tui-syntax-highlight 0.2.0

A syntax highlighter for Ratatui apps
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
130
131
132
133

use std::cell::LazyCell;
use std::fs::File;
use std::sync::LazyLock;

use ratatui::Terminal;
use ratatui::backend::TestBackend;
use ratatui::style::Color;
use ratatui::text::Span;
use ratatui::widgets::Widget;
use syntect::highlighting::ThemeSet;
use syntect::parsing::SyntaxSet;
use syntect::util::LinesWithEndings;
use syntect_assets::assets::HighlightingAssets;
use tui_syntax_highlight::Highlighter;

static SYNTAXES: LazyLock<SyntaxSet> = LazyLock::new(SyntaxSet::load_defaults_newlines);
static THEMES: LazyLock<ThemeSet> = LazyLock::new(ThemeSet::load_defaults);
thread_local! {
    static ASSETS: LazyCell<HighlightingAssets> = LazyCell::new(HighlightingAssets::from_binary);
}

macro_rules! assert_snapshot {
    ($name:literal, $harness:expr) => {
        insta::with_settings!({
            snapshot_path => "./snapshots"
        }, {
            insta::assert_debug_snapshot!($name, $harness.buffer());
        });
    };
}

#[test]
fn highlighter() {
    let highlighter = Highlighter::new(THEMES.themes["base16-ocean.dark"].clone());
    let highlight = highlighter
        .highlight_lines(
            LinesWithEndings::from("select a,b,c from table;\nselect b,c,d from table2;"),
            SYNTAXES.find_syntax_by_name("SQL").unwrap(),
            &SYNTAXES,
        )
        .unwrap();
    assert_snapshot!("highlighter", draw(40, 2, highlight));
}

#[test]
fn highlighter_no_line_number() {
    let highlighter =
        Highlighter::new(THEMES.themes["base16-ocean.dark"].clone()).line_numbers(false);
    let highlight = highlighter
        .highlight_lines(
            LinesWithEndings::from("select a,b,c from table;\nselect b,c,d from table2;"),
            SYNTAXES.find_syntax_by_name("SQL").unwrap(),
            &SYNTAXES,
        )
        .unwrap();
    assert_snapshot!("highlighter_no_line_numbers", draw(40, 2, highlight));
}

#[test]
fn highlighter_override_bg() {
    let highlighter = Highlighter::new(THEMES.themes["base16-ocean.dark"].clone())
        .override_background(Color::Reset);
    let highlight = highlighter
        .highlight_lines(
            LinesWithEndings::from("select a,b,c from table;\nselect b,c,d from table2;"),
            SYNTAXES.find_syntax_by_name("SQL").unwrap(),
            &SYNTAXES,
        )
        .unwrap();
    assert_snapshot!("highlighter_override_bg", draw(40, 2, highlight));
}

#[test]
fn highlighter_template() {
    let highlighter =
        Highlighter::new(THEMES.themes["base16-ocean.dark"].clone()).gutter_template(|n, style| {
            vec![
                Span::raw(n.to_string()),
                Span::raw(" "),
                Span::styled(">", style),
            ]
        });
    let highlight = highlighter
        .highlight_lines(
            LinesWithEndings::from("select a,b,c from table;\nselect b,c,d from table2;"),
            SYNTAXES.find_syntax_by_name("SQL").unwrap(),
            &SYNTAXES,
        )
        .unwrap();
    assert_snapshot!("highlighter_template", draw(40, 2, highlight));
}

#[test]
fn highlight_file_ansi() {
    let theme = ASSETS.with(|a| a.get_theme("ansi").clone());
    let syntaxes = ASSETS.with(|a| a.get_syntax_set().unwrap().clone());
    let syntax = syntaxes.find_syntax_by_name("Rust").unwrap();
    let highlighter = Highlighter::new(theme);
    let highlight = highlighter
        .highlight_reader(
            File::open("./tests/assets/test_file.rs").unwrap(),
            syntax,
            &syntaxes,
        )
        .unwrap();
    assert_snapshot!("highlight_file_ansi", draw(40, 3, highlight));
}

#[test]
fn highlight_range() {
    let highlighter =
        Highlighter::new(THEMES.themes["base16-ocean.dark"].clone()).highlight_range(0..1);
    let highlight = highlighter
        .highlight_lines(
            LinesWithEndings::from("select a,b,c from table;\nselect b,c,d from table2;"),
            SYNTAXES.find_syntax_by_name("SQL").unwrap(),
            &SYNTAXES,
        )
        .unwrap();
    assert_snapshot!("highlight_range", draw(40, 2, highlight));
}

fn draw<W>(width: u16, height: u16, widget: W) -> TestBackend
where
    W: Widget,
{
    let backend = TestBackend::new(width, height);
    let mut terminal = Terminal::new(backend).unwrap();
    terminal
        .draw(|f| f.render_widget(widget, f.area()))
        .unwrap();
    terminal.backend().clone()
}