aboutsummaryrefslogtreecommitdiff
path: root/crates/completion/src/completions/fn_param.rs
diff options
context:
space:
mode:
Diffstat (limited to 'crates/completion/src/completions/fn_param.rs')
-rw-r--r--crates/completion/src/completions/fn_param.rs135
1 files changed, 135 insertions, 0 deletions
diff --git a/crates/completion/src/completions/fn_param.rs b/crates/completion/src/completions/fn_param.rs
new file mode 100644
index 000000000..e777a53c1
--- /dev/null
+++ b/crates/completion/src/completions/fn_param.rs
@@ -0,0 +1,135 @@
1//! See `complete_fn_param`.
2
3use rustc_hash::FxHashMap;
4use syntax::{
5 ast::{self, ModuleItemOwner},
6 match_ast, AstNode,
7};
8
9use crate::{CompletionContext, CompletionItem, CompletionKind, Completions};
10
11/// Complete repeated parameters, both name and type. For example, if all
12/// functions in a file have a `spam: &mut Spam` parameter, a completion with
13/// `spam: &mut Spam` insert text/label and `spam` lookup string will be
14/// suggested.
15pub(crate) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext) {
16 if !ctx.is_param {
17 return;
18 }
19
20 let mut params = FxHashMap::default();
21
22 let me = ctx.token.ancestors().find_map(ast::Fn::cast);
23 let mut process_fn = |func: ast::Fn| {
24 if Some(&func) == me.as_ref() {
25 return;
26 }
27 func.param_list().into_iter().flat_map(|it| it.params()).for_each(|param| {
28 let text = param.syntax().text().to_string();
29 params.entry(text).or_insert(param);
30 })
31 };
32
33 for node in ctx.token.parent().ancestors() {
34 match_ast! {
35 match node {
36 ast::SourceFile(it) => it.items().filter_map(|item| match item {
37 ast::Item::Fn(it) => Some(it),
38 _ => None,
39 }).for_each(&mut process_fn),
40 ast::ItemList(it) => it.items().filter_map(|item| match item {
41 ast::Item::Fn(it) => Some(it),
42 _ => None,
43 }).for_each(&mut process_fn),
44 ast::AssocItemList(it) => it.assoc_items().filter_map(|item| match item {
45 ast::AssocItem::Fn(it) => Some(it),
46 _ => None,
47 }).for_each(&mut process_fn),
48 _ => continue,
49 }
50 };
51 }
52
53 params
54 .into_iter()
55 .filter_map(|(label, param)| {
56 let lookup = param.pat()?.syntax().text().to_string();
57 Some((label, lookup))
58 })
59 .for_each(|(label, lookup)| {
60 CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label)
61 .kind(crate::CompletionItemKind::Binding)
62 .lookup_by(lookup)
63 .add_to(acc)
64 });
65}
66
67#[cfg(test)]
68mod tests {
69 use expect_test::{expect, Expect};
70
71 use crate::{test_utils::completion_list, CompletionKind};
72
73 fn check(ra_fixture: &str, expect: Expect) {
74 let actual = completion_list(ra_fixture, CompletionKind::Magic);
75 expect.assert_eq(&actual);
76 }
77
78 #[test]
79 fn test_param_completion_last_param() {
80 check(
81 r#"
82fn foo(file_id: FileId) {}
83fn bar(file_id: FileId) {}
84fn baz(file<|>) {}
85"#,
86 expect![[r#"
87 bn file_id: FileId
88 "#]],
89 );
90 }
91
92 #[test]
93 fn test_param_completion_nth_param() {
94 check(
95 r#"
96fn foo(file_id: FileId) {}
97fn baz(file<|>, x: i32) {}
98"#,
99 expect![[r#"
100 bn file_id: FileId
101 "#]],
102 );
103 }
104
105 #[test]
106 fn test_param_completion_trait_param() {
107 check(
108 r#"
109pub(crate) trait SourceRoot {
110 pub fn contains(&self, file_id: FileId) -> bool;
111 pub fn module_map(&self) -> &ModuleMap;
112 pub fn lines(&self, file_id: FileId) -> &LineIndex;
113 pub fn syntax(&self, file<|>)
114}
115"#,
116 expect![[r#"
117 bn file_id: FileId
118 "#]],
119 );
120 }
121
122 #[test]
123 fn completes_param_in_inner_function() {
124 check(
125 r#"
126fn outer(text: String) {
127 fn inner(<|>)
128}
129"#,
130 expect![[r#"
131 bn text: String
132 "#]],
133 )
134 }
135}