htui 0.2.0

A terminal HTML/CSS renderer with an embedded JavaScript engine — build interactive TUIs from HTML, CSS and JS
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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200

//! Tests for `<em>` (emphasis) inline rendering.
//!
//! `<em>` participates in inline rendering through `walk_runs`. These tests
//! pin down that em text
//! reaches the canvas, the user-agent default (`font-style: italic`) applies
//! when no CSS overrides it, and author CSS overrides take precedence over
//! the default (e.g. `em { font-style: normal }` or `em { color: red }`).
//!
//! The parser-level mapping (`<em>` → `NodeType::Em`) and CSS selector
//! matching (`em { … }`) are covered by the generic tag-selector tests in
//! `html_parse_tests` / `css_parse_tests`; these tests focus on layout-time
//! behavior.

use crossterm::style::Color;
use htui::html::{css_parse, html_parse};
use htui::layout::layout::TermMap;
use htui::tui::graph_api::{FontStyle, TermLayout};

fn init() {
    let _ = env_logger::builder().is_test(true).try_init();
}

fn setup(html: &str, css: &str) -> (htui::tdom::node::NodeId, htui::tdom::node::NodeArena) {
    let mut html_parser = html_parse::Parser::new(html);
    let (root_id, mut arena, embedded) = html_parser.parse();
    let combined = if css.is_empty() {
        embedded
    } else if embedded.is_empty() {
        css.to_string()
    } else {
        format!("{embedded}\n{css}")
    };
    if !combined.trim().is_empty() {
        let mut css_parser = css_parse::Parser::new(&combined);
        let rules = css_parser.parse();
        css_parse::css_into_node(&mut arena, root_id, &rules);
    }
    (root_id, arena)
}

const COLS: u16 = 80;
const ROWS: u16 = 24;

fn mock_term_map() -> TermMap {
    TermMap {
        columns: COLS,
        rows: ROWS,
    }
}

fn canvas_string(tl: &TermLayout) -> String {
    tl.layout.iter().map(|b| b.word.as_str()).collect()
}

fn first_cell_with(tl: &TermLayout, word: &str) -> Option<usize> {
    tl.layout.iter().position(|b| b.word == word)
}

#[test]
fn test_em_renders_text_content() {
    // The emphasised text must reach the canvas. Before this was implemented
    // the text inside `<em>` was silently dropped by `walk_runs` because the
    // parser flattened unknown inline tags.
    init();
    let (root_id, arena) = setup("<p>plain <em>italic</em> tail</p>", "");
    let term_map = mock_term_map();
    let mut tl = TermLayout::new(&term_map, 1.0);
    tl.draw(&arena, root_id, &term_map);
    let canvas = canvas_string(&tl);
    assert!(canvas.contains("plain"), "pre-em text must render");
    assert!(canvas.contains("italic"), "em text must render");
    assert!(canvas.contains("tail"), "post-em text must render");
}

#[test]
fn test_em_default_italic_applies() {
    // UA default: an unstyled `<em>` is italic.
    init();
    let (root_id, arena) = setup("<p><em>word</em></p>", "");
    let term_map = mock_term_map();
    let mut tl = TermLayout::new(&term_map, 1.0);
    tl.draw(&arena, root_id, &term_map);
    let idx = first_cell_with(&tl, "w").expect("em text must render");
    let cell = &tl.layout[idx];
    assert!(
        cell.style.contains(FontStyle::ITALIC),
        "default <em> rendering must be italic (got style {:?})",
        cell.style
    );
}

#[test]
fn test_em_default_italic_does_not_leak_outside_em() {
    // The italic flag must stay scoped to the em's text — surrounding
    // siblings keep the inherited (non-italic) style. Use `f` (only inside
    // em) and `x` (only outside) so the cell lookup is unambiguous.
    init();
    let (root_id, arena) = setup("<p>xxx <em>foo</em> yyy</p>", "");
    let term_map = mock_term_map();
    let mut tl = TermLayout::new(&term_map, 1.0);
    tl.draw(&arena, root_id, &term_map);

    let em_idx = first_cell_with(&tl, "f").expect("em text must render");
    let plain_idx = first_cell_with(&tl, "x").expect("pre-em text must render");
    assert!(tl.layout[em_idx].style.contains(FontStyle::ITALIC));
    assert!(
        !tl.layout[plain_idx].style.contains(FontStyle::ITALIC),
        "text outside <em> must not inherit the UA italic flag (got {:?})",
        tl.layout[plain_idx].style
    );
}

#[test]
fn test_em_font_style_normal_disables_italic() {
    // Author CSS resetting the UA default must take effect.
    init();
    let (root_id, arena) = setup("<p><em>word</em></p>", "em { font-style: normal; }");
    let term_map = mock_term_map();
    let mut tl = TermLayout::new(&term_map, 1.0);
    tl.draw(&arena, root_id, &term_map);
    let idx = first_cell_with(&tl, "w").expect("em text must render");
    let cell = &tl.layout[idx];
    assert!(
        !cell.style.contains(FontStyle::ITALIC),
        "`em {{ font-style: normal }}` must suppress the UA italic default (got {:?})",
        cell.style
    );
}

#[test]
fn test_em_color_override_applies() {
    // A `color` rule on `<em>` must reach the canvas cell while the UA italic
    // default still applies (no `font-style` declared to suppress it).
    init();
    let (root_id, arena) = setup("<p><em>word</em></p>", "em { color: magenta; }");
    let term_map = mock_term_map();
    let mut tl = TermLayout::new(&term_map, 1.0);
    tl.draw(&arena, root_id, &term_map);
    let idx = first_cell_with(&tl, "w").expect("em text must render");
    let cell = &tl.layout[idx];
    assert_eq!(
        cell.fcolor,
        Some(Color::Rgb {
            r: 255,
            g: 0,
            b: 255
        }),
        "`em {{ color: magenta }}` must paint the cell magenta (got {:?})",
        cell.fcolor
    );
    assert!(
        cell.style.contains(FontStyle::ITALIC),
        "color override must not affect the italic UA default"
    );
}

#[test]
fn test_em_nested_in_p_renders_correctly() {
    // Exercise `<em>` inline inside a paragraph among other text. Confirm
    // the em tag survives and its italic flag is applied while the
    // surrounding text is not italic.
    // Use `l` (only in em "inline" and after) and `A` (only in pre-em
    // "Another") to disambiguate which cell we're inspecting.
    init();
    let (root_id, arena) = setup(
        "<p>Another paragraph with <em>inline</em> elements (em tags are flattened).</p>",
        "",
    );
    let term_map = mock_term_map();
    let mut tl = TermLayout::new(&term_map, 1.0);
    tl.draw(&arena, root_id, &term_map);
    let canvas = canvas_string(&tl);
    assert!(
        canvas.contains("inline"),
        "em text must survive in the rendered canvas"
    );

    // The first 'l' in the canvas is inside em ("inline").
    let em_idx = first_cell_with(&tl, "l").expect("em text must render");
    assert!(tl.layout[em_idx].style.contains(FontStyle::ITALIC));
    let another_idx = first_cell_with(&tl, "A").expect("pre-em text must render");
    assert!(!tl.layout[another_idx].style.contains(FontStyle::ITALIC));
}

#[test]
fn test_em_inside_div_paint_layer() {
    // `<em>` is also reachable through the div layout path (different from
    // `<p>`). Confirm the same UA italic default applies.
    init();
    let (root_id, arena) = setup("<div>before <em>italic-here</em> after</div>", "");
    let term_map = mock_term_map();
    let mut tl = TermLayout::new(&term_map, 1.0);
    tl.draw(&arena, root_id, &term_map);
    let idx = first_cell_with(&tl, "i").expect("em text must render");
    assert!(
        tl.layout[idx].style.contains(FontStyle::ITALIC),
        "<em> inside <div> must receive the UA italic default (got {:?})",
        tl.layout[idx].style
    );
}