src/tools/clippy/clippy_lints/src/methods/verbose_file_reads.rs

   1 use clippy_utils::diagnostics::span_lint_and_help;
   2 use clippy_utils::is_trait_method;
   3 use clippy_utils::ty::is_type_diagnostic_item;
   4 use rustc_hir::{Expr, ExprKind, QPath};
   5 use rustc_lint::LateContext;
   6 use rustc_span::sym;
   7
   8 use super::VERBOSE_FILE_READS;
   9
  10 pub(super) const READ_TO_END_MSG: (&str, &str) = ("use of `File::read_to_end`", "consider using `fs::read` instead");
  11 pub(super) const READ_TO_STRING_MSG: (&str, &str) = (
  12     "use of `File::read_to_string`",
  13     "consider using `fs::read_to_string` instead",
  14 );
  15
  16 pub(super) fn check<'tcx>(
  17     cx: &LateContext<'tcx>,
  18     expr: &'tcx Expr<'_>,
  19     recv: &'tcx Expr<'_>,
  20     (msg, help): (&str, &str),
  21 ) {
  22     if is_trait_method(cx, expr, sym::IoRead)
  23         && matches!(recv.kind, ExprKind::Path(QPath::Resolved(None, _)))
  24         && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty_adjusted(recv).peel_refs(), sym::File)
  25     {
  26         span_lint_and_help(cx, VERBOSE_FILE_READS, expr.span, msg, None, help);
  27     }
  28 }