clippy_lints/src/methods/chars_cmp_with_unwrap.rs

   1 use clippy_utils::diagnostics::span_lint_and_sugg;
   2 use clippy_utils::method_chain_args;
   3 use clippy_utils::source::snippet_with_applicability;
   4 use if_chain::if_chain;
   5 use rustc_ast::ast;
   6 use rustc_errors::Applicability;
   7 use rustc_hir as hir;
   8 use rustc_lint::LateContext;
   9 use rustc_lint::Lint;
  10
  11 /// Wrapper fn for `CHARS_NEXT_CMP` and `CHARS_LAST_CMP` lints with `unwrap()`.
  12 pub(super) fn check(
  13     cx: &LateContext<'_>,
  14     info: &crate::methods::BinaryExprInfo<'_>,
  15     chain_methods: &[&str],
  16     lint: &'static Lint,
  17     suggest: &str,
  18 ) -> bool {
  19     if_chain! {
  20         if let Some(args) = method_chain_args(info.chain, chain_methods);
  21         if let hir::ExprKind::Lit(ref lit) = info.other.kind;
  22         if let ast::LitKind::Char(c) = lit.node;
  23         then {
  24             let mut applicability = Applicability::MachineApplicable;
  25             span_lint_and_sugg(
  26                 cx,
  27                 lint,
  28                 info.expr.span,
  29                 &format!("you should use the `{suggest}` method"),
  30                 "like this",
  31                 format!("{}{}.{suggest}('{}')",
  32                         if info.eq { "" } else { "!" },
  33                         snippet_with_applicability(cx, args[0].0.span, "..", &mut applicability),
  34                         c.escape_default()),
  35                 applicability,
  36             );
  37
  38             true
  39         } else {
  40             false
  41         }
  42     }
  43 }