cranpose-foundation 0.1.112

Modifiers, nodes, and foundation elements for Cranpose
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
134

use cranpose_foundation::text::{TextFieldBuffer, TextRange};

#[test]
fn a_fresh_buffer_has_no_selection_and_no_changes() {
    let buffer = TextFieldBuffer::new("hello");
    assert!(!buffer.has_selection(), "a new buffer selected something");
    assert!(
        !buffer.has_changes(),
        "a buffer nobody edited claimed to be dirty"
    );
    assert_eq!(buffer.selection(), TextRange::cursor(5));
}

#[test]
fn a_buffer_reports_changes_only_after_it_is_edited() {
    let mut buffer = TextFieldBuffer::new("hello");
    buffer.select_all();
    assert!(
        !buffer.has_changes(),
        "selecting is not editing and must not mark the buffer dirty"
    );

    buffer.insert("!");
    assert!(buffer.has_changes(), "an insert left the buffer clean");
}

#[test]
fn deleting_after_the_cursor_removes_the_following_character() {
    let mut buffer = TextFieldBuffer::with_selection("hello", TextRange::cursor(0));
    buffer.delete_after_cursor();
    assert_eq!(buffer.text(), "ello");
    assert_eq!(
        buffer.selection(),
        TextRange::cursor(0),
        "the cursor moved while deleting forward"
    );
}

#[test]
fn deleting_after_the_cursor_at_the_end_does_nothing() {
    let mut buffer = TextFieldBuffer::new("hello");
    buffer.delete_after_cursor();
    assert_eq!(buffer.text(), "hello");
    assert!(
        !buffer.has_changes(),
        "a delete that removed nothing marked the buffer dirty"
    );
}

#[test]
fn deleting_after_the_cursor_removes_a_whole_character_not_a_byte() {
    let mut buffer = TextFieldBuffer::with_selection("éa", TextRange::cursor(0));
    buffer.delete_after_cursor();
    assert_eq!(buffer.text(), "a");
}

#[test]
fn deleting_after_the_cursor_removes_the_selection_when_there_is_one() {
    let mut buffer = TextFieldBuffer::with_selection("hello", TextRange::new(1, 4));
    buffer.delete_after_cursor();
    assert_eq!(buffer.text(), "ho");
    assert!(!buffer.has_selection());
}

#[test]
fn extending_the_selection_left_grows_it_one_character_at_a_time() {
    let mut buffer = TextFieldBuffer::new("hello");
    buffer.extend_selection_left();
    assert_eq!(buffer.selection(), TextRange::new(5, 4));
    buffer.extend_selection_left();
    assert_eq!(buffer.selection(), TextRange::new(5, 3));
    assert_eq!(
        buffer.copy_selection().as_deref(),
        Some("lo"),
        "the extended selection did not cover the characters it grew over"
    );
}

#[test]
fn extending_the_selection_left_stops_at_the_start() {
    let mut buffer = TextFieldBuffer::with_selection("ab", TextRange::cursor(0));
    buffer.extend_selection_left();
    assert_eq!(buffer.selection(), TextRange::cursor(0));
}

#[test]
fn extending_left_and_then_right_returns_to_where_it_began() {
    let mut buffer = TextFieldBuffer::with_selection("hello", TextRange::cursor(2));
    buffer.extend_selection_left();
    assert!(buffer.has_selection());
    buffer.extend_selection_right();
    assert_eq!(
        buffer.selection(),
        TextRange::cursor(2),
        "shift-left then shift-right left a selection behind"
    );

    buffer.extend_selection_right();
    assert!(buffer.has_selection());
    buffer.extend_selection_left();
    assert_eq!(
        buffer.selection(),
        TextRange::cursor(2),
        "shift-right then shift-left left a selection behind"
    );
}

#[test]
fn extending_the_selection_right_grows_it_one_character_at_a_time() {
    let mut buffer = TextFieldBuffer::with_selection("hello", TextRange::cursor(0));
    buffer.extend_selection_right();
    assert_eq!(buffer.selection(), TextRange::new(0, 1));
    buffer.extend_selection_right();
    assert_eq!(buffer.selection(), TextRange::new(0, 2));
    assert_eq!(buffer.copy_selection().as_deref(), Some("he"));
}

#[test]
fn extending_the_selection_right_stops_at_the_end() {
    let mut buffer = TextFieldBuffer::new("ab");
    buffer.extend_selection_right();
    assert_eq!(buffer.selection(), TextRange::cursor(2));
}

#[test]
fn extending_the_selection_walks_whole_characters() {
    let mut buffer = TextFieldBuffer::with_selection("éa", TextRange::cursor(0));
    buffer.extend_selection_right();
    assert_eq!(
        buffer.copy_selection().as_deref(),
        Some("é"),
        "the selection stopped inside a multi-byte character"
    );
}