Add support for goto definition and hover on Self

This fixes #943

4 files changed, 190 insertions, 26 deletions

diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index ea20cd15a..4a9921a85 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -205,19 +205,8 @@ pub fn resolver_for_position(db: &impl HirDatabase, position: FilePosition) -> R
                         // TODO const/static/array length
                         None
                     }
-                } else if let Some(module) = ast::Module::cast(node) {
-                    Some(module_from_declaration(db, file_id, module)?.resolver(db))
-                } else if let Some(_) = ast::SourceFile::cast(node) {
-                    Some(module_from_source(db, file_id.into(), None)?.resolver(db))
-                } else if let Some(s) = ast::StructDef::cast(node) {
-                    let module = module_from_child_node(db, file_id, s.syntax())?;
-                    Some(struct_from_module(db, module, s).resolver(db))
-                } else if let Some(e) = ast::EnumDef::cast(node) {
-                    let module = module_from_child_node(db, file_id, e.syntax())?;
-                    Some(enum_from_module(db, module, e).resolver(db))
                 } else {
-                    // TODO add missing cases
-                    None
+                    try_get_resolver_for_node(db, file_id, node)
                 }
             })
         })
@@ -236,20 +225,32 @@ pub fn resolver_for_node(db: &impl HirDatabase, file_id: FileId, node: &SyntaxNo
                     // TODO const/static/array length
                     None
                 }
-            } else if let Some(module) = ast::Module::cast(node) {
-                Some(module_from_declaration(db, file_id, module)?.resolver(db))
-            } else if let Some(_) = ast::SourceFile::cast(node) {
-                Some(module_from_source(db, file_id.into(), None)?.resolver(db))
-            } else if let Some(s) = ast::StructDef::cast(node) {
-                let module = module_from_child_node(db, file_id, s.syntax())?;
-                Some(struct_from_module(db, module, s).resolver(db))
-            } else if let Some(e) = ast::EnumDef::cast(node) {
-                let module = module_from_child_node(db, file_id, e.syntax())?;
-                Some(enum_from_module(db, module, e).resolver(db))
             } else {
-                // TODO add missing cases
-                None
+                try_get_resolver_for_node(db, file_id, node)
             }
         })
         .unwrap_or_default()
 }
+
+fn try_get_resolver_for_node(
+    db: &impl HirDatabase,
+    file_id: FileId,
+    node: &SyntaxNode,
+) -> Option<Resolver> {
+    if let Some(module) = ast::Module::cast(node) {
+        Some(module_from_declaration(db, file_id, module)?.resolver(db))
+    } else if let Some(_) = ast::SourceFile::cast(node) {
+        Some(module_from_source(db, file_id.into(), None)?.resolver(db))
+    } else if let Some(s) = ast::StructDef::cast(node) {
+        let module = module_from_child_node(db, file_id, s.syntax())?;
+        Some(struct_from_module(db, module, s).resolver(db))
+    } else if let Some(e) = ast::EnumDef::cast(node) {
+        let module = module_from_child_node(db, file_id, e.syntax())?;
+        Some(enum_from_module(db, module, e).resolver(db))
+    } else if let Some(f) = ast::FnDef::cast(node) {
+        function_from_source(db, file_id, f).map(|f| f.resolver(db))
+    } else {
+        // TODO add missing cases
+        None
+    }
+}
diff --git a/crates/ra_ide_api/src/goto_definition.rs b/crates/ra_ide_api/src/goto_definition.rs
index dd5f9f31c..d4e10b69c 100644
--- a/crates/ra_ide_api/src/goto_definition.rs
+++ b/crates/ra_ide_api/src/goto_definition.rs
@@ -121,8 +121,12 @@ pub(crate) fn reference_definition(
             Some(Resolution::GenericParam(..)) => {
                 // TODO: go to the generic param def
             }
-            Some(Resolution::SelfType(_impl_block)) => {
-                // TODO: go to the implemented type
+            Some(Resolution::SelfType(impl_block)) => {
+                let ty = impl_block.target_ty(db);
+
+                if let hir::Ty::Adt { def_id, .. } = ty {
+                    return Exact(NavigationTarget::from_adt_def(db, def_id));
+                }
             }
             None => {
                 // If we failed to resolve then check associated items
@@ -337,6 +341,94 @@ mod tests {
             "spam NAMED_FIELD_DEF FileId(1) [17; 26) [17; 21)",
         );
     }
+    #[test]
+    fn goto_definition_on_self() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            impl Foo {
+                pub fn new() -> Self {
+                    Self<|> {}
+                }
+            }
+            ",
+            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            impl Foo {
+                pub fn new() -> Self<|> {
+                    Self {}
+                }
+            }
+            ",
+            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            enum Foo { A }
+            impl Foo {
+                pub fn new() -> Self<|> {
+                    Foo::A
+                }
+            }
+            ",
+            "Foo ENUM_DEF FileId(1) [0; 14) [5; 8)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            enum Foo { A }
+            impl Foo {
+                pub fn thing(a: &Self<|>) {
+                }
+            }
+            ",
+            "Foo ENUM_DEF FileId(1) [0; 14) [5; 8)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_on_self_in_trait_impl() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            trait Make {
+                fn new() -> Self;
+            }
+            impl Make for Foo {
+                fn new() -> Self {
+                    Self<|> {}
+                }
+            }
+            ",
+            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            trait Make {
+                fn new() -> Self;
+            }
+            impl Make for Foo {
+                fn new() -> Self<|> {
+                    Self{}
+                }
+            }
+            ",
+            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+        );
+    }
 
     #[test]
     fn goto_definition_works_when_used_on_definition_name_itself() {
diff --git a/crates/ra_ide_api/src/hover.rs b/crates/ra_ide_api/src/hover.rs
index 638c24e31..f14001e84 100644
--- a/crates/ra_ide_api/src/hover.rs
+++ b/crates/ra_ide_api/src/hover.rs
@@ -557,4 +557,62 @@ mod tests {
         assert_eq!(trim_markup_opt(hover.info.first()), Some("const C: u32"));
         assert_eq!(hover.info.is_exact(), true);
     }
+
+    #[test]
+    fn test_hover_self() {
+        let (analysis, position) = single_file_with_position(
+            "
+            struct Thing { x: u32 };
+            impl Thing {
+                fn new() -> Self {
+                    Self<|> { x: 0 }
+                }
+            }
+        ",
+        );
+        let hover = analysis.hover(position).unwrap().unwrap();
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("struct Thing"));
+        assert_eq!(hover.info.is_exact(), true);
+
+        let (analysis, position) = single_file_with_position(
+            "
+            struct Thing { x: u32 };
+            impl Thing {
+                fn new() -> Self<|> {
+                    Self { x: 0 }
+                }
+            }
+            ",
+        );
+        let hover = analysis.hover(position).unwrap().unwrap();
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("struct Thing"));
+        assert_eq!(hover.info.is_exact(), true);
+
+        let (analysis, position) = single_file_with_position(
+            "
+            enum Thing { A };
+            impl Thing {
+                pub fn new() -> Self<|> {
+                    Thing::A
+                }
+            }
+            ",
+        );
+        let hover = analysis.hover(position).unwrap().unwrap();
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("enum Thing"));
+        assert_eq!(hover.info.is_exact(), true);
+
+        let (analysis, position) = single_file_with_position(
+            "
+            enum Thing { A };
+            impl Thing {
+                pub fn thing(a: Self<|>) {
+                }
+            }
+            ",
+        );
+        let hover = analysis.hover(position).unwrap().unwrap();
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("enum Thing"));
+        assert_eq!(hover.info.is_exact(), true);
+    }
 }
diff --git a/crates/ra_ide_api/src/navigation_target.rs b/crates/ra_ide_api/src/navigation_target.rs
index d806cb368..f6d7f3192 100644
--- a/crates/ra_ide_api/src/navigation_target.rs
+++ b/crates/ra_ide_api/src/navigation_target.rs
@@ -126,6 +126,19 @@ impl NavigationTarget {
         }
     }
 
+    pub(crate) fn from_adt_def(db: &RootDatabase, adt_def: hir::AdtDef) -> NavigationTarget {
+        match adt_def {
+            hir::AdtDef::Struct(s) => {
+                let (file_id, node) = s.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+            hir::AdtDef::Enum(s) => {
+                let (file_id, node) = s.source(db);
+                NavigationTarget::from_named(file_id.original_file(db), &*node)
+            }
+        }
+    }
+
     pub(crate) fn from_def(db: &RootDatabase, module_def: hir::ModuleDef) -> NavigationTarget {
         match module_def {
             hir::ModuleDef::Module(module) => NavigationTarget::from_module(db, module),