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use crate::{Lint, Metadata, Report, Rule, Suggestion};
use if_chain::if_chain;
use macros::lint;
use rnix::{
types::{LetIn, TypedNode, EntryHolder},
NodeOrToken, SyntaxElement, SyntaxKind,
};
#[lint(
name = "empty let-in",
note = "Useless let-in expression",
code = 2,
match_with = SyntaxKind::NODE_LET_IN
)]
struct EmptyLetIn;
impl Rule for EmptyLetIn {
fn validate(&self, node: &SyntaxElement) -> Option<Report> {
if_chain! {
if let NodeOrToken::Node(node) = node;
if let Some(let_in_expr) = LetIn::cast(node.clone());
let entries = let_in_expr.entries();
let inherits = let_in_expr.inherits();
if entries.count() == 0;
if inherits.count() == 0;
if let Some(body) = let_in_expr.body();
then {
let at = node.text_range();
let replacement = body;
let message = "This let-in expression has no entries";
Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
} else {
None
}
}
}
}
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