Create SearchMetadata for classes that used to inherit from Metadata

docs/reference/components.rst

@@ -95,7 +95,7 @@ Item metadata components
 
 .. autoclass:: zyte_common_items.Metadata(**kwargs)
    :show-inheritance:
-   :members: dateDownloaded, probability, searchText, validationMessages
+   :members: dateDownloaded, displayedQuery, probability, searchedQuery, searchText, totalOrganicResults, validationMessages, get_date_downloaded_parsed
 
 .. autoclass:: zyte_common_items.ProbabilityMetadata(**kwargs)
    :show-inheritance:
@@ -109,6 +109,10 @@ Item metadata components
    :show-inheritance:
    :members: probability, dateDownloaded, validationMessages, get_date_downloaded_parsed
 
+.. autoclass:: zyte_common_items.SearchMetadata(**kwargs)
+   :show-inheritance:
+   :members: dateDownloaded, probability, searchText, validationMessages, get_date_downloaded_parsed
+
 .. autoclass:: zyte_common_items.BaseMetadata(**kwargs)
    :show-inheritance:
    :members: cast

tests/test_components.py

@@ -93,6 +93,12 @@ def test_metadata_fields():
         ), f"Metadata is missing some fields from {cls.__name__}: {subset - superset}"
 
 
+def test_metadata_subclasses():
+    """Metadata should not be subclassed, since its fields will grow as new
+    specific metadata classes are added."""
+    assert not get_all_subclasses(Metadata)
+
+
 def test_named_link_optional_fields():
     NamedLink(name="foo")
     NamedLink(url="https://example.com")

zyte_common_items/__init__.py

@@ -29,6 +29,7 @@
     Reactions,
     RealEstateArea,
     Request,
+    SearchMetadata,
     SocialMediaPostAuthor,
     StarRating,
     Topic,

zyte_common_items/components/__init__.py

@@ -18,6 +18,7 @@
     Metadata,
     MetadataT,
     ProbabilityMetadata,
+    SearchMetadata,
 )
 from .ratings import AggregateRating, StarRating
 from .real_estate import RealEstateArea

zyte_common_items/components/metadata.py

@@ -74,7 +74,16 @@ class DetailsMetadata(ListMetadata):
 
 
 @attrs.define(kw_only=True)
-class Metadata(DetailsMetadata):
+class SearchMetadata(DetailsMetadata):
+    """Minimal metadata for classes of items that can declare search
+    metadata."""
+
+    #: The search text used to find the item.
+    searchText: Optional[str] = None
+
+
+@attrs.define(kw_only=True)
+class Metadata(SearchMetadata):
     """Generic metadata class.
 
     It defines all attributes of metadata classes for specific item types, so
@@ -88,8 +97,5 @@ class Metadata(DetailsMetadata):
     #: Search query as specified in the input URL.
     searchedQuery: Optional[str] = None
 
-    #: The search text used to find the item.
-    searchText: Optional[str] = None
-
     #: Total number of organic results reported by the search engine.
     totalOrganicResults: Optional[int] = None

zyte_common_items/items/business_place.py

@@ -9,17 +9,17 @@
     AggregateRating,
     Amenity,
     Image,
-    Metadata,
     NamedLink,
     OpeningHoursItem,
     ParentPlace,
+    SearchMetadata,
     StarRating,
 )
 from zyte_common_items.converters import to_metadata_optional, url_to_str_optional
 
 
 @attrs.define(kw_only=True)
-class BusinessPlaceMetadata(Metadata):
+class BusinessPlaceMetadata(SearchMetadata):
     """Metadata class for :data:`zyte_common_items.BusinessPlace.metadata`."""
 
 

zyte_common_items/items/job_posting.py

@@ -7,13 +7,13 @@
     BaseSalary,
     HiringOrganization,
     JobLocation,
-    Metadata,
+    SearchMetadata,
 )
 from zyte_common_items.converters import to_metadata_optional, url_to_str
 
 
 @attrs.define(kw_only=True)
-class JobPostingMetadata(Metadata):
+class JobPostingMetadata(SearchMetadata):
     """Metadata class for :data:`zyte_common_items.JobPosting.metadata`."""
 
 

zyte_common_items/items/social_media_post.py

@@ -3,12 +3,17 @@
 import attrs
 
 from zyte_common_items.base import Item
-from zyte_common_items.components import Metadata, Reactions, SocialMediaPostAuthor, Url
+from zyte_common_items.components import (
+    Reactions,
+    SearchMetadata,
+    SocialMediaPostAuthor,
+    Url,
+)
 from zyte_common_items.converters import to_metadata_optional, url_to_str
 
 
 @attrs.define(kw_only=True)
-class SocialMediaPostMetadata(Metadata):
+class SocialMediaPostMetadata(SearchMetadata):
     """Metadata class for :data:`zyte_common_items.SocialMediaPost.metadata`."""