diff options
Diffstat (limited to 'crates/ra_assists/src/flip_binexpr.rs')
-rw-r--r-- | crates/ra_assists/src/flip_binexpr.rs | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/crates/ra_assists/src/flip_binexpr.rs b/crates/ra_assists/src/flip_binexpr.rs new file mode 100644 index 000000000..8a0737b55 --- /dev/null +++ b/crates/ra_assists/src/flip_binexpr.rs | |||
@@ -0,0 +1,149 @@ | |||
1 | use hir::db::HirDatabase; | ||
2 | use ra_syntax::ast::{AstNode, BinExpr, BinOp}; | ||
3 | |||
4 | use crate::{AssistCtx, Assist, AssistId}; | ||
5 | |||
6 | /// Flip binary comparison expressions (==, !=, >, >=, <, <=). | ||
7 | pub(crate) fn flip_binexpr(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> { | ||
8 | let expr = ctx.node_at_offset::<BinExpr>()?; | ||
9 | let lhs = expr.lhs()?.syntax(); | ||
10 | let rhs = expr.rhs()?.syntax(); | ||
11 | let op_range = expr.op()?.range(); | ||
12 | // The assist should be available only if the cursor is on the operator | ||
13 | let cursor_in_range = ctx.frange.range.is_subrange(&op_range); | ||
14 | // The assist should be available only for these binary operators | ||
15 | // (it should not change the meaning of the expression) | ||
16 | let allowed_ops = [ | ||
17 | BinOp::EqualityTest, | ||
18 | BinOp::NegatedEqualityTest, | ||
19 | BinOp::GreaterTest, | ||
20 | BinOp::GreaterEqualTest, | ||
21 | BinOp::LesserTest, | ||
22 | BinOp::LesserEqualTest, | ||
23 | ]; | ||
24 | let op_kind = expr.op_kind()?; | ||
25 | if !cursor_in_range || !allowed_ops.iter().any(|o| *o == op_kind) { | ||
26 | return None; | ||
27 | } | ||
28 | let new_op = match op_kind { | ||
29 | BinOp::GreaterTest => Some("<"), | ||
30 | BinOp::GreaterEqualTest => Some("<="), | ||
31 | BinOp::LesserTest => Some(">"), | ||
32 | BinOp::LesserEqualTest => Some(">="), | ||
33 | _ => None, | ||
34 | }; | ||
35 | ctx.add_action(AssistId("flip_binexpr"), "flip binary expression", |edit| { | ||
36 | edit.target(op_range); | ||
37 | if let Some(new_op) = new_op { | ||
38 | edit.replace(op_range, new_op); | ||
39 | } | ||
40 | edit.replace(lhs.range(), rhs.text()); | ||
41 | edit.replace(rhs.range(), lhs.text()); | ||
42 | }); | ||
43 | |||
44 | ctx.build() | ||
45 | } | ||
46 | |||
47 | #[cfg(test)] | ||
48 | mod tests { | ||
49 | use super::*; | ||
50 | |||
51 | use crate::helpers::{check_assist, check_assist_target}; | ||
52 | |||
53 | #[test] | ||
54 | fn flip_eq_operands_for_simple_stmt() { | ||
55 | check_assist( | ||
56 | flip_binexpr, | ||
57 | "fn f() { let res = 1 ==<|> 2; }", | ||
58 | "fn f() { let res = 2 ==<|> 1; }", | ||
59 | ) | ||
60 | } | ||
61 | |||
62 | #[test] | ||
63 | fn flip_neq_operands_for_simple_stmt() { | ||
64 | check_assist( | ||
65 | flip_binexpr, | ||
66 | "fn f() { let res = 1 !=<|> 2; }", | ||
67 | "fn f() { let res = 2 !=<|> 1; }", | ||
68 | ) | ||
69 | } | ||
70 | |||
71 | #[test] | ||
72 | fn flip_gt_operands_for_simple_stmt() { | ||
73 | check_assist( | ||
74 | flip_binexpr, | ||
75 | "fn f() { let res = 1 ><|> 2; }", | ||
76 | "fn f() { let res = 2 <<|> 1; }", | ||
77 | ) | ||
78 | } | ||
79 | |||
80 | #[test] | ||
81 | fn flip_gteq_operands_for_simple_stmt() { | ||
82 | check_assist( | ||
83 | flip_binexpr, | ||
84 | "fn f() { let res = 1 >=<|> 2; }", | ||
85 | "fn f() { let res = 2 <=<|> 1; }", | ||
86 | ) | ||
87 | } | ||
88 | |||
89 | #[test] | ||
90 | fn flip_lt_operands_for_simple_stmt() { | ||
91 | check_assist( | ||
92 | flip_binexpr, | ||
93 | "fn f() { let res = 1 <<|> 2; }", | ||
94 | "fn f() { let res = 2 ><|> 1; }", | ||
95 | ) | ||
96 | } | ||
97 | |||
98 | #[test] | ||
99 | fn flip_lteq_operands_for_simple_stmt() { | ||
100 | check_assist( | ||
101 | flip_binexpr, | ||
102 | "fn f() { let res = 1 <=<|> 2; }", | ||
103 | "fn f() { let res = 2 >=<|> 1; }", | ||
104 | ) | ||
105 | } | ||
106 | |||
107 | #[test] | ||
108 | fn flip_eq_operands_for_complex_stmt() { | ||
109 | check_assist( | ||
110 | flip_binexpr, | ||
111 | "fn f() { let res = (1 + 1) ==<|> (2 + 2); }", | ||
112 | "fn f() { let res = (2 + 2) ==<|> (1 + 1); }", | ||
113 | ) | ||
114 | } | ||
115 | |||
116 | #[test] | ||
117 | fn flip_eq_operands_in_match_expr() { | ||
118 | check_assist( | ||
119 | flip_binexpr, | ||
120 | r#" | ||
121 | fn dyn_eq(&self, other: &dyn Diagnostic) -> bool { | ||
122 | match other.downcast_ref::<Self>() { | ||
123 | None => false, | ||
124 | Some(it) => it ==<|> self, | ||
125 | } | ||
126 | } | ||
127 | "#, | ||
128 | r#" | ||
129 | fn dyn_eq(&self, other: &dyn Diagnostic) -> bool { | ||
130 | match other.downcast_ref::<Self>() { | ||
131 | None => false, | ||
132 | Some(it) => self ==<|> it, | ||
133 | } | ||
134 | } | ||
135 | "#, | ||
136 | ) | ||
137 | } | ||
138 | |||
139 | #[test] | ||
140 | fn flip_eq_operands_target() { | ||
141 | check_assist_target(flip_binexpr, "fn f() { let res = 1 ==<|> 2; }", "==") | ||
142 | } | ||
143 | |||
144 | #[test] | ||
145 | fn flip_gt_operands_target() { | ||
146 | check_assist_target(flip_binexpr, "fn f() { let res = 1 ><|> 2; }", ">") | ||
147 | } | ||
148 | |||
149 | } | ||