Go to Implementation for structs and enums

crates/ra_ide_api/src/impls.rs

@@ -0,0 +1,121 @@
+use ra_db::{SourceDatabase};
+use ra_syntax::{
+    AstNode, ast,
+    algo::find_node_at_offset,
+};
+use hir::{db::HirDatabase, source_binder};
+
+use crate::{FilePosition, NavigationTarget, db::RootDatabase, RangeInfo};
+
+pub(crate) fn goto_implementation(
+    db: &RootDatabase,
+    position: FilePosition,
+) -> Option<RangeInfo<Vec<NavigationTarget>>> {
+    let file = db.parse(position.file_id);
+    let syntax = file.syntax();
+
+    let krate_id = db.crate_for(position.file_id).pop()?;
+    let krate = hir::Crate { crate_id: krate_id };
+    let module = source_binder::module_from_position(db, position)?;
+
+    let node = find_node_at_offset::<ast::NominalDef>(syntax, position.offset)?;
+    let ty = match node.kind() {
+        ast::NominalDefKind::StructDef(def) => {
+            source_binder::struct_from_module(db, module, &def).ty(db)
+        }
+        ast::NominalDefKind::EnumDef(def) => {
+            source_binder::enum_from_module(db, module, &def).ty(db)
+        }
+    };
+
+    let impls = db.impls_in_crate(krate);
+
+    let navs = impls
+        .lookup_impl_blocks(db, &ty)
+        .map(|(module, imp)| NavigationTarget::from_impl_block(db, module, &imp));
+
+    Some(RangeInfo::new(node.syntax().range(), navs.collect()))
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mock_analysis::analysis_and_position;
+
+    fn check_goto(fixuture: &str, expected: &[&str]) {
+        let (analysis, pos) = analysis_and_position(fixuture);
+
+        let navs = analysis.goto_implementation(pos).unwrap().unwrap().info;
+        assert_eq!(navs.len(), expected.len());
+        navs.into_iter()
+            .enumerate()
+            .for_each(|(i, nav)| nav.assert_match(expected[i]));
+    }
+
+    #[test]
+    fn goto_implementation_works() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo<|>;
+            impl Foo {}
+            ",
+            &["impl IMPL_BLOCK FileId(1) [12; 23)"],
+        );
+    }
+
+    #[test]
+    fn goto_implementation_works_multiple_blocks() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo<|>;
+            impl Foo {}
+            impl Foo {}
+            ",
+            &[
+                "impl IMPL_BLOCK FileId(1) [12; 23)",
+                "impl IMPL_BLOCK FileId(1) [24; 35)",
+            ],
+        );
+    }
+
+    #[test]
+    fn goto_implementation_works_multiple_mods() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo<|>;
+            mod a {
+                impl super::Foo {}
+            }
+            mod b {
+                impl super::Foo {}
+            }
+            ",
+            &[
+                "impl IMPL_BLOCK FileId(1) [24; 42)",
+                "impl IMPL_BLOCK FileId(1) [57; 75)",
+            ],
+        );
+    }
+
+    #[test]
+    fn goto_implementation_works_multiple_files() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo<|>;
+            mod a;
+            mod b;
+            //- /a.rs
+            impl crate::Foo {}
+            //- /b.rs
+            impl crate::Foo {}
+            ",
+            &[
+                "impl IMPL_BLOCK FileId(2) [0; 18)",
+                "impl IMPL_BLOCK FileId(3) [0; 18)",
+            ],
+        );
+    }
+}