refactor(release): make tech_string a derived property

ParsedRelease.tech_string was a stored str field re-computed in two
places (assemble() at parse time, enrich_from_probe() after the probe).
The second site was a reactive fix (e79ca46) for filename builders that
saw a stale value. Turn it into an @property so it stays in sync with
quality/source/codec by construction.

- Drop the field from the dataclass + the key from assemble()'s dict.
- Drop tech_string="" from parse_release's malformed-name fallback.
- Drop the manual recomputation at the end of enrich_from_probe.
- Inject the property into asdict() result in the fixtures runner
  (same treatment as is_season_pack).
- Update tests that passed tech_string= to the constructor; rewrite the
  TestTechString case that mutated p.tech_string manually.

CHANGELOG.md

@@ -57,6 +57,17 @@ callers).
 
 ### Changed
 
+- **`ParsedRelease.tech_string` is now a derived `@property`**
+  (`alfred/domain/release/value_objects.py`). It computes
+  `quality.source.codec` joined by dots on every access, so it stays in
+  sync with the underlying fields by construction. The stored field is
+  gone from the dataclass, the dict returned by `assemble()` no longer
+  carries the key, `parse_release`'s malformed-name fallback drops the
+  `tech_string=""` kwarg, and `enrich_from_probe` no longer re-derives
+  it after filling `quality`/`source`/`codec`. Closes the
+  parser/enrichment double-source-of-truth that `e79ca46` had to fix
+  reactively. The fixtures runner now injects `tech_string` alongside
+  `is_season_pack` since `asdict()` skips properties.
 - **`RuleScope.level` is now an enum (`RuleScopeLevel`).** The set of
   valid levels (global, release_group, movie, show, season, episode)
   was documented only in a docstring comment and validated nowhere.

alfred/application/release/enrich_from_probe.py

@@ -81,9 +81,6 @@ def enrich_from_probe(parsed: ParsedRelease, info: MediaInfo) -> None:
             if lang.lower() != "und" and lang.upper() not in existing:
                 parsed.languages.append(lang)
 
-    # Re-derive tech_string so filename builders see the enriched
-    # quality/source/codec. Built the same way as in the parser pipeline:
-    # the non-None parts joined by dots, in order.
-    parsed.tech_string = ".".join(
-        p for p in (parsed.quality, parsed.source, parsed.codec) if p
-    )
+    # tech_string is a derived property on ParsedRelease — it always
+    # reflects the current quality/source/codec, so there's nothing to
+    # refresh after enrichment.

alfred/domain/release/parser/pipeline.py

@@ -713,9 +713,6 @@ def assemble(
             if distributor is None:
                 distributor = tok.text.upper()
 
-    tech_parts = [p for p in (quality, source, codec) if p]
-    tech_string = ".".join(tech_parts)
-
     # Media type heuristic. Doc/concert/integrale tokens win over the
     # generic tech-based fallback. We look across all tokens (not just
     # annotated ones) because these markers may be tagged UNKNOWN by the
@@ -754,7 +751,6 @@ def assemble(
         "source": source,
         "codec": codec,
         "group": group,
-        "tech_string": tech_string,
         "media_type": media_type,
         "site_tag": site_tag,
         "languages": languages,

alfred/domain/release/services.py

@@ -73,7 +73,6 @@ def parse_release(
             source=None,
             codec=None,
             group="UNKNOWN",
-            tech_string="",
             media_type=MediaTypeToken.UNKNOWN,
             site_tag=site_tag,
             parse_path=ParsePath.AI,

alfred/domain/release/value_objects.py

@@ -123,7 +123,6 @@ class ParsedRelease:
     source: str | None  # WEBRip, BluRay, …
     codec: str | None  # x265, HEVC, …
     group: str  # release group, "UNKNOWN" if missing
-    tech_string: str  # quality.source.codec joined with dots
     media_type: MediaTypeToken = MediaTypeToken.UNKNOWN
     site_tag: str | None = (
         None  # site watermark stripped from name, e.g. "TGx", "OxTorrent.vc"
@@ -179,6 +178,15 @@ class ParsedRelease:
     def is_season_pack(self) -> bool:
         return self.season is not None and self.episode is None
 
+    @property
+    def tech_string(self) -> str:
+        """``quality.source.codec`` joined by dots, skipping ``None`` parts.
+
+        Derived on every access so it stays in sync with the underlying
+        fields — no manual refresh needed after enrichment.
+        """
+        return ".".join(p for p in (self.quality, self.source, self.codec) if p)
+
     def show_folder_name(self, tmdb_title_safe: str, tmdb_year: int) -> str:
         """
         Build the series root folder name.

tests/application/test_enrich_from_probe.py

@@ -46,7 +46,6 @@ def _bare(**overrides) -> ParsedRelease:
         source=None,
         codec=None,
         group="UNKNOWN",
-        tech_string="",
     )
     defaults.update(overrides)
     return ParsedRelease(**defaults)
@@ -218,8 +217,9 @@ class TestLanguages:
 
 
 class TestTechString:
-    """tech_string drives the filename builders; it must be re-derived
-    whenever quality / source / codec change."""
+    """tech_string is a derived property on ParsedRelease: it always
+    reflects the current quality/source/codec. Enrichment never writes
+    it directly — it stays in sync by construction."""
 
     def test_rebuilt_from_filled_quality_and_codec(self):
         p = _bare()
@@ -239,9 +239,9 @@ class TestTechString:
         assert p.tech_string == "1080p.BluRay.x265"
 
     def test_unchanged_when_no_enrichable_video_info(self):
-        # No video info → nothing to fill → tech_string stays as it was.
+        # No video info → nothing to fill → derived tech_string stays as it was.
         p = _bare(quality="2160p", source="WEB-DL", codec="x265")
-        p.tech_string = "2160p.WEB-DL.x265"
+        assert p.tech_string == "2160p.WEB-DL.x265"
         enrich_from_probe(p, MediaInfo())
         assert p.tech_string == "2160p.WEB-DL.x265"
 

tests/domain/release/test_parser_v2_easy.py

@@ -123,7 +123,6 @@ class TestAssemble:
         assert fields["source"] == "WEBRip"
         assert fields["codec"] == "x265"
         assert fields["group"] == "KONTRAST"
-        assert fields["tech_string"] == "1080p.WEBRip.x265"
         assert fields["media_type"] == "movie"
         assert fields["site_tag"] is None
 
@@ -150,7 +149,8 @@ class TestAssemble:
         assert fields["season"] == 2
         assert fields["episode"] is None  # season pack
         assert fields["source"] is None  # ELiTE omits it
-        assert fields["tech_string"] == "1080p.x265"
+        assert fields["quality"] == "1080p"
+        assert fields["codec"] == "x265"
         assert fields["group"] == "ELiTE"
 
 

tests/domain/release/test_parser_v2_scoring.py

@@ -78,7 +78,6 @@ def _movie(year: int = 2020, **overrides) -> ParsedRelease:
         source="BluRay",
         codec="x264",
         group="GROUP",
-        tech_string="1080p.BluRay.x264",
         media_type=MediaTypeToken.MOVIE,
         parse_path=ParsePath.DIRECT,
     )
@@ -120,7 +119,6 @@ class TestComputeScore:
             source="WEBRip",
             codec="x265",
             group="KONTRAST",
-            tech_string="1080p.WEBRip.x265",
             media_type=MediaTypeToken.TV_SHOW,
             parse_path=ParsePath.DIRECT,
         )
@@ -231,7 +229,6 @@ class TestCollectors:
             source=None,
             codec=None,
             group="UNKNOWN",
-            tech_string="",
             media_type=MediaTypeToken.UNKNOWN,
             parse_path=ParsePath.DIRECT,
         )

tests/domain/test_release_fixtures.py

@@ -44,8 +44,10 @@ def test_parse_matches_fixture(fixture: ReleaseFixture, tmp_path) -> None:
 
     parsed, _report = parse_release(fixture.release_name, _KB)
     result = asdict(parsed)
-    # ``is_season_pack`` is a @property — asdict() does not include it.
+    # ``is_season_pack`` and ``tech_string`` are @property values —
+    # ``asdict()`` does not include them.
     result["is_season_pack"] = parsed.is_season_pack
+    result["tech_string"] = parsed.tech_string
 
     for field, expected in fixture.expected_parsed.items():
         assert field in result, (