use crate::{Metadata, Report, Rule, Suggestion}; use if_chain::if_chain; use macros::lint; use rnix::{ types::{Pattern, TokenWrapper, TypedNode}, NodeOrToken, SyntaxElement, SyntaxKind, }; /// ## What it does /// Checks for binds of the form `inputs @ { ... }` in function /// arguments. /// /// ## Why is this bad? /// The variadic pattern here is redundant, as it does not capture /// anything. /// /// ## Example /// /// ```nix /// inputs @ { ... }: inputs.nixpkgs /// ``` /// /// Remove the pattern altogether: /// /// ```nix /// inputs: inputs.nixpkgs /// ``` #[lint( name = "redundant pattern bind", note = "Found redundant pattern bind in function argument", code = 11, match_with = SyntaxKind::NODE_PATTERN )] struct RedundantPatternBind; impl Rule for RedundantPatternBind { fn validate(&self, node: &SyntaxElement) -> Option { if_chain! { if let NodeOrToken::Node(node) = node; if let Some(pattern) = Pattern::cast(node.clone()); // no patterns within `{ }` if pattern.entries().count() == 0; // pattern is just ellipsis if pattern.ellipsis(); // pattern is bound if let Some(ident) = pattern.at(); then { let at = node.text_range(); let message = format!("This pattern bind is redundant, use `{}` instead", ident.as_str()); let replacement = ident.node().clone(); Some(self.report().suggest(at, message, Suggestion::new(at, replacement))) } else { None } } } }