diff options
Diffstat (limited to 'crates/ide_diagnostics/src/handlers/missing_ok_or_some_in_tail_expr.rs')
-rw-r--r-- | crates/ide_diagnostics/src/handlers/missing_ok_or_some_in_tail_expr.rs | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/crates/ide_diagnostics/src/handlers/missing_ok_or_some_in_tail_expr.rs b/crates/ide_diagnostics/src/handlers/missing_ok_or_some_in_tail_expr.rs new file mode 100644 index 000000000..c0edcd7d3 --- /dev/null +++ b/crates/ide_diagnostics/src/handlers/missing_ok_or_some_in_tail_expr.rs | |||
@@ -0,0 +1,165 @@ | |||
1 | use hir::db::AstDatabase; | ||
2 | use ide_db::{assists::Assist, source_change::SourceChange}; | ||
3 | use syntax::AstNode; | ||
4 | use text_edit::TextEdit; | ||
5 | |||
6 | use crate::{fix, Diagnostic, DiagnosticsContext}; | ||
7 | |||
8 | // Diagnostic: missing-ok-or-some-in-tail-expr | ||
9 | // | ||
10 | // This diagnostic is triggered if a block that should return `Result` returns a value not wrapped in `Ok`, | ||
11 | // or if a block that should return `Option` returns a value not wrapped in `Some`. | ||
12 | // | ||
13 | // Example: | ||
14 | // | ||
15 | // ```rust | ||
16 | // fn foo() -> Result<u8, ()> { | ||
17 | // 10 | ||
18 | // } | ||
19 | // ``` | ||
20 | pub(crate) fn missing_ok_or_some_in_tail_expr( | ||
21 | ctx: &DiagnosticsContext<'_>, | ||
22 | d: &hir::MissingOkOrSomeInTailExpr, | ||
23 | ) -> Diagnostic { | ||
24 | Diagnostic::new( | ||
25 | "missing-ok-or-some-in-tail-expr", | ||
26 | format!("wrap return expression in {}", d.required), | ||
27 | ctx.sema.diagnostics_display_range(d.expr.clone().map(|it| it.into())).range, | ||
28 | ) | ||
29 | .with_fixes(fixes(ctx, d)) | ||
30 | } | ||
31 | |||
32 | fn fixes(ctx: &DiagnosticsContext<'_>, d: &hir::MissingOkOrSomeInTailExpr) -> Option<Vec<Assist>> { | ||
33 | let root = ctx.sema.db.parse_or_expand(d.expr.file_id)?; | ||
34 | let tail_expr = d.expr.value.to_node(&root); | ||
35 | let tail_expr_range = tail_expr.syntax().text_range(); | ||
36 | let replacement = format!("{}({})", d.required, tail_expr.syntax()); | ||
37 | let edit = TextEdit::replace(tail_expr_range, replacement); | ||
38 | let source_change = | ||
39 | SourceChange::from_text_edit(d.expr.file_id.original_file(ctx.sema.db), edit); | ||
40 | let name = if d.required == "Ok" { "Wrap with Ok" } else { "Wrap with Some" }; | ||
41 | Some(vec![fix("wrap_tail_expr", name, source_change, tail_expr_range)]) | ||
42 | } | ||
43 | |||
44 | #[cfg(test)] | ||
45 | mod tests { | ||
46 | use crate::tests::{check_diagnostics, check_fix}; | ||
47 | |||
48 | #[test] | ||
49 | fn test_wrap_return_type_option() { | ||
50 | check_fix( | ||
51 | r#" | ||
52 | //- minicore: option, result | ||
53 | fn div(x: i32, y: i32) -> Option<i32> { | ||
54 | if y == 0 { | ||
55 | return None; | ||
56 | } | ||
57 | x / y$0 | ||
58 | } | ||
59 | "#, | ||
60 | r#" | ||
61 | fn div(x: i32, y: i32) -> Option<i32> { | ||
62 | if y == 0 { | ||
63 | return None; | ||
64 | } | ||
65 | Some(x / y) | ||
66 | } | ||
67 | "#, | ||
68 | ); | ||
69 | } | ||
70 | |||
71 | #[test] | ||
72 | fn test_wrap_return_type() { | ||
73 | check_fix( | ||
74 | r#" | ||
75 | //- minicore: option, result | ||
76 | fn div(x: i32, y: i32) -> Result<i32, ()> { | ||
77 | if y == 0 { | ||
78 | return Err(()); | ||
79 | } | ||
80 | x / y$0 | ||
81 | } | ||
82 | "#, | ||
83 | r#" | ||
84 | fn div(x: i32, y: i32) -> Result<i32, ()> { | ||
85 | if y == 0 { | ||
86 | return Err(()); | ||
87 | } | ||
88 | Ok(x / y) | ||
89 | } | ||
90 | "#, | ||
91 | ); | ||
92 | } | ||
93 | |||
94 | #[test] | ||
95 | fn test_wrap_return_type_handles_generic_functions() { | ||
96 | check_fix( | ||
97 | r#" | ||
98 | //- minicore: option, result | ||
99 | fn div<T>(x: T) -> Result<T, i32> { | ||
100 | if x == 0 { | ||
101 | return Err(7); | ||
102 | } | ||
103 | $0x | ||
104 | } | ||
105 | "#, | ||
106 | r#" | ||
107 | fn div<T>(x: T) -> Result<T, i32> { | ||
108 | if x == 0 { | ||
109 | return Err(7); | ||
110 | } | ||
111 | Ok(x) | ||
112 | } | ||
113 | "#, | ||
114 | ); | ||
115 | } | ||
116 | |||
117 | #[test] | ||
118 | fn test_wrap_return_type_handles_type_aliases() { | ||
119 | check_fix( | ||
120 | r#" | ||
121 | //- minicore: option, result | ||
122 | type MyResult<T> = Result<T, ()>; | ||
123 | |||
124 | fn div(x: i32, y: i32) -> MyResult<i32> { | ||
125 | if y == 0 { | ||
126 | return Err(()); | ||
127 | } | ||
128 | x $0/ y | ||
129 | } | ||
130 | "#, | ||
131 | r#" | ||
132 | type MyResult<T> = Result<T, ()>; | ||
133 | |||
134 | fn div(x: i32, y: i32) -> MyResult<i32> { | ||
135 | if y == 0 { | ||
136 | return Err(()); | ||
137 | } | ||
138 | Ok(x / y) | ||
139 | } | ||
140 | "#, | ||
141 | ); | ||
142 | } | ||
143 | |||
144 | #[test] | ||
145 | fn test_wrap_return_type_not_applicable_when_expr_type_does_not_match_ok_type() { | ||
146 | check_diagnostics( | ||
147 | r#" | ||
148 | //- minicore: option, result | ||
149 | fn foo() -> Result<(), i32> { 0 } | ||
150 | "#, | ||
151 | ); | ||
152 | } | ||
153 | |||
154 | #[test] | ||
155 | fn test_wrap_return_type_not_applicable_when_return_type_is_not_result_or_option() { | ||
156 | check_diagnostics( | ||
157 | r#" | ||
158 | //- minicore: option, result | ||
159 | enum SomeOtherEnum { Ok(i32), Err(String) } | ||
160 | |||
161 | fn foo() -> SomeOtherEnum { 0 } | ||
162 | "#, | ||
163 | ); | ||
164 | } | ||
165 | } | ||