rust/clippy_lints/src/methods/expect_used.rs
2021-03-31 13:25:55 -05:00

32 lines
991 B
Rust

use clippy_utils::diagnostics::span_lint_and_help;
use clippy_utils::ty::is_type_diagnostic_item;
use rustc_hir as hir;
use rustc_lint::LateContext;
use rustc_span::sym;
use super::EXPECT_USED;
/// lint use of `expect()` for `Option`s and `Result`s
pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>) {
let obj_ty = cx.typeck_results().expr_ty(recv).peel_refs();
let mess = if is_type_diagnostic_item(cx, obj_ty, sym::option_type) {
Some((EXPECT_USED, "an Option", "None"))
} else if is_type_diagnostic_item(cx, obj_ty, sym::result_type) {
Some((EXPECT_USED, "a Result", "Err"))
} else {
None
};
if let Some((lint, kind, none_value)) = mess {
span_lint_and_help(
cx,
lint,
expr.span,
&format!("used `expect()` on `{}` value", kind,),
None,
&format!("if this value is an `{}`, it will panic", none_value,),
);
}
}