feat: Implement normalize chapter opening caps feature and update related settings

abogen/web/conversion_runner.py

@@ -75,6 +75,37 @@ def _coerce_truthy(value: Any, default: bool = True) -> bool:
 
 _HEADING_SANITIZE_RE = re.compile(r"[^a-z0-9]+")
 _HEADING_NUMBER_PREFIX_RE = re.compile(r"^\s*(?P<number>(?:\d+|[ivxlcdm]+))(?P<suffix>(?:[\s.:;-].*)?)$", re.IGNORECASE)
+_ACRONYM_ALLOWLIST = {
+    "AI",
+    "API",
+    "CPU",
+    "DIY",
+    "GPU",
+    "HTML",
+    "HTTP",
+    "HTTPS",
+    "ID",
+    "JSON",
+    "MP3",
+    "MP4",
+    "M4B",
+    "NASA",
+    "OCR",
+    "PDF",
+    "SQL",
+    "TV",
+    "TTS",
+    "UK",
+    "UN",
+    "UFO",
+    "OK",
+    "URL",
+    "USA",
+    "US",
+    "VR",
+}
+_ROMAN_NUMERAL_CHARS = frozenset("IVXLCDM")
+_CAPS_WORD_RE = re.compile(r"[A-Z][A-Z0-9'\u2019-]*")
 
 
 def _simplify_heading_text(text: str) -> str:
@@ -136,6 +167,90 @@ def _strip_duplicate_heading_line(text: str, heading: str) -> tuple[str, bool]:
         new_lines.pop(0)
     return "\n".join(new_lines), True
 
+
+def _normalize_caps_word(word: str) -> str:
+    upper = word.upper()
+    letters = [char for char in upper if char.isalpha()]
+    if not letters:
+        return word
+    if upper in _ACRONYM_ALLOWLIST:
+        return word
+    if len(letters) <= 1:
+        return word
+    if all(char in _ROMAN_NUMERAL_CHARS for char in letters) and len(letters) <= 7:
+        return word
+
+    parts = re.split(r"(['\-\u2019])", word)
+    normalized_parts: List[str] = []
+    for part in parts:
+        if part in {"'", "-", "\u2019"}:
+            normalized_parts.append(part)
+            continue
+        if not part:
+            continue
+        normalized_parts.append(part[0].upper() + part[1:].lower())
+    return "".join(normalized_parts) or word
+
+
+def _normalize_chapter_opening_caps(text: str) -> tuple[str, bool]:
+    if not text:
+        return text, False
+
+    leading_len = len(text) - len(text.lstrip())
+    leading = text[:leading_len]
+    working = text[leading_len:]
+    if not working:
+        return text, False
+
+    builder: List[str] = []
+    pos = 0
+    changed = False
+
+    while pos < len(working):
+        char = working[pos]
+        if char in "\r\n":
+            builder.append(working[pos:])
+            pos = len(working)
+            break
+        if char.isspace():
+            builder.append(char)
+            pos += 1
+            continue
+        if char.islower():
+            builder.append(working[pos:])
+            pos = len(working)
+            break
+        if not char.isalpha():
+            builder.append(char)
+            pos += 1
+            continue
+
+        match = _CAPS_WORD_RE.match(working, pos)
+        if not match:
+            builder.append(char)
+            pos += 1
+            continue
+
+        word = match.group(0)
+        if any(ch.islower() for ch in word):
+            builder.append(working[pos:])
+            pos = len(working)
+            break
+
+        normalized = _normalize_caps_word(word)
+        if normalized != word:
+            changed = True
+        builder.append(normalized)
+        pos = match.end()
+
+    if pos < len(working):
+        builder.append(working[pos:])
+
+    if not changed:
+        return text, False
+
+    return leading + "".join(builder), True
+
 def _normalize_metadata_map(values: Optional[Mapping[str, Any]]) -> Dict[str, str]:
     normalized: Dict[str, str] = {}
     if not values:
@@ -1247,6 +1362,7 @@ def run_conversion_job(job: Job) -> None:
             heading_text = spoken_title or raw_title
             chapter_display_title = heading_text or f"Chapter {idx}"
             job.add_log(f"Processing chapter {idx}/{total_chapters}: {chapter_display_title}")
+            normalize_opening_caps = bool(getattr(job, "normalize_chapter_opening_caps", True))
 
             chapter_start_time = current_time
             chapter_override = (
@@ -1323,6 +1439,8 @@ def run_conversion_job(job: Job) -> None:
                 chunks_for_chapter = chunk_groups.get(idx - 1, []) if chunk_groups else []
                 body_segments = 0
                 pending_heading_strip = remove_heading_from_body
+                opening_caps_pending = normalize_opening_caps
+                opening_caps_logged = False
                 if chunks_for_chapter:
                     job.add_log(
                         f"Emitting {len(chunks_for_chapter)} {job.chunk_level} chunks for chapter {idx}.",
@@ -1337,15 +1455,34 @@ def run_conversion_job(job: Job) -> None:
                     if not chunk_text:
                         continue
 
+                    mutated_entry = False
                     if pending_heading_strip and heading_text:
                         chunk_text, removed_heading = _strip_duplicate_heading_line(chunk_text, heading_text)
                         if removed_heading:
                             pending_heading_strip = False
                             chunk_entry = dict(chunk_entry)
                             chunk_entry["normalized_text"] = chunk_text
+                            mutated_entry = True
                             if not chunk_text.strip():
                                 continue
 
+                    if opening_caps_pending and chunk_text:
+                        normalized_text, normalized_changed = _normalize_chapter_opening_caps(chunk_text)
+                        if normalized_changed:
+                            if not mutated_entry:
+                                chunk_entry = dict(chunk_entry)
+                                mutated_entry = True
+                            chunk_entry["normalized_text"] = normalized_text
+                            chunk_text = normalized_text
+                            if not opening_caps_logged:
+                                job.add_log(
+                                    f"Normalized uppercase chapter opening for chapter {idx}.",
+                                    level="debug",
+                                )
+                                opening_caps_logged = True
+                        if chunk_text.strip():
+                            opening_caps_pending = False
+
                     chunk_voice_spec = _chunk_voice_spec(
                         job,
                         chunk_entry,
@@ -1396,11 +1533,23 @@ def run_conversion_job(job: Job) -> None:
 
                 if body_segments == 0:
                     chapter_body_start = current_time
-                    chapter_text = chapter.text
+                    chapter_text = str(chapter.text or "")
                     if pending_heading_strip and heading_text:
                         chapter_text, removed_heading = _strip_duplicate_heading_line(chapter_text, heading_text)
                         if removed_heading:
                             pending_heading_strip = False
+                    if opening_caps_pending and chapter_text:
+                        normalized_body, normalized_changed = _normalize_chapter_opening_caps(chapter_text)
+                        if normalized_changed:
+                            chapter_text = normalized_body
+                            if not opening_caps_logged:
+                                job.add_log(
+                                    f"Normalized uppercase chapter opening for chapter {idx}.",
+                                    level="debug",
+                                )
+                                opening_caps_logged = True
+                        if str(chapter_text or "").strip():
+                            opening_caps_pending = False
                     emitted = emit_text(
                         chapter_text,
                         voice_choice=voice_choice,
@@ -1418,7 +1567,7 @@ def run_conversion_job(job: Job) -> None:
                                 "speaker_id": "narrator",
                                 "voice": chapter_voice_spec,
                                 "level": job.chunk_level,
-                                "characters": len(chapter.text or ""),
+                                "characters": len(chapter_text or ""),
                             }
                         )
                     elif chunks_for_chapter:

abogen/web/routes.py

@@ -1543,6 +1543,22 @@ def _apply_prepare_form(
     elif hasattr(form, "__contains__") and "read_title_intro" in form:
         pending.read_title_intro = False
 
+    caps_values: List[str] = []
+    if callable(getter):
+        raw_caps_values = getter("normalize_chapter_opening_caps")
+        if raw_caps_values:
+            caps_values = list(cast(Iterable[str], raw_caps_values))
+    else:
+        raw_caps = form.get("normalize_chapter_opening_caps")
+        if raw_caps is not None:
+            caps_values = [raw_caps]
+    if caps_values:
+        pending.normalize_chapter_opening_caps = _coerce_bool(
+            caps_values[-1], getattr(pending, "normalize_chapter_opening_caps", True)
+        )
+    elif hasattr(form, "__contains__") and "normalize_chapter_opening_caps" in form:
+        pending.normalize_chapter_opening_caps = False
+
     overrides: List[Dict[str, Any]] = []
     selected_total = 0
 
@@ -1669,6 +1685,28 @@ def _apply_book_step_form(
     else:
         pending.read_title_intro = intro_default
 
+    caps_default = (
+        pending.normalize_chapter_opening_caps
+        if isinstance(getattr(pending, "normalize_chapter_opening_caps", None), bool)
+        else bool(settings.get("normalize_chapter_opening_caps", True))
+    )
+    caps_values: List[str] = []
+    getter = getattr(form, "getlist", None)
+    if callable(getter):
+        raw_caps_values = getter("normalize_chapter_opening_caps")
+        if raw_caps_values:
+            caps_values = list(cast(Iterable[str], raw_caps_values))
+    else:
+        raw_caps_flag = form.get("normalize_chapter_opening_caps")
+        if raw_caps_flag is not None:
+            caps_values = [raw_caps_flag]
+    if caps_values:
+        pending.normalize_chapter_opening_caps = _coerce_bool(caps_values[-1], caps_default)
+    elif hasattr(form, "__contains__") and "normalize_chapter_opening_caps" in form:
+        pending.normalize_chapter_opening_caps = False
+    else:
+        pending.normalize_chapter_opening_caps = caps_default
+
     speed_value = form.get("speed")
     if speed_value is not None:
         try:
@@ -1918,6 +1956,7 @@ BOOLEAN_SETTINGS = {
     "enable_entity_recognition",
     "read_title_intro",
     "auto_prefix_chapter_titles",
+    "normalize_chapter_opening_caps",
     "normalization_numbers",
     "normalization_titles",
     "normalization_terminal",
@@ -1948,6 +1987,7 @@ def _settings_defaults() -> Dict[str, Any]:
         "silence_between_chapters": 2.0,
         "chapter_intro_delay": 0.5,
         "read_title_intro": False,
+        "normalize_chapter_opening_caps": True,
         "max_subtitle_words": 50,
         "chunk_level": "paragraph",
         "enable_entity_recognition": True,
@@ -3411,6 +3451,7 @@ def enqueue_job() -> ResponseReturnValue:
     silence_between_chapters = settings["silence_between_chapters"]
     chapter_intro_delay = settings["chapter_intro_delay"]
     read_title_intro = settings["read_title_intro"]
+    normalize_chapter_opening_caps = settings["normalize_chapter_opening_caps"]
     max_subtitle_words = settings["max_subtitle_words"]
     auto_prefix_chapter_titles = settings["auto_prefix_chapter_titles"]
 
@@ -3479,6 +3520,7 @@ def enqueue_job() -> ResponseReturnValue:
         cover_image_mime=cover_mime,
         chapter_intro_delay=chapter_intro_delay,
         read_title_intro=bool(read_title_intro),
+        normalize_chapter_opening_caps=bool(normalize_chapter_opening_caps),
         auto_prefix_chapter_titles=bool(auto_prefix_chapter_titles),
         chunk_level=chunk_level_value,
         speaker_mode=speaker_mode_value,
@@ -3760,6 +3802,7 @@ def finalize_job(pending_id: str) -> ResponseReturnValue:
         cover_image_mime=pending.cover_image_mime,
         chapter_intro_delay=pending.chapter_intro_delay,
         read_title_intro=pending.read_title_intro,
+        normalize_chapter_opening_caps=getattr(pending, "normalize_chapter_opening_caps", True),
         auto_prefix_chapter_titles=getattr(pending, "auto_prefix_chapter_titles", True),
         chunk_level=pending.chunk_level,
         chunks=processed_chunks,

abogen/web/service.py

@@ -24,7 +24,7 @@ def _create_set_event() -> threading.Event:
     return event
 
 
-STATE_VERSION = 7
+STATE_VERSION = 8
 
 
 _JOB_LOGGER = logging.getLogger("abogen.jobs")
@@ -107,6 +107,7 @@ class Job:
     chapter_intro_delay: float = 0.5
     read_title_intro: bool = False
     auto_prefix_chapter_titles: bool = True
+    normalize_chapter_opening_caps: bool = True
     status: JobStatus = JobStatus.PENDING
     started_at: Optional[float] = None
     finished_at: Optional[float] = None
@@ -175,6 +176,7 @@ class Job:
                 "chapter_intro_delay": self.chapter_intro_delay,
                 "read_title_intro": getattr(self, "read_title_intro", False),
                 "auto_prefix_chapter_titles": getattr(self, "auto_prefix_chapter_titles", True),
+                "normalize_chapter_opening_caps": getattr(self, "normalize_chapter_opening_caps", True),
             },
             "metadata_tags": dict(self.metadata_tags),
             "chapters": [
@@ -239,6 +241,7 @@ class PendingJob:
     chapter_intro_delay: float = 0.5
     read_title_intro: bool = False
     auto_prefix_chapter_titles: bool = True
+    normalize_chapter_opening_caps: bool = True
     chunk_level: str = "paragraph"
     chunks: List[Dict[str, Any]] = field(default_factory=list)
     speakers: Dict[str, Any] = field(default_factory=dict)
@@ -320,6 +323,7 @@ class ConversionService:
             chapter_intro_delay: float = 0.5,
             read_title_intro: bool = False,
             auto_prefix_chapter_titles: bool = True,
+            normalize_chapter_opening_caps: bool = True,
         chunk_level: str = "paragraph",
         chunks: Optional[Iterable[Any]] = None,
         speakers: Optional[Mapping[str, Any]] = None,
@@ -368,6 +372,7 @@ class ConversionService:
             chapter_intro_delay=chapter_intro_delay,
             read_title_intro=bool(read_title_intro),
             auto_prefix_chapter_titles=bool(auto_prefix_chapter_titles),
+            normalize_chapter_opening_caps=bool(normalize_chapter_opening_caps),
             chunk_level=chunk_level,
             chunks=normalized_chunks,
             speakers=dict(speakers or {}),
@@ -524,6 +529,7 @@ class ConversionService:
                 chapter_intro_delay=job.chapter_intro_delay,
                 read_title_intro=job.read_title_intro,
                 auto_prefix_chapter_titles=job.auto_prefix_chapter_titles,
+                normalize_chapter_opening_caps=job.normalize_chapter_opening_caps,
                 chunk_level=job.chunk_level,
                 chunks=job.chunks,
                 speakers=job.speakers,
@@ -751,6 +757,7 @@ class ConversionService:
             "chapter_intro_delay": job.chapter_intro_delay,
             "read_title_intro": job.read_title_intro,
             "auto_prefix_chapter_titles": job.auto_prefix_chapter_titles,
+            "normalize_chapter_opening_caps": job.normalize_chapter_opening_caps,
             "chunk_level": job.chunk_level,
             "chunks": [dict(entry) for entry in job.chunks],
             "speakers": dict(job.speakers),
@@ -844,6 +851,7 @@ class ConversionService:
             chapter_intro_delay=float(payload.get("chapter_intro_delay", 0.5)),
             read_title_intro=bool(payload.get("read_title_intro", False)),
             auto_prefix_chapter_titles=bool(payload.get("auto_prefix_chapter_titles", True)),
+            normalize_chapter_opening_caps=bool(payload.get("normalize_chapter_opening_caps", True)),
         )
         job.status = JobStatus(payload.get("status", job.status.value))
         job.started_at = payload.get("started_at")
@@ -898,7 +906,8 @@ class ConversionService:
         except Exception:
             return
 
-        if payload.get("version") != STATE_VERSION:
+        version = int(payload.get("version", 0) or 0)
+        if version not in {STATE_VERSION, STATE_VERSION - 1}:
             return
 
         jobs_payload = payload.get("jobs", [])

abogen/web/templates/job_detail.html

@@ -25,6 +25,7 @@
         <li><strong>Silence between chapters:</strong> {{ '%.1f'|format(job.silence_between_chapters) }}s</li>
         <li><strong>Chapter intro delay:</strong> {{ '%.1f'|format(job.chapter_intro_delay) }}s</li>
         <li><strong>Title intro:</strong> {{ 'Yes' if job.read_title_intro else 'No' }}</li>
+        <li><strong>Normalize chapter openings:</strong> {{ 'Yes' if job.normalize_chapter_opening_caps else 'No' }}</li>
         <li><strong>Prefix chapter titles:</strong> {{ 'Yes' if job.auto_prefix_chapter_titles else 'No' }}</li>
         <li><strong>Max words per subtitle:</strong> {{ job.max_subtitle_words }}</li>
         <li><strong>Project folder:</strong> {{ 'Yes' if job.save_as_project else 'No' }}</li>

abogen/web/templates/partials/new_job_step_book.html

@@ -65,6 +65,16 @@
     {% set read_title_intro = settings_dict.get('read_title_intro', False) %}
   {% endif %}
 {% endif %}
+{% set normalize_caps_value = form_values.get('normalize_chapter_opening_caps') if form_values else None %}
+{% if normalize_caps_value is not none %}
+  {% set normalize_chapter_opening_caps = ((normalize_caps_value|string)|lower) in ['true', '1', 'yes', 'on'] %}
+{% else %}
+  {% if pending is not none %}
+    {% set normalize_chapter_opening_caps = pending.normalize_chapter_opening_caps %}
+  {% else %}
+    {% set normalize_chapter_opening_caps = settings_dict.get('normalize_chapter_opening_caps', True) %}
+  {% endif %}
+{% endif %}
 {% set selected_config = form_values.get('speaker_config') if form_values else None %}
 {% if selected_config is none %}
   {% if pending and pending.applied_speaker_config %}
@@ -283,6 +293,14 @@
           </label>
           <p class="hint">When enabled, the narrator speaks the book title and author list before chapter one begins.</p>
         </div>
+        <div class="field field--stack">
+          <label class="toggle-pill">
+            <input type="hidden" name="normalize_chapter_opening_caps" value="false">
+            <input type="checkbox" name="normalize_chapter_opening_caps" value="true" {% if normalize_chapter_opening_caps %}checked{% endif %} {{ 'disabled' if readonly else '' }}>
+            <span>Normalize ALL CAPS chapter openings</span>
+          </label>
+          <p class="hint">Converts opening sentences written in uppercase to sentence case while keeping acronyms like AI intact.</p>
+        </div>
       </div>
     </section>
   </div>

abogen/web/templates/partials/new_job_step_chapters.html

@@ -13,6 +13,7 @@
     <input type="hidden" name="speaker_analysis_threshold" value="{{ pending.speaker_analysis_threshold }}">
     <input type="hidden" name="chapter_intro_delay" value="{{ '%.2f'|format(pending.chapter_intro_delay) }}">
     <input type="hidden" name="read_title_intro" value="{{ 'true' if pending.read_title_intro else 'false' }}">
+  <input type="hidden" name="normalize_chapter_opening_caps" value="{{ 'true' if pending.normalize_chapter_opening_caps else 'false' }}">
     {% if pending.generate_epub3 %}
       <input type="hidden" name="generate_epub3" value="true">
     {% endif %}

abogen/web/templates/partials/new_job_step_entities.html

@@ -26,6 +26,7 @@
     <input type="hidden" name="speaker_analysis_threshold" value="{{ pending.speaker_analysis_threshold }}">
     <input type="hidden" name="chapter_intro_delay" value="{{ '%.2f'|format(pending.chapter_intro_delay) }}">
     <input type="hidden" name="read_title_intro" value="{{ 'true' if pending.read_title_intro else 'false' }}">
+  <input type="hidden" name="normalize_chapter_opening_caps" value="{{ 'true' if pending.normalize_chapter_opening_caps else 'false' }}">
     {% if pending.generate_epub3 %}
       <input type="hidden" name="generate_epub3" value="true">
     {% endif %}

abogen/web/templates/prepare_chapters.html

@@ -53,6 +53,7 @@
         <input type="hidden" name="speaker_analysis_threshold" value="{{ pending.speaker_analysis_threshold }}">
         <input type="hidden" name="chapter_intro_delay" value="{{ '%.2f'|format(pending.chapter_intro_delay) }}">
         <input type="hidden" name="read_title_intro" value="{{ 'true' if pending.read_title_intro else 'false' }}">
+  <input type="hidden" name="normalize_chapter_opening_caps" value="{{ 'true' if pending.normalize_chapter_opening_caps else 'false' }}">
         {% if pending.generate_epub3 %}
           <input type="hidden" name="generate_epub3" value="true">
         {% endif %}

abogen/web/templates/settings.html

@@ -130,6 +130,13 @@
               </label>
               <p class="hint">When enabled, the narrator speaks the title, optional subtitle, and author names before chapter one.</p>
             </div>
+            <div class="field field--stack">
+              <label class="toggle-pill">
+                <input type="checkbox" name="normalize_chapter_opening_caps" value="true" {% if settings.normalize_chapter_opening_caps %}checked{% endif %}>
+                <span>Normalize ALL CAPS Chapter Openings</span>
+              </label>
+              <p class="hint">Converts screaming uppercase openings to sentence case while preserving acronyms.</p>
+            </div>
             <div class="field field--stack">
               <label class="toggle-pill">
                 <input type="checkbox" name="auto_prefix_chapter_titles" value="true" {% if settings.auto_prefix_chapter_titles %}checked{% endif %}>

tests/test_conversion_chapter_titles.py

@@ -1,6 +1,70 @@
+import sys
+import types
+
+if "soundfile" not in sys.modules:
+    soundfile_stub = types.ModuleType("soundfile")
+
+    class _SoundFileStub:  # pragma: no cover - placeholder to satisfy imports
+        def __init__(self, *args: object, **kwargs: object) -> None:
+            raise RuntimeError("soundfile is not installed in the test environment")
+
+    soundfile_stub.SoundFile = _SoundFileStub  # type: ignore[attr-defined]
+    sys.modules["soundfile"] = soundfile_stub
+
+if "static_ffmpeg" not in sys.modules:
+    sys.modules["static_ffmpeg"] = types.ModuleType("static_ffmpeg")
+
+if "ebooklib" not in sys.modules:
+    ebooklib_stub = types.ModuleType("ebooklib")
+    ebooklib_epub_stub = types.ModuleType("ebooklib.epub")
+    ebooklib_stub.epub = ebooklib_epub_stub  # type: ignore[attr-defined]
+    sys.modules["ebooklib"] = ebooklib_stub
+    sys.modules["ebooklib.epub"] = ebooklib_epub_stub
+
+if "fitz" not in sys.modules:
+    sys.modules["fitz"] = types.ModuleType("fitz")
+
+if "markdown" not in sys.modules:
+    markdown_stub = types.ModuleType("markdown")
+
+    class _MarkdownStub:
+        def __init__(self, *args: object, **kwargs: object) -> None:
+            self.toc_tokens = []
+
+        def convert(self, text: str) -> str:
+            return text
+
+    markdown_stub.Markdown = _MarkdownStub  # type: ignore[attr-defined]
+    sys.modules["markdown"] = markdown_stub
+
+if "bs4" not in sys.modules:
+    bs4_stub = types.ModuleType("bs4")
+
+    class _BeautifulSoupStub:
+        def __init__(self, *args: object, **kwargs: object) -> None:
+            self._text = ""
+
+        def find(self, *args: object, **kwargs: object) -> None:
+            return None
+
+        def get_text(self) -> str:
+            return self._text
+
+        def decompose(self) -> None:  # pragma: no cover - compatibility shim
+            return None
+
+    class _NavigableStringStub(str):
+        pass
+
+    bs4_stub.BeautifulSoup = _BeautifulSoupStub  # type: ignore[attr-defined]
+    bs4_stub.NavigableString = _NavigableStringStub  # type: ignore[attr-defined]
+    sys.modules["bs4"] = bs4_stub
+
+
 from abogen.web.conversion_runner import (
     _format_spoken_chapter_title,
     _headings_equivalent,
+    _normalize_chapter_opening_caps,
     _strip_duplicate_heading_line,
 )
 
@@ -29,3 +93,27 @@ def test_strip_duplicate_heading_line_removes_first_match() -> None:
     text, removed = _strip_duplicate_heading_line("Chapter 3: Intro\nBody text", "Chapter 3: Intro")
     assert removed is True
     assert text.strip() == "Body text"
+
+
+def test_normalize_chapter_opening_caps_basic_title() -> None:
+    normalized, changed = _normalize_chapter_opening_caps("ALL CAPS TITLE")
+    assert normalized == "All Caps Title"
+    assert changed is True
+
+
+def test_normalize_chapter_opening_caps_respects_acronyms() -> None:
+    normalized, changed = _normalize_chapter_opening_caps("NASA MISSION LOG")
+    assert normalized == "NASA Mission Log"
+    assert changed is True
+
+
+def test_normalize_chapter_opening_caps_handles_roman_numerals() -> None:
+    normalized, changed = _normalize_chapter_opening_caps("IV. THE RETURN")
+    assert normalized == "IV. The Return"
+    assert changed is True
+
+
+def test_normalize_chapter_opening_caps_keeps_mixed_case() -> None:
+    normalized, changed = _normalize_chapter_opening_caps("Already Mixed Case")
+    assert normalized == "Already Mixed Case"
+    assert changed is False

tests/test_prepare_form.py

@@ -33,6 +33,7 @@ def _make_pending_job() -> PendingJob:
         chapters=[],
         created_at=0.0,
         read_title_intro=False,
+        normalize_chapter_opening_caps=True,
     )