debpalashandClaude Opus 4.8
f3286c5e6e
After transcription the user can paste a translation produced elsewhere (ChatGPT, DeepL, a human translator) and have it map onto the segments that already exist — no re-transcription, no timing loss. Three input shapes are auto-detected: a timestamped .srt/.vtt (cues matched to segments by time overlap, greedy one-to-one so one long cue can't be copied onto several rows), numbered lines (`1.` / `2)` / `[3]`, mapped by number and falling back to order when a model renumbers mid-answer), and plain lines (positional, blank lines treated as separators rather than empty translations). Nothing is applied until the preview dialog has shown every row as before→after with unmatched rows flagged. Applying goes through `pasteTranslations` in useSegmentEditing, which mirrors `segmentEditField`'s duties across rows in ONE undo step: write `text` and `translations[dubLangCode]` in lock-step and clear the stale machine-translation badges. It never writes `text_original` (the translate source `handleTranslateAll` reads — overwriting it would poison every later re-translate) and never touches a language other than the active one. Changing `text` alone marks those rows stale via the existing per-language fingerprints, so no new flag is needed. The new `POST /dub/parse-subtitle-text` is a stateless wrapper over the existing `services.srt_parser.parse_srt`, so the lenient cue parsing stays single-sourced instead of being reimplemented in JavaScript. Also fixes a ReDoS in that parser, reachable today via /dub/import-srt: `_TIMING_RE` used `^\s*` under re.MULTILINE, so at every line start the engine consumed all remaining blank lines before failing on the first digit — quadratic. 20k blank lines already took 1.7s and a 2 MB blank-line file never returned, pinning the request thread. Horizontal-whitespace-only classes make the scan linear. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
192 lines
5.2 KiB
Python
192 lines
5.2 KiB
Python
"""Unit tests for the SRT parser used by /dub/import-srt."""
|
||
import sys
|
||
import os
|
||
import pytest
|
||
|
||
sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "backend"))
|
||
|
||
from services.srt_parser import parse_srt # noqa: E402
|
||
|
||
|
||
def test_parses_a_well_formed_srt_file():
|
||
srt = """1
|
||
00:00:01,000 --> 00:00:04,500
|
||
Hello world.
|
||
|
||
2
|
||
00:00:05,250 --> 00:00:08,000
|
||
Second line here.
|
||
"""
|
||
result = parse_srt(srt)
|
||
assert result.skipped_cues == 0
|
||
assert result.dropped_overlaps == 0
|
||
assert len(result.segments) == 2
|
||
assert result.segments[0]["start"] == 1.0
|
||
assert result.segments[0]["end"] == 4.5
|
||
assert result.segments[0]["text"] == "Hello world."
|
||
assert result.segments[1]["start"] == 5.25
|
||
assert result.segments[1]["text"] == "Second line here."
|
||
|
||
|
||
def test_joins_multi_line_cues_with_newline():
|
||
srt = """1
|
||
00:00:01,000 --> 00:00:04,000
|
||
Line one
|
||
Line two
|
||
"""
|
||
result = parse_srt(srt)
|
||
assert result.segments[0]["text"] == "Line one\nLine two"
|
||
|
||
|
||
def test_accepts_dot_as_milliseconds_separator():
|
||
# WebVTT-style timestamps inside an SRT file are common in the wild.
|
||
srt = """1
|
||
00:00:01.500 --> 00:00:03.250
|
||
Dotty.
|
||
"""
|
||
result = parse_srt(srt)
|
||
assert result.segments[0]["start"] == 1.5
|
||
assert result.segments[0]["end"] == 3.25
|
||
|
||
|
||
def test_handles_utf8_bom_at_start_of_file():
|
||
srt = "1\n00:00:01,000 --> 00:00:02,000\nBOM cue.\n"
|
||
result = parse_srt(srt)
|
||
assert len(result.segments) == 1
|
||
assert result.segments[0]["text"] == "BOM cue."
|
||
|
||
|
||
def test_handles_crlf_line_endings():
|
||
srt = "1\r\n00:00:01,000 --> 00:00:02,000\r\nWindows.\r\n\r\n"
|
||
result = parse_srt(srt)
|
||
assert len(result.segments) == 1
|
||
|
||
|
||
def test_skips_cue_with_non_positive_duration():
|
||
srt = """1
|
||
00:00:05,000 --> 00:00:05,000
|
||
Zero duration.
|
||
|
||
2
|
||
00:00:06,000 --> 00:00:05,500
|
||
End before start.
|
||
|
||
3
|
||
00:00:07,000 --> 00:00:08,000
|
||
Good cue.
|
||
"""
|
||
result = parse_srt(srt)
|
||
assert result.skipped_cues == 2
|
||
assert len(result.segments) == 1
|
||
assert result.segments[0]["text"] == "Good cue."
|
||
|
||
|
||
def test_skips_cue_with_only_whitespace_body():
|
||
srt = """1
|
||
00:00:01,000 --> 00:00:02,000
|
||
|
||
|
||
2
|
||
00:00:03,000 --> 00:00:04,000
|
||
Real text.
|
||
"""
|
||
result = parse_srt(srt)
|
||
assert result.skipped_cues == 1
|
||
assert len(result.segments) == 1
|
||
|
||
|
||
def test_shifts_overlapping_cue_to_keep_both():
|
||
# Cue 2 starts inside cue 1; we expect cue 2's start to be pushed
|
||
# forward to cue 1's end so both still play, in order.
|
||
srt = """1
|
||
00:00:01,000 --> 00:00:05,000
|
||
First.
|
||
|
||
2
|
||
00:00:03,000 --> 00:00:07,000
|
||
Second.
|
||
"""
|
||
result = parse_srt(srt)
|
||
assert len(result.segments) == 2
|
||
assert result.segments[1]["start"] == 5.0
|
||
assert result.segments[1]["end"] == 7.0
|
||
assert result.dropped_overlaps == 0
|
||
|
||
|
||
def test_drops_overlap_that_would_have_negative_duration():
|
||
srt = """1
|
||
00:00:01,000 --> 00:00:10,000
|
||
First.
|
||
|
||
2
|
||
00:00:03,000 --> 00:00:08,000
|
||
Second entirely inside first.
|
||
"""
|
||
result = parse_srt(srt)
|
||
assert len(result.segments) == 1
|
||
assert result.dropped_overlaps == 1
|
||
|
||
|
||
def test_parses_missing_index_numbers():
|
||
# No "1", "2" lines — just timings + text. This happens with some
|
||
# subtitle editors that strip indices.
|
||
srt = """00:00:01,000 --> 00:00:02,000
|
||
First.
|
||
|
||
00:00:03,000 --> 00:00:04,000
|
||
Second.
|
||
"""
|
||
result = parse_srt(srt)
|
||
assert len(result.segments) == 2
|
||
|
||
|
||
def test_returns_empty_result_for_empty_input():
|
||
assert parse_srt("").segments == []
|
||
assert parse_srt("").skipped_cues == 0
|
||
|
||
|
||
def test_blank_line_flood_parses_in_linear_time():
|
||
# Regression: the timing-line regex used `^\s*` under re.MULTILINE, so at
|
||
# every one of N line starts the engine consumed all remaining blank
|
||
# lines before failing — quadratic. 20k blank lines already took ~1.7s
|
||
# and a 2 MB blank-line file never returned, pinning the request thread
|
||
# (reachable from /dub/import-srt with a mis-saved export, and from the
|
||
# pasted-text endpoint). Horizontal-whitespace-only classes make it
|
||
# linear: this input parses in milliseconds.
|
||
import time
|
||
|
||
srt = "1\n00:00:01,000 --> 00:00:02,000\nOnly cue.\n" + "\n" * 400_000
|
||
started = time.monotonic()
|
||
result = parse_srt(srt)
|
||
elapsed = time.monotonic() - started
|
||
assert len(result.segments) == 1
|
||
assert result.segments[0]["text"] == "Only cue."
|
||
# Pre-fix this was minutes; the bound is loose enough for a slow CI box
|
||
# and still ~3 orders of magnitude under the quadratic behaviour.
|
||
assert elapsed < 5.0, f"parse_srt took {elapsed:.1f}s — quadratic scan is back"
|
||
|
||
|
||
def test_timing_line_tolerates_leading_and_inner_spaces():
|
||
# The linearity fix narrowed `\s*` to horizontal whitespace; indented
|
||
# cues and extra spaces around the arrow must still parse.
|
||
srt = " \t00:00:01,000 --> \t00:00:02,000\nIndented.\n"
|
||
result = parse_srt(srt)
|
||
assert len(result.segments) == 1
|
||
assert result.segments[0]["text"] == "Indented."
|
||
|
||
|
||
def test_segments_get_sequential_ids_and_required_fields():
|
||
srt = """1
|
||
00:00:01,000 --> 00:00:02,000
|
||
A
|
||
|
||
2
|
||
00:00:03,000 --> 00:00:04,000
|
||
B
|
||
"""
|
||
result = parse_srt(srt)
|
||
for i, seg in enumerate(result.segments):
|
||
assert seg["id"] == i
|
||
assert seg["text"] == seg["text_original"]
|
||
assert seg["speaker_id"] == "Speaker 1"
|