diff options
Diffstat (limited to 'crates/ra_assists/src/handlers/invert_if.rs')
-rw-r--r-- | crates/ra_assists/src/handlers/invert_if.rs | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/crates/ra_assists/src/handlers/invert_if.rs b/crates/ra_assists/src/handlers/invert_if.rs new file mode 100644 index 000000000..a594e7e0c --- /dev/null +++ b/crates/ra_assists/src/handlers/invert_if.rs | |||
@@ -0,0 +1,91 @@ | |||
1 | use ra_syntax::ast::{self, AstNode}; | ||
2 | use ra_syntax::T; | ||
3 | |||
4 | use crate::{utils::invert_boolean_expression, Assist, AssistCtx, AssistId}; | ||
5 | |||
6 | // Assist: invert_if | ||
7 | // | ||
8 | // Apply invert_if | ||
9 | // This transforms if expressions of the form `if !x {A} else {B}` into `if x {B} else {A}` | ||
10 | // This also works with `!=`. This assist can only be applied with the cursor | ||
11 | // on `if`. | ||
12 | // | ||
13 | // ``` | ||
14 | // fn main() { | ||
15 | // if<|> !y { A } else { B } | ||
16 | // } | ||
17 | // ``` | ||
18 | // -> | ||
19 | // ``` | ||
20 | // fn main() { | ||
21 | // if y { B } else { A } | ||
22 | // } | ||
23 | // ``` | ||
24 | |||
25 | pub(crate) fn invert_if(ctx: AssistCtx) -> Option<Assist> { | ||
26 | let if_keyword = ctx.find_token_at_offset(T![if])?; | ||
27 | let expr = ast::IfExpr::cast(if_keyword.parent())?; | ||
28 | let if_range = if_keyword.text_range(); | ||
29 | let cursor_in_range = ctx.frange.range.is_subrange(&if_range); | ||
30 | if !cursor_in_range { | ||
31 | return None; | ||
32 | } | ||
33 | |||
34 | let cond = expr.condition()?.expr()?; | ||
35 | let then_node = expr.then_branch()?.syntax().clone(); | ||
36 | |||
37 | if let ast::ElseBranch::Block(else_block) = expr.else_branch()? { | ||
38 | let cond_range = cond.syntax().text_range(); | ||
39 | let flip_cond = invert_boolean_expression(cond); | ||
40 | let else_node = else_block.syntax(); | ||
41 | let else_range = else_node.text_range(); | ||
42 | let then_range = then_node.text_range(); | ||
43 | return ctx.add_assist(AssistId("invert_if"), "Invert if", |edit| { | ||
44 | edit.target(if_range); | ||
45 | edit.replace(cond_range, flip_cond.syntax().text()); | ||
46 | edit.replace(else_range, then_node.text()); | ||
47 | edit.replace(then_range, else_node.text()); | ||
48 | }); | ||
49 | } | ||
50 | |||
51 | None | ||
52 | } | ||
53 | |||
54 | #[cfg(test)] | ||
55 | mod tests { | ||
56 | use super::*; | ||
57 | |||
58 | use crate::helpers::{check_assist, check_assist_not_applicable}; | ||
59 | |||
60 | #[test] | ||
61 | fn invert_if_remove_inequality() { | ||
62 | check_assist( | ||
63 | invert_if, | ||
64 | "fn f() { i<|>f x != 3 { 1 } else { 3 + 2 } }", | ||
65 | "fn f() { i<|>f x == 3 { 3 + 2 } else { 1 } }", | ||
66 | ) | ||
67 | } | ||
68 | |||
69 | #[test] | ||
70 | fn invert_if_remove_not() { | ||
71 | check_assist( | ||
72 | invert_if, | ||
73 | "fn f() { <|>if !cond { 3 * 2 } else { 1 } }", | ||
74 | "fn f() { <|>if cond { 1 } else { 3 * 2 } }", | ||
75 | ) | ||
76 | } | ||
77 | |||
78 | #[test] | ||
79 | fn invert_if_general_case() { | ||
80 | check_assist( | ||
81 | invert_if, | ||
82 | "fn f() { i<|>f cond { 3 * 2 } else { 1 } }", | ||
83 | "fn f() { i<|>f !cond { 1 } else { 3 * 2 } }", | ||
84 | ) | ||
85 | } | ||
86 | |||
87 | #[test] | ||
88 | fn invert_if_doesnt_apply_with_cursor_not_on_if() { | ||
89 | check_assist_not_applicable(invert_if, "fn f() { if !<|>cond { 3 * 2 } else { 1 } }") | ||
90 | } | ||
91 | } | ||