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authorAkshay <[email protected]>2021-09-21 12:11:24 +0100
committerAkshay <[email protected]>2021-09-21 12:11:24 +0100
commit40867728c023a9f95f346671b51be68002cc7552 (patch)
treee856327b0d42d9a4740c460a5efb633f8a73f3d9 /lib/src/lints
parentc91c2ae1398e4f567ee5e4c50a1da35a9b65919b (diff)
add suggestion to bool_comparison
Diffstat (limited to 'lib/src/lints')
-rw-r--r--lib/src/lints/bool_comparison.rs88
1 files changed, 54 insertions, 34 deletions
diff --git a/lib/src/lints/bool_comparison.rs b/lib/src/lints/bool_comparison.rs
index 918126f..f869e17 100644
--- a/lib/src/lints/bool_comparison.rs
+++ b/lib/src/lints/bool_comparison.rs
@@ -1,4 +1,4 @@
1use crate::{Lint, Metadata, Report, Rule}; 1use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
2 2
3use if_chain::if_chain; 3use if_chain::if_chain;
4use macros::lint; 4use macros::lint;
@@ -22,22 +22,58 @@ impl Rule for BoolComparison {
22 if let Some(lhs) = bin_expr.lhs(); 22 if let Some(lhs) = bin_expr.lhs();
23 if let Some(rhs) = bin_expr.rhs(); 23 if let Some(rhs) = bin_expr.rhs();
24 24
25 if let BinOpKind::Equal | BinOpKind::NotEqual = bin_expr.operator(); 25 if let op@(BinOpKind::Equal | BinOpKind::NotEqual) = bin_expr.operator();
26 let (non_bool_side, bool_side) = if is_boolean_ident(&lhs) { 26 let (non_bool_side, bool_side) = if boolean_ident(&lhs).is_some() {
27 (rhs, lhs) 27 (rhs, lhs)
28 } else if is_boolean_ident(&rhs) { 28 } else if boolean_ident(&rhs).is_some() {
29 (lhs, rhs) 29 (lhs, rhs)
30 } else { 30 } else {
31 return None 31 return None
32 }; 32 };
33 then { 33 then {
34 let at = node.text_range(); 34 let at = node.text_range();
35 let replacement = {
36 match (boolean_ident(&bool_side).unwrap(), op == BinOpKind::Equal) {
37 (NixBoolean::True, true) | (NixBoolean::False, false) => {
38 // `a == true`, `a != false` replace with just `a`
39 non_bool_side.clone()
40 },
41 (NixBoolean::True, false) | (NixBoolean::False, true) => {
42 // `a != true`, `a == false` replace with `!a`
43 match non_bool_side.kind() {
44 SyntaxKind::NODE_APPLY
45 | SyntaxKind::NODE_PAREN
46 | SyntaxKind::NODE_IDENT => {
47 // do not parenthsize the replacement
48 make::unary_not(&non_bool_side).node().clone()
49 },
50 SyntaxKind::NODE_BIN_OP => {
51 let inner = BinOp::cast(non_bool_side.clone()).unwrap();
52 // `!a ? b`, no paren required
53 if inner.operator() == BinOpKind::IsSet {
54 make::unary_not(&non_bool_side).node().clone()
55 } else {
56 let parens = make::parenthesize(&non_bool_side);
57 make::unary_not(parens.node()).node().clone()
58 }
59 },
60 _ => {
61 let parens = make::parenthesize(&non_bool_side);
62 make::unary_not(parens.node()).node().clone()
63 }
64 }
65 },
66 }
67 };
35 let message = format!( 68 let message = format!(
36 "Comparing `{}` with boolean literal `{}`", 69 "Comparing `{}` with boolean literal `{}`",
37 non_bool_side, 70 non_bool_side,
38 bool_side 71 bool_side
39 ); 72 );
40 Some(Report::new().diagnostic(at, message)) 73 Some(
74 Report::new(Self::note())
75 .suggest(at, message, Suggestion::new(at, replacement))
76 )
41 } else { 77 } else {
42 None 78 None
43 } 79 }
@@ -45,34 +81,18 @@ impl Rule for BoolComparison {
45 } 81 }
46} 82}
47 83
48// not entirely accurate, underhanded nix programmers might write `true = false` 84enum NixBoolean {
49fn is_boolean_ident(node: &SyntaxNode) -> bool { 85 True,
50 if let Some(ident_expr) = Ident::cast(node.clone()) { 86 False,
51 ident_expr.as_str() == "true" || ident_expr.as_str() == "false"
52 } else {
53 false
54 }
55} 87}
56 88
57// #[cfg(test)] 89// not entirely accurate, underhanded nix programmers might write `true = false`
58// mod tests { 90fn boolean_ident(node: &SyntaxNode) -> Option<NixBoolean> {
59// use super::*; 91 Ident::cast(node.clone())
60// use rnix::{parser, WalkEvent}; 92 .map(|ident_expr| match ident_expr.as_str() {
61// 93 "true" => Some(NixBoolean::True),
62// #[test] 94 "false" => Some(NixBoolean::False),
63// fn trivial() { 95 _ => None,
64// let src = r#" 96 })
65// a == true 97 .flatten()
66// "#; 98}
67// let parsed = rnix::parse(src).as_result().ok().unwrap();
68// let _ = parsed
69// .node()
70// .preorder_with_tokens()
71// .filter_map(|event| match event {
72// WalkEvent::Enter(t) => Some(t),
73// _ => None,
74// })
75// .map(|node| BoolComparison.validate(&node))
76// .collect::<Vec<_>>();
77// }
78// }