fmtview 0.3.2

Fast CLI viewer for highlighting, search, and diffs across JSON, JSONL, markup, Markdown, TOML, text, and Jinja
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
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129

use super::{
    DiffChange, DiffLayout, DiffModel, SideDiffRow, UnifiedDiffRow, inline::INLINE_DIFF_PAIR_BUDGET,
};
use std::{hint::black_box, time::Instant};

#[test]
fn parses_unified_diff_line_numbers() {
    let patch = "\
--- left
+++ right
@@ -2,3 +2,4 @@
 keep
-old
+new
+added
 tail
";
    let model = DiffModel::from_unified_patch("left".to_owned(), "right".to_owned(), patch);

    assert!(model.has_changes());
    assert_eq!(model.changed_rows(DiffLayout::Unified), &[1, 2, 3]);
    assert_eq!(model.changed_rows(DiffLayout::SideBySide), &[1, 2]);
    assert!(matches!(
        &model.side_rows()[1],
        SideDiffRow::Change {
            left: Some(1),
            right: Some(2)
        }
    ));
}

#[test]
fn empty_patch_becomes_equal_message() {
    let model = DiffModel::from_unified_patch("left".to_owned(), "right".to_owned(), "");

    assert!(!model.has_changes());
    assert_eq!(model.row_count(DiffLayout::Unified), 1);
    assert!(model.changed_rows(DiffLayout::Unified).is_empty());
}

#[test]
fn reads_unified_patch_from_stream() {
    let patch = "\
--- left
+++ right
@@ -1,1 +1,1 @@
-old
+new
";
    let model = DiffModel::from_unified_reader(
        "left".to_owned(),
        "right".to_owned(),
        std::io::Cursor::new(patch),
    )
    .unwrap();

    assert!(model.has_changes());
    assert_eq!(model.row_count(DiffLayout::Unified), 2);
    assert_eq!(model.changed_rows(DiffLayout::SideBySide), &[0]);
}

#[test]
fn large_inline_diff_work_is_budgeted() {
    let mut patch = String::from("--- left\n+++ right\n@@ -1,2050 +1,2050 @@\n");
    for index in 0..2050 {
        patch.push_str(&format!("-old-{index}\n"));
    }
    for index in 0..2050 {
        patch.push_str(&format!("+new-{index}\n"));
    }

    let model = DiffModel::from_unified_patch("left".to_owned(), "right".to_owned(), &patch);
    let row = &model.unified_rows()[INLINE_DIFF_PAIR_BUDGET + 1];

    assert!(matches!(
        row,
        UnifiedDiffRow::Delete {
            change: DiffChange {
                left_range: None,
                right_range: None,
                ..
            },
            ..
        }
    ));
}

#[test]
#[ignore = "performance smoke; run benches/diff-performance.sh"]
fn perf_diff_model_build() {
    let patch = generated_patch(2_048, 3);
    let started = Instant::now();
    let mut rows = 0;
    let mut changes = 0;
    for _ in 0..16 {
        let model = DiffModel::from_unified_patch(
            "left.json".to_owned(),
            "right.json".to_owned(),
            black_box(&patch),
        );
        rows = model.row_count(DiffLayout::Unified);
        changes = model.changed_rows(DiffLayout::Unified).len();
        black_box(model);
    }
    let elapsed = started.elapsed();
    eprintln!(
        "diff model build: {elapsed:?}, rows={rows} changes={changes} patch_bytes={}",
        patch.len()
    );
}

fn generated_patch(hunks: usize, changes_per_hunk: usize) -> String {
    let mut patch = String::from("--- left.json\n+++ right.json\n");
    for hunk in 0..hunks {
        let start = hunk.saturating_mul(16).saturating_add(1);
        patch.push_str(&format!("@@ -{start},10 +{start},10 @@\n"));
        patch.push_str(" {\n");
        patch.push_str(&format!("   \"id\": {hunk},\n"));
        for change in 0..changes_per_hunk {
            patch.push_str(&format!("-  \"old_{change}\": \"{}\",\n", "x".repeat(48)));
        }
        for change in 0..changes_per_hunk {
            patch.push_str(&format!("+  \"new_{change}\": \"{}\",\n", "y".repeat(48)));
        }
        patch.push_str("   \"ok\": true\n");
        patch.push_str(" }\n");
    }
    patch
}