rust-analyzer - Unnamed repository; edit this file 'description' to name the repository.


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

use ide_db::{base_db::FileId, source_change::SourceChange};
use itertools::Itertools;
use syntax::{ast, AstNode, SyntaxNode};
use text_edit::TextEdit;

use crate::{fix, Diagnostic, DiagnosticCode};

// Diagnostic: unnecessary-braces
//
// Diagnostic for unnecessary braces in `use` items.
pub(crate) fn useless_braces(
    acc: &mut Vec<Diagnostic>,
    file_id: FileId,
    node: &SyntaxNode,
) -> Option<()> {
    let use_tree_list = ast::UseTreeList::cast(node.clone())?;
    if let Some((single_use_tree,)) = use_tree_list.use_trees().collect_tuple() {
        // If there is a `self` inside the bracketed `use`, don't show diagnostic.
        if single_use_tree.path()?.segment()?.self_token().is_some() {
            return Some(());
        }

        // If there is a comment inside the bracketed `use`,
        // assume it is a commented out module path and don't show diagnostic.
        if use_tree_list.has_inner_comment() {
            return Some(());
        }

        let use_range = use_tree_list.syntax().text_range();
        let to_replace = single_use_tree.syntax().text().to_string();
        let mut edit_builder = TextEdit::builder();
        edit_builder.delete(use_range);
        edit_builder.insert(use_range.start(), to_replace);
        let edit = edit_builder.finish();

        acc.push(
            Diagnostic::new(
                DiagnosticCode::RustcLint("unused_braces"),
                "Unnecessary braces in use statement".to_string(),
                use_range,
            )
            .with_fixes(Some(vec![fix(
                "remove_braces",
                "Remove unnecessary braces",
                SourceChange::from_text_edit(file_id, edit),
                use_range,
            )])),
        );
    }

    Some(())
}

#[cfg(test)]
mod tests {
    use crate::{
        tests::{check_diagnostics, check_diagnostics_with_config, check_fix},
        DiagnosticsConfig,
    };

    #[test]
    fn test_check_unnecessary_braces_in_use_statement() {
        check_diagnostics(
            r#"
use a;
use a::{c, d::e};

mod a {
    pub mod c {}
    pub mod d {
        pub mod e {}
    }
}
"#,
        );
        check_diagnostics(
            r#"
use a;
use a::{
    c,
    // d::e
};

mod a {
    pub mod c {}
    pub mod d {
        pub mod e {}
    }
}
"#,
        );
        check_diagnostics(
            r#"
use a::{self};

mod a {
}
"#,
        );
        check_diagnostics(
            r#"
use a::{self as cool_name};

mod a {
}
"#,
        );

        let mut config = DiagnosticsConfig::test_sample();
        config.disabled.insert("syntax-error".to_string());
        check_diagnostics_with_config(
            config,
            r#"
mod a { pub mod b {} }
use a::{b::self};
"#,
        );
        check_fix(
            r#"
mod b {}
use {$0b};
"#,
            r#"
mod b {}
use b;
"#,
        );
        check_fix(
            r#"
mod b {}
use {b$0};
"#,
            r#"
mod b {}
use b;
"#,
        );
        check_fix(
            r#"
mod a { pub mod c {} }
use a::{c$0};
"#,
            r#"
mod a { pub mod c {} }
use a::c;
"#,
        );
        check_fix(
            r#"
mod a { pub mod c {} pub mod d { pub mod e {} } }
use a::{c, d::{e$0}};
"#,
            r#"
mod a { pub mod c {} pub mod d { pub mod e {} } }
use a::{c, d::e};
"#,
        );
    }
}