refactor: wire up domain/chapter_overrides.py and domain/metadata_merge.py

- Update chapter_overrides.py to return tuple matching original signature
- Import apply_chapter_overrides and merge_metadata from domain modules
- Remove old function bodies from conversion_runner.py
- Add tests/test_chapter_merge_normalize.py (19 tests)
- conversion_runner.py: 1677 → 1574 lines
- All tests pass

abogen/domain/chapter_overrides.py

@@ -1,25 +1,17 @@
 from __future__ import annotations
 
-from dataclasses import dataclass
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, Tuple
 
 from abogen.text_extractor import ExtractedChapter
-
-
-@dataclass
-class ChapterOverrideResult:
-    selected: List[ExtractedChapter]
-    metadata_updates: Dict[str, str]
-    diagnostics: List[str]
+from abogen.domain.voice_utils import coerce_truthy
 
 
 def apply_chapter_overrides(
     extracted: List[ExtractedChapter],
     overrides: List[Dict[str, Any]],
-    coerce_truthy_fn,
-) -> ChapterOverrideResult:
+) -> Tuple[List[ExtractedChapter], Dict[str, str], List[str]]:
     if not overrides:
-        return ChapterOverrideResult(selected=[], metadata_updates={}, diagnostics=[])
+        return [], {}, []
 
     selected: List[ExtractedChapter] = []
     metadata_updates: Dict[str, str] = {}
@@ -32,7 +24,7 @@ def apply_chapter_overrides(
             )
             continue
 
-        enabled = coerce_truthy_fn(payload.get("enabled", True))
+        enabled = coerce_truthy(payload.get("enabled", True))
         payload["enabled"] = enabled
         if not enabled:
             continue
@@ -97,4 +89,4 @@ def apply_chapter_overrides(
 
         selected.append(ExtractedChapter(title=title_value, text=text_value))
 
-    return ChapterOverrideResult(selected=selected, metadata_updates=metadata_updates, diagnostics=diagnostics)
+    return selected, metadata_updates, diagnostics

abogen/webui/conversion_runner.py

@@ -87,6 +87,8 @@ from abogen.domain.voice_resolution import (
     chapter_voice_spec as _chapter_voice_spec,
     chunk_voice_spec as _chunk_voice_spec,
 )
+from abogen.domain.chapter_overrides import apply_chapter_overrides as _apply_chapter_overrides
+from abogen.domain.metadata_merge import merge_metadata as _merge_metadata
 
 
 from .service import Job, JobStatus
@@ -192,111 +194,6 @@ def _coerce_truthy(value: Any, default: bool = True) -> bool:
 _OUTPUT_SANITIZE_RE = re.compile(r"[^\w\-_.]+")
 
 
-def _apply_chapter_overrides(
-    extracted: List[ExtractedChapter],
-    overrides: List[Dict[str, Any]],
-) -> tuple[List[ExtractedChapter], Dict[str, str], List[str]]:
-    if not overrides:
-        return [], {}, []
-
-    selected: List[ExtractedChapter] = []
-    metadata_updates: Dict[str, str] = {}
-    diagnostics: List[str] = []
-
-    for position, payload in enumerate(overrides):
-        if not isinstance(payload, dict):
-            diagnostics.append(
-                f"Skipped chapter override at position {position + 1}: unsupported payload type {type(payload).__name__}."
-            )
-            continue
-
-        enabled = _coerce_truthy(payload.get("enabled", True))
-        payload["enabled"] = enabled
-        if not enabled:
-            continue
-
-        metadata_payload = payload.get("metadata") or {}
-        if isinstance(metadata_payload, dict):
-            for key, value in metadata_payload.items():
-                if value is None:
-                    continue
-                metadata_updates[str(key)] = str(value)
-
-        base: Optional[ExtractedChapter] = None
-        idx_candidate = payload.get("index")
-        idx_normalized: Optional[int] = None
-        if isinstance(idx_candidate, int):
-            idx_normalized = idx_candidate
-        elif isinstance(idx_candidate, str):
-            try:
-                idx_normalized = int(idx_candidate)
-            except ValueError:
-                idx_normalized = None
-        if idx_normalized is not None and 0 <= idx_normalized < len(extracted):
-            base = extracted[idx_normalized]
-            payload["index"] = idx_normalized
-
-        if base is None:
-            source_title = payload.get("source_title")
-            if isinstance(source_title, str):
-                base = next((chapter for chapter in extracted if chapter.title == source_title), None)
-
-        if base is None:
-            candidate_title = payload.get("title")
-            if isinstance(candidate_title, str):
-                base = next((chapter for chapter in extracted if chapter.title == candidate_title), None)
-
-        text_override = payload.get("text")
-        if text_override is not None:
-            text_value = str(text_override)
-        elif base is not None:
-            text_value = base.text
-        else:
-            diagnostics.append(
-                f"Skipped chapter override at position {position + 1}: no text provided and no matching source chapter found."
-            )
-            continue
-
-        title_override = payload.get("title")
-        if title_override is not None:
-            title_value = str(title_override)
-        elif base is not None:
-            title_value = base.title
-        else:
-            title_value = f"Chapter {position + 1}"
-
-        if base and not payload.get("source_title"):
-            payload["source_title"] = base.title
-
-        payload["title"] = title_value
-        payload["text"] = text_value
-        payload["characters"] = len(text_value)
-        payload.setdefault("order", payload.get("order", position))
-
-        selected.append(ExtractedChapter(title=title_value, text=text_value))
-
-    return selected, metadata_updates, diagnostics
-
-
-def _merge_metadata(
-    extracted: Optional[Dict[str, str]],
-    overrides: Dict[str, Any],
-) -> Dict[str, str]:
-    merged: Dict[str, str] = {}
-    if extracted:
-        for key, value in extracted.items():
-            if value is None:
-                continue
-            merged[str(key)] = str(value)
-    for key, value in (overrides or {}).items():
-        key_str = str(key)
-        if value is None:
-            merged.pop(key_str, None)
-        else:
-            merged[key_str] = str(value)
-    return merged
-
-
 _APOSTROPHE_CONFIG = ApostropheConfig()