+expected_json= get_data(os.path.join(test_dir,'jsonformatter_expected.json'))["expected_json"]
+expected_markdown=get_data(os.path.join(test_dir,'markdownformatter_expected.json'))["expected_markdown"]
+
+
+
+@pytest.mark.parametrize("test_data,expected_json",list(zip(test_data,expected_json)),ids=["jsonformat_case1", "jsonformat_case2"])
+def test_jsonformatter(test_data,expected_json):
+    """check MarkdownFormatter method """
+    assert all_formatters['json'](test_data)==expected_json.strip()
+
+
+@pytest.mark.parametrize("test_data,expected_table",list(zip(test_data,expected_table)),ids=["tableformat_case1", "tableformat_case2"])
+def test_tableformatter(test_data,expected_table):
+    """check MarkdownFormatter method """
+    assert all_formatters['table'](test_data)==expected_table.strip()
+
+@pytest.mark.parametrize("test_data,expected_markdown",list(zip(test_data,expected_markdown)),ids=["markdownformat1", "markdownformat2"])
+def test_markdownformatter(test_data,expected_markdown):
+    """check MarkdownFormatter method """
+    assert all_formatters['markdown'](test_data)==expected_markdown.strip()