evaluate all strings for newlines rather than pre-labeling attributes…

… likely to have them. natcap#49

src/geometamaker/models.py

@@ -264,7 +264,7 @@ def write(self, target_path):
 
         """
         with open(target_path, 'w') as file:
-            file.write(utils._yaml_dump(dataclasses.asdict(self)))
+            file.write(utils.yaml_dump(dataclasses.asdict(self)))
 
 
 @dataclass()
@@ -443,7 +443,7 @@ def set_lineage(self, statement):
                 provenance of the dataset
 
         """
-        self.lineage = utils.FoldedStr(f'{statement}')
+        self.lineage = statement
 
     def get_lineage(self):
         """Get the lineage statement of the dataset.
@@ -509,7 +509,7 @@ def write(self, workspace=None):
                 workspace, os.path.basename(self.metadata_path))
 
         with open(target_path, 'w') as file:
-            file.write(utils._yaml_dump(dataclasses.asdict(self)))
+            file.write(utils.yaml_dump(dataclasses.asdict(self)))
 
     def to_string(self):
         pass

src/geometamaker/utils.py

@@ -1,21 +1,16 @@
 import yaml
 
 
-class FoldedStr(str):
-    pass
+def represent_str(dumper, data):
+    scalar = yaml.representer.SafeRepresenter.represent_str(dumper, data)
+    if len(data.splitlines()) > 1:
+        scalar.style = '>'  # fold strings with newlines
+    return scalar
 
 
-def _change_style(style, representer):
-    def new_representer(dumper, data):
-        scalar = representer(dumper, data)
-        scalar.style = style
-        return scalar
-    return new_representer
-
-
-represent_folded_str = _change_style(
-    '>', yaml.representer.SafeRepresenter.represent_str)
-yaml.SafeDumper.add_representer(FoldedStr, represent_folded_str)
+# Patch the default string representer so that it uses
+# a folded style when the data contains newline characters
+yaml.SafeDumper.add_representer(str, represent_str)
 
 
 # https://stackoverflow.com/questions/13518819/avoid-references-in-pyyaml
@@ -26,7 +21,7 @@ def ignore_aliases(self, data):
         return True
 
 
-def _yaml_dump(data):
+def yaml_dump(data):
     return yaml.dump(
         data,
         allow_unicode=True,

tests/test_geometamaker.py

@@ -396,11 +396,28 @@ def test_set_and_get_lineage(self):
         import geometamaker
 
         resource = geometamaker.models.Resource()
-        statement = 'a lineage statment'
+        statement = 'a lineage statment\n is long and has\n many lines.'
 
         resource.set_lineage(statement)
         self.assertEqual(resource.get_lineage(), statement)
 
+    def test_lineage_roundtrip(self):
+        """Test writing and loading yaml with custom style."""
+        import geometamaker
+
+        datasource_path = os.path.join(self.workspace_dir, 'raster.tif')
+        numpy_type = numpy.int16
+        create_raster(numpy_type, datasource_path)
+
+        resource = geometamaker.describe(datasource_path)
+
+        statement = 'a lineage statment\n is long and has\n many lines.'
+        resource.set_lineage(statement)
+        resource.write()
+
+        new_resource = geometamaker.describe(datasource_path)
+        self.assertEqual(new_resource.get_lineage(), statement)
+
     def test_set_and_get_purpose(self):
         """Test set and get purpose of resource."""
         import geometamaker