aboutsummaryrefslogtreecommitdiff
path: root/helix-tui/src/backend/test.rs
blob: 4681831d11cabc38124dd0b910a81d4e83942fdc (plain) (blame)
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
use crate::{
    backend::Backend,
    buffer::{Buffer, Cell},
    layout::Rect,
    terminal::CursorKind,
};
use std::{fmt::Write, io};
use unicode_width::UnicodeWidthStr;

/// A backend used for the integration tests.
#[derive(Debug)]
pub struct TestBackend {
    width: u16,
    buffer: Buffer,
    height: u16,
    cursor: bool,
    pos: (u16, u16),
}

/// Returns a string representation of the given buffer for debugging purpose.
fn buffer_view(buffer: &Buffer) -> String {
    let mut view = String::with_capacity(buffer.content.len() + buffer.area.height as usize * 3);
    for cells in buffer.content.chunks(buffer.area.width as usize) {
        let mut overwritten = vec![];
        let mut skip: usize = 0;
        view.push('"');
        for (x, c) in cells.iter().enumerate() {
            if skip == 0 {
                view.push_str(&c.symbol);
            } else {
                overwritten.push((x, &c.symbol))
            }
            skip = std::cmp::max(skip, c.symbol.width()).saturating_sub(1);
        }
        view.push('"');
        if !overwritten.is_empty() {
            write!(
                &mut view,
                " Hidden by multi-width symbols: {:?}",
                overwritten
            )
            .unwrap();
        }
        view.push('\n');
    }
    view
}

impl TestBackend {
    pub fn new(width: u16, height: u16) -> TestBackend {
        TestBackend {
            width,
            height,
            buffer: Buffer::empty(Rect::new(0, 0, width, height)),
            cursor: false,
            pos: (0, 0),
        }
    }

    pub fn buffer(&self) -> &Buffer {
        &self.buffer
    }

    pub fn resize(&mut self, width: u16, height: u16) {
        self.buffer.resize(Rect::new(0, 0, width, height));
        self.width = width;
        self.height = height;
    }

    pub fn assert_buffer(&self, expected: &Buffer) {
        assert_eq!(expected.area, self.buffer.area);
        let diff = expected.diff(&self.buffer);
        if diff.is_empty() {
            return;
        }

        let mut debug_info = String::from("Buffers are not equal");
        debug_info.push('\n');
        debug_info.push_str("Expected:");
        debug_info.push('\n');
        let expected_view = buffer_view(expected);
        debug_info.push_str(&expected_view);
        debug_info.push('\n');
        debug_info.push_str("Got:");
        debug_info.push('\n');
        let view = buffer_view(&self.buffer);
        debug_info.push_str(&view);
        debug_info.push('\n');

        debug_info.push_str("Diff:");
        debug_info.push('\n');
        let nice_diff = diff
            .iter()
            .enumerate()
            .map(|(i, (x, y, cell))| {
                let expected_cell = expected.get(*x, *y);
                format!(
                    "{}: at ({}, {}) expected {:?} got {:?}",
                    i, x, y, expected_cell, cell
                )
            })
            .collect::<Vec<String>>()
            .join("\n");
        debug_info.push_str(&nice_diff);
        panic!("{}", debug_info);
    }
}

impl Backend for TestBackend {
    fn draw<'a, I>(&mut self, content: I) -> Result<(), io::Error>
    where
        I: Iterator<Item = (u16, u16, &'a Cell)>,
    {
        for (x, y, c) in content {
            let cell = self.buffer.get_mut(x, y);
            *cell = c.clone();
        }
        Ok(())
    }

    fn hide_cursor(&mut self) -> Result<(), io::Error> {
        self.cursor = false;
        Ok(())
    }

    fn show_cursor(&mut self, _kind: CursorKind) -> Result<(), io::Error> {
        self.cursor = true;
        Ok(())
    }

    fn get_cursor(&mut self) -> Result<(u16, u16), io::Error> {
        Ok(self.pos)
    }

    fn set_cursor(&mut self, x: u16, y: u16) -> Result<(), io::Error> {
        self.pos = (x, y);
        Ok(())
    }

    fn clear(&mut self) -> Result<(), io::Error> {
        self.buffer.reset();
        Ok(())
    }

    fn size(&self) -> Result<Rect, io::Error> {
        Ok(Rect::new(0, 0, self.width, self.height))
    }

    fn flush(&mut self) -> Result<(), io::Error> {
        Ok(())
    }
}