2 files changed, 102 insertions, 1 deletions

diff --git a/src/tools/jsondoclint/src/validator.rs b/src/tools/jsondoclint/src/validator.rs
index f7c752033c5..791b231c27a 100644
--- a/src/tools/jsondoclint/src/validator.rs
+++ b/src/tools/jsondoclint/src/validator.rs
@@ -303,6 +303,12 @@ impl<'a> Validator<'a> {
             PathKind::Trait => self.add_trait_or_alias_id(&x.id),
             PathKind::Type => self.add_type_id(&x.id),
         }
+
+        // FIXME: More robust support for checking things in $.index also exist in $.paths
+        if !self.krate.paths.contains_key(&x.id) {
+            self.fail(&x.id, ErrorKind::Custom(format!("No entry in '$.paths' for {x:?}")));
+        }
+
         if let Some(args) = &x.args {
             self.check_generic_args(&**args);
         }
diff --git a/src/tools/jsondoclint/src/validator/tests.rs b/src/tools/jsondoclint/src/validator/tests.rs
index e842e1318db..7fcb8ffd1f9 100644
--- a/src/tools/jsondoclint/src/validator/tests.rs
+++ b/src/tools/jsondoclint/src/validator/tests.rs
@@ -1,5 +1,5 @@
 use rustc_hash::FxHashMap;
-use rustdoc_json_types::{FORMAT_VERSION, Item, ItemKind, Visibility};
+use rustdoc_json_types::{Abi, FORMAT_VERSION, FunctionHeader, Item, ItemKind, Visibility};
 
 use super::*;
 use crate::json_find::SelectorPart;
@@ -103,6 +103,101 @@ fn errors_on_local_in_paths_and_not_index() {
 }
 
 #[test]
+fn errors_on_missing_path() {
+    // crate-name=foo
+    // ```
+    // pub struct Bar;
+    // pub fn mk_bar() -> Bar { ... }
+    // ```
+
+    let generics = Generics { params: vec![], where_predicates: vec![] };
+
+    let krate = Crate {
+        root: Id(0),
+        crate_version: None,
+        includes_private: false,
+        index: FxHashMap::from_iter([
+            (Id(0), Item {
+                id: Id(0),
+                crate_id: 0,
+                name: Some("foo".to_owned()),
+                span: None,
+                visibility: Visibility::Public,
+                docs: None,
+                links: FxHashMap::default(),
+                attrs: Vec::new(),
+                deprecation: None,
+                inner: ItemEnum::Module(Module {
+                    is_crate: true,
+                    items: vec![Id(1), Id(2)],
+                    is_stripped: false,
+                }),
+            }),
+            (Id(1), Item {
+                id: Id(0),
+                crate_id: 0,
+                name: Some("Bar".to_owned()),
+                span: None,
+                visibility: Visibility::Public,
+                docs: None,
+                links: FxHashMap::default(),
+                attrs: Vec::new(),
+                deprecation: None,
+                inner: ItemEnum::Struct(Struct {
+                    kind: StructKind::Unit,
+                    generics: generics.clone(),
+                    impls: vec![],
+                }),
+            }),
+            (Id(2), Item {
+                id: Id(0),
+                crate_id: 0,
+                name: Some("mk_bar".to_owned()),
+                span: None,
+                visibility: Visibility::Public,
+                docs: None,
+                links: FxHashMap::default(),
+                attrs: Vec::new(),
+                deprecation: None,
+                inner: ItemEnum::Function(Function {
+                    sig: FunctionSignature {
+                        inputs: vec![],
+                        output: Some(Type::ResolvedPath(Path {
+                            name: "Bar".to_owned(),
+                            id: Id(1),
+                            args: None,
+                        })),
+                        is_c_variadic: false,
+                    },
+                    generics,
+                    header: FunctionHeader {
+                        is_const: false,
+                        is_unsafe: false,
+                        is_async: false,
+                        abi: Abi::Rust,
+                    },
+                    has_body: true,
+                }),
+            }),
+        ]),
+        paths: FxHashMap::from_iter([(Id(0), ItemSummary {
+            crate_id: 0,
+            path: vec!["foo".to_owned()],
+            kind: ItemKind::Module,
+        })]),
+        external_crates: FxHashMap::default(),
+        format_version: rustdoc_json_types::FORMAT_VERSION,
+    };
+
+    check(&krate, &[Error {
+        kind: ErrorKind::Custom(
+            r#"No entry in '$.paths' for Path { name: "Bar", id: Id(1), args: None }"#.to_owned(),
+        ),
+        id: Id(1),
+    }]);
+}
+
+#[test]
 #[should_panic = "LOCAL_CRATE_ID is wrong"]
 fn checks_local_crate_id_is_correct() {
     let krate = Crate {