Merge pull request #127 from jacebrowning/enable-old-serialization

Add an option to use unindented YAML blocks

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 0.5 (unreleased)
+
+- Added an `INDENT_YAML_BLOCKS` setting to optionally use the old serialization behavior.
+
 # 0.4.1 (2019-08-25)
 
 - Fixed a `TypeError` when converting non-builtin attributes.

datafiles/__init__.py

@@ -2,7 +2,7 @@
 
 from dataclasses import field
 
-from . import converters
+from . import converters, settings
 from .decorators import auto, datafile
 from .manager import Missing
 from .model import Model

datafiles/formats.py

@@ -8,6 +8,8 @@
 import tomlkit
 from ruamel import yaml
 
+from . import settings
+
 
 class Formatter(metaclass=ABCMeta):
     """Base class for object serialization and text deserialization."""
@@ -77,11 +79,14 @@ def deserialize(cls, file_object):
 
     @classmethod
     def serialize(cls, data):
-        f = StringIO()
-        y = yaml.YAML()
-        y.indent(mapping=2, sequence=4, offset=2)
-        y.dump(data, f)
-        text = f.getvalue().strip() + '\n'
+        if settings.INDENT_YAML_BLOCKS:
+            f = StringIO()
+            y = yaml.YAML()
+            y.indent(mapping=2, sequence=4, offset=2)
+            y.dump(data, f)
+            text = f.getvalue().strip() + '\n'
+        else:
+            text = yaml.round_trip_dump(data) or ""
         return "" if text == "{}\n" else text
 
 

datafiles/settings.py

@@ -1,5 +1,5 @@
 """Shared configuration flags."""
 
-HOOKS_ENABLED = True
-
 HIDE_TRACEBACK_IN_HOOKS = True
+HOOKS_ENABLED = True
+INDENT_YAML_BLOCKS = True

datafiles/tests/test_formats.py

@@ -2,7 +2,38 @@
 
 import pytest
 
-from datafiles import formats
+from datafiles import formats, settings
+from datafiles.utils import dedent
+
+
+def describe_serialize():
+    @pytest.fixture
+    def data():
+        return {'key': "value", 'items': [1, 2]}
+
+    def describe_yaml():
+        def it_indents_blocks_by_default(expect, data):
+            text = formats.YAML.serialize(data)
+            expect(text) == dedent(
+                """
+            key: value
+            items:
+              - 1
+              - 2
+            """
+            )
+
+        def it_can_render_lists_inline(expect, data, monkeypatch):
+            monkeypatch.setattr(settings, 'INDENT_YAML_BLOCKS', False)
+            text = formats.YAML.serialize(data)
+            expect(text) == dedent(
+                """
+            key: value
+            items:
+            - 1
+            - 2
+            """
+            )
 
 
 def describe_deserialize():

docs/settings.md

@@ -0,0 +1,54 @@
+<h1>Settings</h1>
+
+For libraries that wish to temporarly alter any of the previosly described behavior, a handful of settings can be set at the module level. All boolean settings default to `True` unless otherwise noted.
+
+# `HIDE_TRACEBACK_IN_HOOKS`
+
+When an exception occurs in patched method, this traceback is hidden by default for `pytest`. If this information is required to debug a complex issue enable it as follows:
+
+```python
+import datafiles
+
+datafiles.settings.HIDE_TRACEBACK_IN_HOOKS = False
+```
+
+# `HOOKS_ENABLED`
+
+When running unit tests for a library using `datafiles`,
+it can be helpful to disable automatic loading/saving in patched methods for performance:
+
+```python
+def pytest_runtest_setup(item):
+    """Disable file storage during unit tests."""
+    datafiles.settings.HOOKS_ENABLED = False
+```
+
+
+
+# `INDENT_YAML_BLOCKS`
+
+In `datafiles >= 0.4`, YAML blocks are now indented by default, like so:
+
+```yaml
+items:
+  - 1
+  - 2
+  - 3
+```
+
+To make it easier to upgrade to this version, a library can disable this functionality:
+
+```python
+import datafiles
+
+datafiles.settings.INDENT_YAML_BLOCKS = False
+```
+
+to produce YAML like:
+
+```yaml
+items:
+- 1
+- 2
+- 3
+```

mkdocs.yml

@@ -24,6 +24,7 @@ nav:
   - Custom Types: types/custom.md
 - File Formats: formats.md
 - Utilities: utilities.md
+- Settings: settings.md
 - About:
   - Release Notes: about/changelog.md
   - Contributing: about/contributing.md

pyproject.toml

@@ -1,7 +1,7 @@
 [tool.poetry]
 
 name = "datafiles"
-version = "0.4.1"
+version = "0.5b1"
 description = "File-based ORM for dataclasses."
 
 license = "MIT"