2 use rustc::{declare_lint, lint_array};
4 use crate::utils::{get_trait_def_id, paths, span_lint};
6 /// **What it does:** Checks for mis-uses of the serde API.
8 /// **Why is this bad?** Serde is very finnicky about how its API should be
9 /// used, but the type system can't be used to enforce it (yet?).
11 /// **Known problems:** None.
13 /// **Example:** Implementing `Visitor::visit_string` but not
14 /// `Visitor::visit_str`.
15 declare_clippy_lint! {
18 "various things that will negatively affect your serde experience"
22 #[derive(Copy, Clone)]
25 impl LintPass for Serde {
26 fn get_lints(&self) -> LintArray {
27 lint_array!(SERDE_API_MISUSE)
31 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Serde {
32 fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item) {
33 if let ItemKind::Impl(_, _, _, _, Some(ref trait_ref), _, ref items) = item.node {
34 let did = trait_ref.path.def.def_id();
35 if let Some(visit_did) = get_trait_def_id(cx, &paths::SERDE_DE_VISITOR) {
37 let mut seen_str = None;
38 let mut seen_string = None;
40 match &*item.ident.as_str() {
41 "visit_str" => seen_str = Some(item.span),
42 "visit_string" => seen_string = Some(item.span),
46 if let Some(span) = seen_string {
47 if seen_str.is_none() {
52 "you should not implement `visit_string` without also implementing `visit_str`",