Previously only the content-sniff path stripped the BOM; the suffix path
relied on its callers (fromExternalFile via UTF8Reader) having already
stripped it. That implicit contract was fragile — a caller passing raw
BOM-prefixed bytes with a suffix would reach the parsers with the BOM intact
(SanitizeText does not strip it). Strip once at entry so every path and
parser sees clean bytes regardless of caller. No-op for already-stripped
input.
Move the TTML <tt>-document gate into parseTTMLWithDefaultLang itself (after
the encoding fixup, so UTF-16-declared docs are still recognized): non-TTML
content returns (nil, nil) to skip; a malformed <tt> document still errors.
SRT and Lyricsfile YAML already self-skip. With every structured parser
self-skipping, the format table drops to one {suffixes, parse} column named
lyricFormats — no bySuffix/byContent split, no separate sniff-only TTML gate.
Both the suffix and content-sniff paths share the same parser per format.
Collapse the bySuffix map and sniffOrder slice into one ordered registry:
slice order is the content-sniff probe order, each row's suffixes drive
sidecar dispatch, and per-row bySuffix/byContent parsers preserve the
gated-TTML-when-sniffing distinction. One source of truth, no duplicated
parser references.
Apply thermo-nuclear review findings (behavior-preserving):
- Replace the suffix switch + three single-use closure adapters
(parseTTMLKnown/parseSRTKnown + inline YAML closure) with a
bySuffix map of a single lyricParser(lang, contents) signature.
Normalize parseTTMLWithDefaultLang/parseSRTWithLanguage to that
(lang, contents) order so no adapter glue is needed.
- Collapse the parallel sniffLyrics engine into one parseFirstMatch
primitive shared by both the suffix and content-sniff paths
(sniffOrder candidate list). TTML stays gated via parseTTMLIfDocument
in sniff mode to avoid running the XML decoder on plain/LRC text.
- Add LyricList.MarshalJSON so empty/nil always serializes to [] (the
lyrics column invariant), in one canonical place. Delete the
migration's nil-guard, which the marshaler now subsumes.
Behavior verified unchanged: full suite + race + e2e green.
