Fix: Update parser contract to require empty strings, not None (#12775)

Co-authored-by: stumpylog <797416+stumpylog@users.noreply.github.com>

src/paperless/parsers/__init__.py

@@ -281,13 +281,13 @@ class ParserProtocol(Protocol):
     # Result accessors
     # ------------------------------------------------------------------
 
-    def get_text(self) -> str | None:
+    def get_text(self) -> str:
         """Return the plain-text content extracted during parse.
 
         Returns
         -------
-        str | None
-            Extracted text, or None if no text could be found.
+        str
+            Extracted text, or an empty string if no text could be found.
         """
         ...
 

src/paperless/parsers/mail.py

@@ -285,15 +285,15 @@ class MailDocumentParser:
     # Result accessors
     # ------------------------------------------------------------------
 
-    def get_text(self) -> str | None:
+    def get_text(self) -> str:
         """Return the plain-text content extracted during parse.
 
         Returns
         -------
-        str | None
-            Extracted text, or None if parse has not been called yet.
+        str
+            Extracted text, or an empty string if no text could be found.
         """
-        return self._text
+        return self._text or ""
 
     def get_date(self) -> datetime.datetime | None:
         """Return the document date detected during parse.

src/paperless/parsers/remote.py

@@ -247,9 +247,9 @@ class RemoteDocumentParser:
     # Result accessors
     # ------------------------------------------------------------------
 
-    def get_text(self) -> str | None:
+    def get_text(self) -> str:
         """Return the plain-text content extracted during parse."""
-        return self._text
+        return self._text or ""
 
     def get_date(self) -> datetime.datetime | None:
         """Return the document date detected during parse.

src/paperless/parsers/tesseract.py

@@ -144,8 +144,8 @@ class RasterisedDocumentParser:
     # Result accessors
     # ------------------------------------------------------------------
 
-    def get_text(self) -> str | None:
-        return self.text
+    def get_text(self) -> str:
+        return self.text or ""
 
     def get_date(self) -> datetime.datetime | None:
         return self.date

src/paperless/parsers/text.py

@@ -189,15 +189,15 @@ class TextDocumentParser:
     # Result accessors
     # ------------------------------------------------------------------
 
-    def get_text(self) -> str | None:
+    def get_text(self) -> str:
         """Return the plain-text content extracted during parse.
 
         Returns
         -------
-        str | None
-            Extracted text, or None if parse has not been called yet.
+        str
+            Extracted text, or an empty string if no text could be found.
         """
-        return self._text
+        return self._text or ""
 
     def get_date(self) -> datetime.datetime | None:
         """Return the document date detected during parse.

src/paperless/parsers/tika.py

@@ -265,9 +265,7 @@ class TikaDocumentParser:
                 f"{settings.TIKA_ENDPOINT}: {err}",
             ) from err
 
-        self._text = parsed.content
-        if self._text is not None:
-            self._text = self._text.strip()
+        self._text = (parsed.content or "").strip()
 
         self._date = parsed.created
         if self._date is not None and timezone.is_naive(self._date):
@@ -281,15 +279,15 @@ class TikaDocumentParser:
     # Result accessors
     # ------------------------------------------------------------------
 
-    def get_text(self) -> str | None:
+    def get_text(self) -> str:
         """Return the plain-text content extracted during parse.
 
         Returns
         -------
-        str | None
-            Extracted text, or None if parse has not been called yet.
+        str
+            Extracted text, or an empty string if no text could be found.
         """
-        return self._text
+        return self._text or ""
 
     def get_date(self) -> datetime.datetime | None:
         """Return the document date detected during parse.

src/paperless/tests/parsers/test_remote_parser.py

@@ -319,11 +319,11 @@ class TestRemoteParserParse:
         assert remote_parser.get_text() == ""
         assert remote_parser.get_archive_path() is None
 
-    def test_get_text_none_before_parse(
+    def test_get_text_empty_before_parse(
         self,
         remote_parser: RemoteDocumentParser,
     ) -> None:
-        assert remote_parser.get_text() is None
+        assert remote_parser.get_text() == ""
 
     def test_get_date_always_none(
         self,
@@ -342,7 +342,7 @@ class TestRemoteParserParse:
 
 
 class TestRemoteParserParseError:
-    def test_parse_returns_none_on_azure_error(
+    def test_parse_returns_empty_on_azure_error(
         self,
         remote_parser: RemoteDocumentParser,
         simple_digital_pdf_file: Path,
@@ -350,7 +350,7 @@ class TestRemoteParserParseError:
     ) -> None:
         remote_parser.parse(simple_digital_pdf_file, "application/pdf")
 
-        assert remote_parser.get_text() is None
+        assert remote_parser.get_text() == ""
 
     def test_parse_closes_client_on_error(
         self,

src/paperless/tests/parsers/test_text_parser.py

@@ -138,11 +138,11 @@ class TestTextParserParse:
 
         assert text_parser.get_text() == "Pantothens\ufffdure\n"
 
-    def test_get_text_none_before_parse(
+    def test_get_text_empty_before_parse(
         self,
         text_parser: TextDocumentParser,
     ) -> None:
-        assert text_parser.get_text() is None
+        assert text_parser.get_text() == ""
 
 
 class TestTextParserThumbnail:

src/paperless/tests/test_registry.py

@@ -74,8 +74,8 @@ def dummy_parser_cls() -> type:
             Required to exist, but doesn't need to do anything
             """
 
-        def get_text(self) -> str | None:
-            return None
+        def get_text(self) -> str:
+            return ""
 
         def get_date(self) -> None:
             return None