aboutsummaryrefslogtreecommitdiff
path: root/crates/ide_completion/src/completions/attribute/derive.rs
blob: 0bc3eab988b3be68b13dd0b82f915e4f38d700f3 (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
//! Completion for derives
use itertools::Itertools;
use rustc_hash::FxHashSet;
use syntax::ast;

use crate::{
    context::CompletionContext,
    item::{CompletionItem, CompletionItemKind, CompletionKind},
    Completions,
};

pub(super) fn complete_derive(
    acc: &mut Completions,
    ctx: &CompletionContext,
    derive_input: ast::TokenTree,
) {
    if let Some(existing_derives) = super::parse_comma_sep_input(derive_input) {
        for derive_completion in DEFAULT_DERIVE_COMPLETIONS
            .iter()
            .filter(|completion| !existing_derives.contains(completion.label))
        {
            let mut components = vec![derive_completion.label];
            components.extend(
                derive_completion
                    .dependencies
                    .iter()
                    .filter(|&&dependency| !existing_derives.contains(dependency)),
            );
            let lookup = components.join(", ");
            let label = components.iter().rev().join(", ");
            let mut item =
                CompletionItem::new(CompletionKind::Attribute, ctx.source_range(), label);
            item.lookup_by(lookup).kind(CompletionItemKind::Attribute);
            item.add_to(acc);
        }

        for custom_derive_name in get_derive_names_in_scope(ctx).difference(&existing_derives) {
            let mut item = CompletionItem::new(
                CompletionKind::Attribute,
                ctx.source_range(),
                custom_derive_name,
            );
            item.kind(CompletionItemKind::Attribute);
            item.add_to(acc);
        }
    }
}

fn get_derive_names_in_scope(ctx: &CompletionContext) -> FxHashSet<String> {
    let mut result = FxHashSet::default();
    ctx.scope.process_all_names(&mut |name, scope_def| {
        if let hir::ScopeDef::MacroDef(mac) = scope_def {
            if mac.kind() == hir::MacroKind::Derive {
                result.insert(name.to_string());
            }
        }
    });
    result
}

struct DeriveCompletion {
    label: &'static str,
    dependencies: &'static [&'static str],
}

/// Standard Rust derives and the information about their dependencies
/// (the dependencies are needed so that the main derive don't break the compilation when added)
const DEFAULT_DERIVE_COMPLETIONS: &[DeriveCompletion] = &[
    DeriveCompletion { label: "Clone", dependencies: &[] },
    DeriveCompletion { label: "Copy", dependencies: &["Clone"] },
    DeriveCompletion { label: "Debug", dependencies: &[] },
    DeriveCompletion { label: "Default", dependencies: &[] },
    DeriveCompletion { label: "Hash", dependencies: &[] },
    DeriveCompletion { label: "PartialEq", dependencies: &[] },
    DeriveCompletion { label: "Eq", dependencies: &["PartialEq"] },
    DeriveCompletion { label: "PartialOrd", dependencies: &["PartialEq"] },
    DeriveCompletion { label: "Ord", dependencies: &["PartialOrd", "Eq", "PartialEq"] },
];

#[cfg(test)]
mod tests {
    use expect_test::{expect, Expect};

    use crate::{test_utils::completion_list, CompletionKind};

    fn check(ra_fixture: &str, expect: Expect) {
        let actual = completion_list(ra_fixture, CompletionKind::Attribute);
        expect.assert_eq(&actual);
    }

    #[test]
    fn no_completion_for_incorrect_derive() {
        check(r#"#[derive{$0)] struct Test;"#, expect![[]])
    }

    #[test]
    fn empty_derive() {
        check(
            r#"#[derive($0)] struct Test;"#,
            expect![[r#"
                at Clone
                at Clone, Copy
                at Debug
                at Default
                at Hash
                at PartialEq
                at PartialEq, Eq
                at PartialEq, PartialOrd
                at PartialEq, Eq, PartialOrd, Ord
            "#]],
        );
    }

    #[test]
    fn derive_with_input() {
        check(
            r#"#[derive(serde::Serialize, PartialEq, $0)] struct Test;"#,
            expect![[r#"
                at Clone
                at Clone, Copy
                at Debug
                at Default
                at Hash
                at Eq
                at PartialOrd
                at Eq, PartialOrd, Ord
            "#]],
        )
    }

    #[test]
    fn derive_with_input2() {
        check(
            r#"#[derive($0 serde::Serialize, PartialEq)] struct Test;"#,
            expect![[r#"
                at Clone
                at Clone, Copy
                at Debug
                at Default
                at Hash
                at Eq
                at PartialOrd
                at Eq, PartialOrd, Ord
            "#]],
        )
    }
}