add plaintext ofmt to patch tool

nested_diff/cli.py

@@ -35,7 +35,7 @@ class App:
         'toml',
         'yaml',
     )
-    supported_ofmts = ('auto', 'ini', 'json', 'toml', 'yaml')
+    supported_ofmts = supported_ifmts
 
     version = nested_diff.__version__
 
@@ -154,6 +154,8 @@ def get_dumper(fmt, **kwargs):
             return IniDumper(**kwargs)
         if fmt == 'toml':
             return TomlDumper(**kwargs)
+        if fmt == 'plaintext':
+            return Dumper(**kwargs)
 
         raise RuntimeError(f'Unsupported output format: {fmt}')
 
@@ -271,7 +273,7 @@ def encode(self, data):
             NotImplementedError: Must be implemented in derivatives.
 
         """
-        raise NotImplementedError
+        return data
 
     @staticmethod
     def get_opts(opts):

tests/cli/shared.txt.patch.json

@@ -0,0 +1,25 @@
+{
+   "D": [
+      {
+         "I": [
+            0,
+            4,
+            0,
+            3
+         ]
+      },
+      {
+         "U": "one"
+      },
+      {
+         "U": "two"
+      },
+      {
+         "R": "three"
+      },
+      {
+         "U": ""
+      }
+   ],
+   "E": 5
+}

tests/cli/test_cli.py

@@ -9,12 +9,11 @@ def encode(self, data):
         return data
 
 
-def test_abstract_dumper_encode():
-    with pytest.raises(NotImplementedError):
-        cli.Dumper().encode('data')
+def test_base_dumper_encode():
+    assert cli.Dumper().encode('data') == 'data'
 
 
-def test_abstract_loader_decode():
+def test_base_loader_decode():
     assert cli.Loader().decode('data') == 'data'
 
 

tests/cli/test_patch_tool.py

@@ -172,6 +172,30 @@ def test_toml_fmt(capsys, content, rpath, tmp_path):
     assert content(result_file_name) == expected
 
 
+def test_plaintext_fmt(capsys, content, rpath, tmp_path):
+    result_file_name = f'{tmp_path}.got.txt'
+    copyfile(
+        rpath('shared.a.txt'),
+        result_file_name,
+    )
+    exit_code = nested_diff.patch_tool.App(
+        args=(
+            '--ofmt',
+            'plaintext',
+            result_file_name,
+            rpath('shared.txt.patch.json'),
+        ),
+    ).run()
+
+    captured = capsys.readouterr()
+    assert captured.out == ''
+    assert captured.err == ''
+    assert exit_code == 0
+
+    expected = content(rpath('shared.b.txt'))
+    assert content(result_file_name) == expected
+
+
 def test_entry_point(capsys):
     with mock.patch('sys.argv', ['nested_patch', '-h']):
         with pytest.raises(SystemExit) as e: