aboutsummaryrefslogtreecommitdiff
path: root/crates/ra_assists/src/lib.rs
blob: 555af51bce09b28e6dcd1b526f1df353b0c0be4e (plain)
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
//! `ra_assits` crate provides a bunch of code assists, aslo known as code
//! actions (in LSP) or intentions (in IntelliJ).
//!
//! An assist is a micro-refactoring, which is automatically activated in
//! certain context. For example, if the cursor is over `,`, a "swap `,`" assist
//! becomes available.

mod assist_ctx;

use ra_text_edit::TextEdit;
use ra_syntax::{TextUnit, SyntaxNode, Direction};
use ra_db::FileRange;
use hir::db::HirDatabase;

pub(crate) use crate::assist_ctx::{AssistCtx, Assist};

#[derive(Debug)]
pub struct AssistLabel {
    /// Short description of the assist, as shown in the UI.
    pub label: String,
}

pub struct AssistAction {
    pub edit: TextEdit,
    pub cursor_position: Option<TextUnit>,
}

/// Return all the assists applicable at the given position.
///
/// Assists are returned in the "unresolved" state, that is only labels are
/// returned, without actual edits.
pub fn applicable_assists<H>(db: &H, range: FileRange) -> Vec<AssistLabel>
where
    H: HirDatabase + 'static,
{
    AssistCtx::with_ctx(db, range, false, |ctx| {
        all_assists()
            .iter()
            .filter_map(|f| f(ctx.clone()))
            .map(|a| match a {
                Assist::Unresolved(label) => label,
                Assist::Resolved(..) => unreachable!(),
            })
            .collect()
    })
}

/// Return all the assists applicable at the given position.
///
/// Assists are returned in the "resolved" state, that is with edit fully
/// computed.
pub fn assists<H>(db: &H, range: FileRange) -> Vec<(AssistLabel, AssistAction)>
where
    H: HirDatabase + 'static,
{
    AssistCtx::with_ctx(db, range, true, |ctx| {
        all_assists()
            .iter()
            .filter_map(|f| f(ctx.clone()))
            .map(|a| match a {
                Assist::Resolved(label, action) => (label, action),
                Assist::Unresolved(..) => unreachable!(),
            })
            .collect()
    })
}

mod add_derive;
mod add_impl;
mod flip_comma;
mod change_visibility;
mod fill_match_arms;
mod introduce_variable;
mod replace_if_let_with_match;
mod split_import;
mod remove_dbg;
fn all_assists<DB: HirDatabase>() -> &'static [fn(AssistCtx<DB>) -> Option<Assist>] {
    &[
        add_derive::add_derive,
        add_impl::add_impl,
        change_visibility::change_visibility,
        fill_match_arms::fill_match_arms,
        flip_comma::flip_comma,
        introduce_variable::introduce_variable,
        replace_if_let_with_match::replace_if_let_with_match,
        split_import::split_import,
        remove_dbg::remove_dbg,
    ]
}

fn non_trivia_sibling(node: &SyntaxNode, direction: Direction) -> Option<&SyntaxNode> {
    node.siblings(direction)
        .skip(1)
        .find(|node| !node.kind().is_trivia())
}

#[cfg(test)]
mod helpers {
    use hir::mock::MockDatabase;
    use ra_syntax::TextRange;
    use ra_db::FileRange;
    use test_utils::{extract_offset, assert_eq_text, add_cursor, extract_range};

    use crate::{AssistCtx, Assist};

    pub(crate) fn check_assist(
        assist: fn(AssistCtx<MockDatabase>) -> Option<Assist>,
        before: &str,
        after: &str,
    ) {
        let (before_cursor_pos, before) = extract_offset(before);
        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
        let frange = FileRange {
            file_id,
            range: TextRange::offset_len(before_cursor_pos, 0.into()),
        };
        let assist =
            AssistCtx::with_ctx(&db, frange, true, assist).expect("code action is not applicable");
        let action = match assist {
            Assist::Unresolved(_) => unreachable!(),
            Assist::Resolved(_, it) => it,
        };

        let actual = action.edit.apply(&before);
        let actual_cursor_pos = match action.cursor_position {
            None => action
                .edit
                .apply_to_offset(before_cursor_pos)
                .expect("cursor position is affected by the edit"),
            Some(off) => off,
        };
        let actual = add_cursor(&actual, actual_cursor_pos);
        assert_eq_text!(after, &actual);
    }

    pub(crate) fn check_assist_range(
        assist: fn(AssistCtx<MockDatabase>) -> Option<Assist>,
        before: &str,
        after: &str,
    ) {
        let (range, before) = extract_range(before);
        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
        let frange = FileRange { file_id, range };
        let assist =
            AssistCtx::with_ctx(&db, frange, true, assist).expect("code action is not applicable");
        let action = match assist {
            Assist::Unresolved(_) => unreachable!(),
            Assist::Resolved(_, it) => it,
        };

        let mut actual = action.edit.apply(&before);
        if let Some(pos) = action.cursor_position {
            actual = add_cursor(&actual, pos);
        }
        assert_eq_text!(after, &actual);
    }

    pub(crate) fn check_assist_not_applicable(
        assist: fn(AssistCtx<MockDatabase>) -> Option<Assist>,
        before: &str,
    ) {
        let (before_cursor_pos, before) = extract_offset(before);
        let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
        let frange = FileRange {
            file_id,
            range: TextRange::offset_len(before_cursor_pos, 0.into()),
        };
        let assist = AssistCtx::with_ctx(&db, frange, true, assist);
        assert!(assist.is_none());
    }

}