subtitler 2.6.1

Parse, convert, validate, edit, and generate subtitles in 15 formats (SRT, VTT, ASS/SSA, MicroDVD, SubViewer, TTML, SBV, LRC, SAMI, MPL2, SCC, EBU STL, DFXP, Whisper JSON). Full CLI included.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104

//! Property-based tests for subtitle round-trips and invariants.
//!
//! Run: PROPTEST_CASES=100 cargo test --test proptest
//!
//! Gated behind cfg(not(wasm32)) because proptest's transitive
//! dependencies (wait-timeout) do not support wasm32-unknown-unknown.

#![cfg(not(target_arch = "wasm32"))]

use proptest::prelude::*;
use subtitler::model::Subtitle;
use subtitler::model::SubtitleFile;
use subtitler::model::SubtitleFormat;

fn arb_subtitle() -> impl Strategy<Value = Subtitle> {
  (
    0u64..3_600_000u64,
    0u64..3_600_000u64,
    // Text: expanded from original ASCII-only to include Latin-1+ and
    // Unicode CJK/emoji ranges. Excludes < > & (tag markers) and \n \r
    // (multi-cue splitting) to keep round-trip comparisons simple.
    "[\x20-\x7E\u{80}-\u{FF}\u{4E00}-\u{9FFF}\u{3040}-\u{309F}]{0,60}",
  )
    .prop_map(|(start, end, text)| {
      let (s, e) = if start <= end {
        (start, end)
      } else {
        (end, start)
      };
      Subtitle::new(s, e, &text)
    })
}

fn arb_subtitle_file(n: usize) -> impl Strategy<Value = SubtitleFile> {
  proptest::collection::vec(arb_subtitle(), n..=n).prop_map(SubtitleFile::Srt)
}

proptest! {
  #[test]
  fn srt_round_trip_preserves_text_and_times(sub in arb_subtitle()) {
    let s = subtitler::srt::to_string(std::slice::from_ref(&sub));
    let parsed = subtitler::srt::parse_content(&s).unwrap();
    prop_assert_eq!(parsed.subtitles().len(), 1);
    prop_assert_eq!(parsed.subtitles()[0].start, sub.start);
    prop_assert_eq!(parsed.subtitles()[0].end, sub.end);
    prop_assert_eq!(parsed.subtitles()[0].text.trim(), sub.text.trim());
  }

  #[test]
  fn vtt_round_trip_preserves_text_and_times(sub in arb_subtitle()) {
    let s = subtitler::vtt::to_string(std::slice::from_ref(&sub), None);
    let parsed = subtitler::vtt::parse_content(&s).unwrap();
    prop_assert_eq!(parsed.subtitles().len(), 1);
    prop_assert_eq!(parsed.subtitles()[0].start, sub.start);
    prop_assert_eq!(parsed.subtitles()[0].end, sub.end);
    prop_assert_eq!(parsed.subtitles()[0].text.trim(), sub.text.trim());
  }

  #[test]
  fn ass_round_trip_preserves_count(sub in arb_subtitle()) {
    let s = subtitler::ass::to_string(
      &std::collections::HashMap::new(),
      &[subtitler::model::AssStyle::default_style()],
      std::slice::from_ref(&sub),
    );
    let parsed = subtitler::ass::parse_content(&s).unwrap();
    prop_assert_eq!(parsed.subtitles().len(), 1);
  }

  // ── Idempotency properties ──

  #[test]
  fn sort_is_idempotent(file in arb_subtitle_file(10)) {
    let mut a = file.clone();
    a.sort();
    let mut b = a.clone();
    b.sort();
    prop_assert_eq!(a.subtitles().len(), b.subtitles().len());
    for (x, y) in a.subtitles().iter().zip(b.subtitles().iter()) {
      prop_assert_eq!(x.start, y.start);
      prop_assert_eq!(x.end, y.end);
    }
  }

  #[test]
  fn shift_all_is_reversible(sub in arb_subtitle()) {
    let mut a = sub.clone();
    a.shift(3000);
    a.shift(-3000);
    prop_assert_eq!(a.start, sub.start);
    prop_assert_eq!(a.end, sub.end);
  }

  #[test]
  fn merge_adjacent_never_increases_count(file in arb_subtitle_file(8)) {
    let mut m = file.clone();
    m.sort();
    m.merge_adjacent(1000);
    prop_assert!(m.subtitles().len() <= file.subtitles().len(),
      "merge_adjacent should not increase cue count: {} -> {}",
      file.subtitles().len(), m.subtitles().len()
    );
  }
}