5 files changed, 60 insertions, 54 deletions

diff --git a/crates/hir/src/diagnostics.rs b/crates/hir/src/diagnostics.rs
index 158626dc0..ec0a8fe41 100644
--- a/crates/hir/src/diagnostics.rs
+++ b/crates/hir/src/diagnostics.rs
@@ -32,7 +32,7 @@ macro_rules! diagnostics {
     };
 }
 
-diagnostics![UnresolvedModule, MissingFields];
+diagnostics![UnresolvedModule, UnresolvedExternCrate, MissingFields];
 
 #[derive(Debug)]
 pub struct UnresolvedModule {
@@ -40,28 +40,9 @@ pub struct UnresolvedModule {
     pub candidate: String,
 }
 
-// Diagnostic: unresolved-extern-crate
-//
-// This diagnostic is triggered if rust-analyzer is unable to discover referred extern crate.
 #[derive(Debug)]
 pub struct UnresolvedExternCrate {
-    pub file: HirFileId,
-    pub item: AstPtr<ast::ExternCrate>,
-}
-
-impl Diagnostic for UnresolvedExternCrate {
-    fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("unresolved-extern-crate")
-    }
-    fn message(&self) -> String {
-        "unresolved extern crate".to_string()
-    }
-    fn display_source(&self) -> InFile<SyntaxNodePtr> {
-        InFile::new(self.file, self.item.clone().into())
-    }
-    fn as_any(&self) -> &(dyn Any + Send + 'static) {
-        self
-    }
+    pub decl: InFile<AstPtr<ast::ExternCrate>>,
 }
 
 #[derive(Debug)]
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 373134f62..f7883c469 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -484,10 +484,12 @@ impl Module {
                 }
                 DefDiagnosticKind::UnresolvedExternCrate { ast } => {
                     let item = ast.to_node(db.upcast());
-                    sink.push(UnresolvedExternCrate {
-                        file: ast.file_id,
-                        item: AstPtr::new(&item),
-                    });
+                    acc.push(
+                        UnresolvedExternCrate {
+                            decl: InFile::new(ast.file_id, AstPtr::new(&item)),
+                        }
+                        .into(),
+                    );
                 }
 
                 DefDiagnosticKind::UnresolvedImport { id, index } => {
diff --git a/crates/hir_def/src/nameres/tests/diagnostics.rs b/crates/hir_def/src/nameres/tests/diagnostics.rs
index c82deca9c..84d6fdc93 100644
--- a/crates/hir_def/src/nameres/tests/diagnostics.rs
+++ b/crates/hir_def/src/nameres/tests/diagnostics.rs
@@ -26,35 +26,6 @@ fn unresolved_import() {
 }
 
 #[test]
-fn unresolved_extern_crate() {
-    check_diagnostics(
-        r"
-        //- /main.rs crate:main deps:core
-        extern crate core;
-          extern crate doesnotexist;
-        //^^^^^^^^^^^^^^^^^^^^^^^^^^ UnresolvedExternCrate
-        //- /lib.rs crate:core
-        ",
-    );
-}
-
-#[test]
-fn extern_crate_self_as() {
-    cov_mark::check!(extern_crate_self_as);
-    check_diagnostics(
-        r"
-        //- /lib.rs
-          extern crate doesnotexist;
-        //^^^^^^^^^^^^^^^^^^^^^^^^^^ UnresolvedExternCrate
-        // Should not error.
-        extern crate self as foo;
-        struct Foo;
-        use foo::Foo as Bar;
-        ",
-    );
-}
-
-#[test]
 fn dedup_unresolved_import_from_unresolved_crate() {
     check_diagnostics(
         r"
diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 3307e240b..1fbb7131d 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -5,6 +5,7 @@
 //! original files. So we need to map the ranges.
 
 mod unresolved_module;
+mod unresolved_extern_crate;
 mod missing_fields;
 
 mod fixes;
@@ -229,8 +230,10 @@ pub(crate) fn diagnostics(
 
     let ctx = DiagnosticsContext { config, sema, resolve };
     for diag in diags {
+        #[rustfmt::skip]
         let d = match diag {
             AnyDiagnostic::UnresolvedModule(d) => unresolved_module::unresolved_module(&ctx, &d),
+            AnyDiagnostic::UnresolvedExternCrate(d) => unresolved_extern_crate::unresolved_extern_crate(&ctx, &d),
             AnyDiagnostic::MissingFields(d) => missing_fields::missing_fields(&ctx, &d),
         };
         if let Some(code) = d.code {
diff --git a/crates/ide/src/diagnostics/unresolved_extern_crate.rs b/crates/ide/src/diagnostics/unresolved_extern_crate.rs
new file mode 100644
index 000000000..2ea79c2ee
--- /dev/null
+++ b/crates/ide/src/diagnostics/unresolved_extern_crate.rs
@@ -0,0 +1,49 @@
+use crate::diagnostics::{Diagnostic, DiagnosticsContext};
+
+// Diagnostic: unresolved-extern-crate
+//
+// This diagnostic is triggered if rust-analyzer is unable to discover referred extern crate.
+pub(super) fn unresolved_extern_crate(
+    ctx: &DiagnosticsContext<'_>,
+    d: &hir::UnresolvedExternCrate,
+) -> Diagnostic {
+    Diagnostic::new(
+        "unresolved-extern-crate",
+        "unresolved extern crate",
+        ctx.sema.diagnostics_display_range(d.decl.clone().map(|it| it.into())).range,
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::diagnostics::tests::check_diagnostics;
+
+    #[test]
+    fn unresolved_extern_crate() {
+        check_diagnostics(
+            r#"
+//- /main.rs crate:main deps:core
+extern crate core;
+  extern crate doesnotexist;
+//^^^^^^^^^^^^^^^^^^^^^^^^^^ unresolved extern crate
+//- /lib.rs crate:core
+"#,
+        );
+    }
+
+    #[test]
+    fn extern_crate_self_as() {
+        cov_mark::check!(extern_crate_self_as);
+        check_diagnostics(
+            r#"
+//- /lib.rs
+  extern crate doesnotexist;
+//^^^^^^^^^^^^^^^^^^^^^^^^^^ unresolved extern crate
+// Should not error.
+extern crate self as foo;
+struct Foo;
+use foo::Foo as Bar;
+"#,
+        );
+    }
+}