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
|
use std::iter::successors;
use ra_syntax::{
algo::neighbor,
ast::{self, edit::AstNodeEdit, make},
AstNode, AstToken, Direction, InsertPosition, SyntaxElement, TextRange, T,
};
use crate::{Assist, AssistCtx, AssistId};
// Assist: merge_imports
//
// Merges two imports with a common prefix.
//
// ```
// use std::<|>fmt::Formatter;
// use std::io;
// ```
// ->
// ```
// use std::{fmt::Formatter, io};
// ```
pub(crate) fn merge_imports(ctx: AssistCtx) -> Option<Assist> {
let tree: ast::UseTree = ctx.find_node_at_offset()?;
let (new_tree, to_delete) = if let Some(use_item) =
tree.syntax().parent().and_then(ast::UseItem::cast)
{
let (merged, to_delete) = next_prev()
.filter_map(|dir| neighbor(&use_item, dir))
.filter_map(|it| Some((it.clone(), it.use_tree()?)))
.find_map(|(use_item, use_tree)| {
Some((try_merge_trees(&tree, &use_tree)?, use_item.clone()))
})?;
let mut range = to_delete.syntax().text_range();
let next_ws = to_delete
.syntax()
.next_sibling_or_token()
.and_then(|it| it.into_token())
.and_then(ast::Whitespace::cast);
if let Some(ws) = next_ws {
range = range.extend_to(&ws.syntax().text_range())
}
(merged, range)
} else {
let (merged, to_delete) = next_prev()
.filter_map(|dir| neighbor(&tree, dir))
.find_map(|use_tree| Some((try_merge_trees(&tree, &use_tree)?, use_tree.clone())))?;
let mut range = to_delete.syntax().text_range();
if let Some((dir, nb)) = next_prev().find_map(|dir| Some((dir, neighbor(&to_delete, dir)?)))
{
let nb_range = nb.syntax().text_range();
if dir == Direction::Prev {
range = TextRange::from_to(nb_range.end(), range.end());
} else {
range = TextRange::from_to(range.start(), nb_range.start());
}
}
(merged, range)
};
let mut offset = ctx.frange.range.start();
ctx.add_assist(AssistId("merge_imports"), "Merge imports", |edit| {
edit.replace_ast(tree, new_tree);
edit.delete(to_delete);
if to_delete.end() <= offset {
offset -= to_delete.len();
}
edit.set_cursor(offset);
})
}
fn next_prev() -> impl Iterator<Item = Direction> {
[Direction::Next, Direction::Prev].iter().copied()
}
fn try_merge_trees(old: &ast::UseTree, new: &ast::UseTree) -> Option<ast::UseTree> {
let lhs_path = old.path()?;
let rhs_path = new.path()?;
let (lhs_prefix, rhs_prefix) = common_prefix(&lhs_path, &rhs_path)?;
let lhs = old.split_prefix(&lhs_prefix);
let rhs = new.split_prefix(&rhs_prefix);
let mut to_insert: Vec<SyntaxElement> = Vec::new();
to_insert.push(make::token(T![,]).into());
to_insert.push(make::tokens::single_space().into());
to_insert.extend(
rhs.use_tree_list()?
.syntax()
.children_with_tokens()
.filter(|it| it.kind() != T!['{'] && it.kind() != T!['}']),
);
let use_tree_list = lhs.use_tree_list()?;
let pos = InsertPosition::Before(use_tree_list.r_curly()?.into());
let use_tree_list = use_tree_list.insert_children(pos, to_insert);
Some(lhs.with_use_tree_list(use_tree_list))
}
fn common_prefix(lhs: &ast::Path, rhs: &ast::Path) -> Option<(ast::Path, ast::Path)> {
let mut res = None;
let mut lhs_curr = first_path(&lhs);
let mut rhs_curr = first_path(&rhs);
loop {
match (lhs_curr.segment(), rhs_curr.segment()) {
(Some(lhs), Some(rhs)) if lhs.syntax().text() == rhs.syntax().text() => (),
_ => break,
}
res = Some((lhs_curr.clone(), rhs_curr.clone()));
match (lhs_curr.parent_path(), rhs_curr.parent_path()) {
(Some(lhs), Some(rhs)) => {
lhs_curr = lhs;
rhs_curr = rhs;
}
_ => break,
}
}
res
}
fn first_path(path: &ast::Path) -> ast::Path {
successors(Some(path.clone()), |it| it.qualifier()).last().unwrap()
}
#[cfg(test)]
mod tests {
use crate::helpers::check_assist;
use super::*;
#[test]
fn test_merge_first() {
check_assist(
merge_imports,
r"
use std::fmt<|>::Debug;
use std::fmt::Display;
",
r"
use std::fmt<|>::{Debug, Display};
",
)
}
#[test]
fn test_merge_second() {
check_assist(
merge_imports,
r"
use std::fmt::Debug;
use std::fmt<|>::Display;
",
r"
use std::fmt<|>::{Display, Debug};
",
);
}
#[test]
fn test_merge_nested() {
check_assist(
merge_imports,
r"
use std::{fmt<|>::Debug, fmt::Display};
",
r"
use std::{fmt<|>::{Debug, Display}};
",
);
check_assist(
merge_imports,
r"
use std::{fmt::Debug, fmt<|>::Display};
",
r"
use std::{fmt<|>::{Display, Debug}};
",
);
}
}
|
