metadata: remove STRING/INT conversion on output

The type conversion should all happen in post_parse_yaml_metadata whenever
possible.  Also, when `if` blocks end in `return`, it is clearer if no
`elif` or `else` is used.

fdroidserver/metadata.py

@@ -1070,6 +1070,20 @@ def post_parse_yaml_metadata(yamldata):
         }
 
 
+def _format_multiline(value):
+    """TYPE_MULTILINE with newlines in them are saved as YAML literal strings."""
+    if '\n' in value:
+        return ruamel.yaml.scalarstring.preserve_literal(str(value))
+    return str(value)
+
+
+def _format_script(value):
+    """TYPE_SCRIPT with one value are converted to YAML string values."""
+    if len(value) == 1:
+        return value[0]
+    return value
+
+
 def _format_stringmap(appid, field, stringmap, versionCode=None):
     """Format TYPE_STRINGMAP taking into account localized files in the metadata dir.
 
@@ -1142,27 +1156,6 @@ def _del_duplicated_NoSourceSince(app):
             del app['AntiFeatures'][key]
 
 
-def _field_to_yaml(typ, value):
-    """Convert data to YAML 1.2 format that keeps the right TYPE_*."""
-    if typ == TYPE_STRING:
-        return str(value)
-    elif typ == TYPE_INT:
-        return int(value)
-    elif typ == TYPE_MULTILINE:
-        if '\n' in value:
-            return ruamel.yaml.scalarstring.preserve_literal(str(value))
-        else:
-            return str(value)
-    elif typ == TYPE_SCRIPT:
-        if type(value) == list:
-            if len(value) == 1:
-                return value[0]
-            else:
-                return value
-    else:
-        return value
-
-
 def _builds_to_yaml(app):
     builds = ruamel.yaml.comments.CommentedSeq()
     for build in app.get('Builds', []):
@@ -1179,7 +1172,7 @@ def _builds_to_yaml(app):
                     if v:
                         b[field] = v
                 elif value is not None and (typ == TYPE_INT or value):
-                    b.update({field: _field_to_yaml(typ, value)})
+                    b[field] = value
 
         builds.append(b)
 
@@ -1201,13 +1194,12 @@ def _app_to_yaml(app):
         else:
             value = app.get(field)
             if value or field == 'Builds':
+                _fieldtype = fieldtype(field)
                 if field == 'Builds':
                     if app.get('Builds'):
                         cm.update({field: _builds_to_yaml(app)})
                 elif field == 'Categories':
                     cm[field] = sorted(value, key=str.lower)
-                elif field == 'CurrentVersionCode':
-                    cm[field] = _field_to_yaml(TYPE_INT, value)
                 elif field == 'AntiFeatures':
                     v = _format_stringmap(app['id'], field, value)
                     if v:
@@ -1215,11 +1207,20 @@ def _app_to_yaml(app):
                 elif field == 'AllowedAPKSigningKeys':
                     value = [str(i).lower() for i in value]
                     if len(value) == 1:
-                        cm[field] = _field_to_yaml(TYPE_STRING, value[0])
+                        cm[field] = value[0]
                     else:
-                        cm[field] = _field_to_yaml(TYPE_LIST, value)
+                        cm[field] = value
+                elif _fieldtype == TYPE_MULTILINE:
+                    v = _format_multiline(value)
+                    if v:
+                        cm[field] = v
+                elif _fieldtype == TYPE_SCRIPT:
+                    v = _format_script(value)
+                    if v:
+                        cm[field] = v
                 else:
-                    cm[field] = _field_to_yaml(fieldtype(field), value)
+                    if value:
+                        cm[field] = value
 
                 if insert_newline:
                     # we need to prepend a newline in front of this field

tests/metadata.TestCase

@@ -1920,6 +1920,35 @@ class MetadataTest(unittest.TestCase):
         cm = metadata._app_to_yaml(metadata.App({'CurrentVersionCode': 0}))
         self.assertFalse('CurrentVersionCode' in cm)
 
+    def test_format_multiline(self):
+        self.assertEqual(metadata._format_multiline('description'), 'description')
+
+    def test_format_multiline_empty(self):
+        self.assertEqual(metadata._format_multiline(''), '')
+
+    def test_format_multiline_newline_char(self):
+        self.assertEqual(metadata._format_multiline('one\\ntwo'), 'one\\ntwo')
+
+    def test_format_multiline_newlines(self):
+        self.assertEqual(
+            metadata._format_multiline(
+                textwrap.dedent(
+                    """
+                    one
+                    two
+                    three
+                    """
+                )
+            ),
+            '\none\ntwo\nthree\n',
+        )
+
+    def test_format_script_newline(self):
+        self.assertEqual(metadata._format_script(['one\ntwo']), 'one\ntwo')
+
+    def test_format_script_newline_char(self):
+        self.assertEqual(metadata._format_script(['one\\ntwo']), 'one\\ntwo')
+
     def test_format_stringmap_empty(self):
         self.assertEqual(
             metadata._format_stringmap('🔥', 'test', dict()),