Complete `self.` prefixed fields and methods inside methods

6 files changed, 165 insertions, 54 deletions

diff --git a/crates/ide_completion/src/completions.rs b/crates/ide_completion/src/completions.rs
index 151bf3783..0f0553a65 100644
--- a/crates/ide_completion/src/completions.rs
+++ b/crates/ide_completion/src/completions.rs
@@ -18,8 +18,10 @@ pub(crate) mod unqualified_path;
 
 use std::iter;
 
-use hir::known;
+use either::Either;
+use hir::{known, HasVisibility};
 use ide_db::SymbolKind;
+use rustc_hash::FxHashSet;
 
 use crate::{
     item::{Builder, CompletionKind},
@@ -69,18 +71,25 @@ impl Completions {
         items.into_iter().for_each(|item| self.add(item.into()))
     }
 
-    pub(crate) fn add_field(&mut self, ctx: &CompletionContext, field: hir::Field, ty: &hir::Type) {
-        let item = render_field(RenderContext::new(ctx), field, ty);
+    pub(crate) fn add_field(
+        &mut self,
+        ctx: &CompletionContext,
+        receiver: Option<String>,
+        field: hir::Field,
+        ty: &hir::Type,
+    ) {
+        let item = render_field(RenderContext::new(ctx), receiver, field, ty);
         self.add(item);
     }
 
     pub(crate) fn add_tuple_field(
         &mut self,
         ctx: &CompletionContext,
+        receiver: Option<String>,
         field: usize,
         ty: &hir::Type,
     ) {
-        let item = render_tuple_field(RenderContext::new(ctx), field, ty);
+        let item = render_tuple_field(RenderContext::new(ctx), receiver, field, ty);
         self.add(item);
     }
 
@@ -132,9 +141,11 @@ impl Completions {
         &mut self,
         ctx: &CompletionContext,
         func: hir::Function,
+        receiver: Option<String>,
         local_name: Option<hir::Name>,
     ) {
-        if let Some(item) = render_method(RenderContext::new(ctx), None, local_name, func) {
+        if let Some(item) = render_method(RenderContext::new(ctx), None, receiver, local_name, func)
+        {
             self.add(item)
         }
     }
@@ -243,3 +254,44 @@ fn complete_enum_variants(
         }
     }
 }
+
+fn complete_fields(
+    ctx: &CompletionContext,
+    receiver: &hir::Type,
+    mut f: impl FnMut(Either<hir::Field, usize>, hir::Type),
+) {
+    for receiver in receiver.autoderef(ctx.db) {
+        for (field, ty) in receiver.fields(ctx.db) {
+            if ctx.scope.module().map_or(false, |m| !field.is_visible_from(ctx.db, m)) {
+                // Skip private field. FIXME: If the definition location of the
+                // field is editable, we should show the completion
+                continue;
+            }
+            f(Either::Left(field), ty);
+        }
+        for (i, ty) in receiver.tuple_fields(ctx.db).into_iter().enumerate() {
+            // FIXME: Handle visibility
+            f(Either::Right(i), ty);
+        }
+    }
+}
+
+fn complete_methods(
+    ctx: &CompletionContext,
+    receiver: &hir::Type,
+    mut f: impl FnMut(hir::Function),
+) {
+    if let Some(krate) = ctx.krate {
+        let mut seen_methods = FxHashSet::default();
+        let traits_in_scope = ctx.scope.traits_in_scope();
+        receiver.iterate_method_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, func| {
+            if func.self_param(ctx.db).is_some()
+                && ctx.scope.module().map_or(true, |m| func.is_visible_from(ctx.db, m))
+                && seen_methods.insert(func.name(ctx.db))
+            {
+                f(func);
+            }
+            None::<()>
+        });
+    }
+}
diff --git a/crates/ide_completion/src/completions/dot.rs b/crates/ide_completion/src/completions/dot.rs
index fd9738743..93f7bd6d4 100644
--- a/crates/ide_completion/src/completions/dot.rs
+++ b/crates/ide_completion/src/completions/dot.rs
@@ -1,7 +1,6 @@
 //! Completes references after dot (fields and method calls).
 
-use hir::{HasVisibility, Type};
-use rustc_hash::FxHashSet;
+use either::Either;
 
 use crate::{context::CompletionContext, Completions};
 
@@ -20,42 +19,12 @@ pub(crate) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     if ctx.is_call {
         cov_mark::hit!(test_no_struct_field_completion_for_method_call);
     } else {
-        complete_fields(acc, ctx, &receiver_ty);
-    }
-    complete_methods(acc, ctx, &receiver_ty);
-}
-
-fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
-    for receiver in receiver.autoderef(ctx.db) {
-        for (field, ty) in receiver.fields(ctx.db) {
-            if ctx.scope.module().map_or(false, |m| !field.is_visible_from(ctx.db, m)) {
-                // Skip private field. FIXME: If the definition location of the
-                // field is editable, we should show the completion
-                continue;
-            }
-            acc.add_field(ctx, field, &ty);
-        }
-        for (i, ty) in receiver.tuple_fields(ctx.db).into_iter().enumerate() {
-            // FIXME: Handle visibility
-            acc.add_tuple_field(ctx, i, &ty);
-        }
-    }
-}
-
-fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
-    if let Some(krate) = ctx.krate {
-        let mut seen_methods = FxHashSet::default();
-        let traits_in_scope = ctx.scope.traits_in_scope();
-        receiver.iterate_method_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, func| {
-            if func.self_param(ctx.db).is_some()
-                && ctx.scope.module().map_or(true, |m| func.is_visible_from(ctx.db, m))
-                && seen_methods.insert(func.name(ctx.db))
-            {
-                acc.add_method(ctx, func, None);
-            }
-            None::<()>
+        super::complete_fields(ctx, &receiver_ty, |field, ty| match field {
+            Either::Left(field) => acc.add_field(ctx, None, field, &ty),
+            Either::Right(tuple_idx) => acc.add_tuple_field(ctx, None, tuple_idx, &ty),
         });
     }
+    super::complete_methods(ctx, &receiver_ty, |func| acc.add_method(ctx, func, None, None));
 }
 
 #[cfg(test)]
diff --git a/crates/ide_completion/src/completions/record.rs b/crates/ide_completion/src/completions/record.rs
index 227c08d01..0ac47cdbe 100644
--- a/crates/ide_completion/src/completions/record.rs
+++ b/crates/ide_completion/src/completions/record.rs
@@ -39,7 +39,7 @@ pub(crate) fn complete_record(acc: &mut Completions, ctx: &CompletionContext) ->
     };
 
     for (field, ty) in missing_fields {
-        acc.add_field(ctx, field, &ty);
+        acc.add_field(ctx, None, field, &ty);
     }
 
     Some(())
diff --git a/crates/ide_completion/src/completions/unqualified_path.rs b/crates/ide_completion/src/completions/unqualified_path.rs
index 9db8516d0..573a39996 100644
--- a/crates/ide_completion/src/completions/unqualified_path.rs
+++ b/crates/ide_completion/src/completions/unqualified_path.rs
@@ -11,6 +11,7 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
     if ctx.is_path_disallowed() || ctx.expects_item() {
         return;
     }
+
     if ctx.expects_assoc_item() {
         ctx.scope.process_all_names(&mut |name, def| {
             if let ScopeDef::MacroDef(macro_def) = def {
@@ -32,6 +33,7 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
         });
         return;
     }
+
     if let Some(hir::Adt::Enum(e)) =
         ctx.expected_type.as_ref().and_then(|ty| ty.strip_references().as_adt())
     {
@@ -45,6 +47,22 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
             cov_mark::hit!(skip_lifetime_completion);
             return;
         }
+        if let ScopeDef::Local(local) = &res {
+            if local.is_self(ctx.db) {
+                let ty = local.ty(ctx.db);
+                super::complete_fields(ctx, &ty, |field, ty| match field {
+                    either::Either::Left(field) => {
+                        acc.add_field(ctx, Some(name.to_string()), field, &ty)
+                    }
+                    either::Either::Right(tuple_idx) => {
+                        acc.add_tuple_field(ctx, Some(name.to_string()), tuple_idx, &ty)
+                    }
+                });
+                super::complete_methods(ctx, &ty, |func| {
+                    acc.add_method(ctx, func, Some(name.to_string()), None)
+                });
+            }
+        }
         acc.add_resolution(ctx, name, &res);
     });
 }
@@ -376,6 +394,36 @@ fn foo() {
     }
 
     #[test]
+    fn completes_qualified_fields_and_methods_in_methods() {
+        check(
+            r#"
+struct Foo { field: i32 }
+
+impl Foo { fn foo(&self) { $0 } }"#,
+            expect![[r#"
+                fd self.field i32
+                me self.foo() fn(&self)
+                lc self       &Foo
+                sp Self
+                st Foo
+            "#]],
+        );
+        check(
+            r#"
+struct Foo(i32);
+
+impl Foo { fn foo(&mut self) { $0 } }"#,
+            expect![[r#"
+                fd self.0     i32
+                me self.foo() fn(&mut self)
+                lc self       &mut Foo
+                sp Self
+                st Foo
+            "#]],
+        );
+    }
+
+    #[test]
     fn completes_prelude() {
         check(
             r#"
diff --git a/crates/ide_completion/src/render.rs b/crates/ide_completion/src/render.rs
index 425dd0247..bf59ff57b 100644
--- a/crates/ide_completion/src/render.rs
+++ b/crates/ide_completion/src/render.rs
@@ -25,18 +25,20 @@ use crate::{
 
 pub(crate) fn render_field<'a>(
     ctx: RenderContext<'a>,
+    receiver: Option<String>,
     field: hir::Field,
     ty: &hir::Type,
 ) -> CompletionItem {
-    Render::new(ctx).render_field(field, ty)
+    Render::new(ctx).render_field(receiver, field, ty)
 }
 
 pub(crate) fn render_tuple_field<'a>(
     ctx: RenderContext<'a>,
+    receiver: Option<String>,
     field: usize,
     ty: &hir::Type,
 ) -> CompletionItem {
-    Render::new(ctx).render_tuple_field(field, ty)
+    Render::new(ctx).render_tuple_field(receiver, field, ty)
 }
 
 pub(crate) fn render_resolution<'a>(
@@ -126,11 +128,19 @@ impl<'a> Render<'a> {
         Render { ctx }
     }
 
-    fn render_field(&self, field: hir::Field, ty: &hir::Type) -> CompletionItem {
+    fn render_field(
+        &self,
+        receiver: Option<String>,
+        field: hir::Field,
+        ty: &hir::Type,
+    ) -> CompletionItem {
         let is_deprecated = self.ctx.is_deprecated(field);
         let name = field.name(self.ctx.db()).to_string();
-        let mut item =
-            CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), name.clone());
+        let mut item = CompletionItem::new(
+            CompletionKind::Reference,
+            self.ctx.source_range(),
+            receiver.map_or_else(|| name.to_string(), |receiver| format!("{}.{}", receiver, name)),
+        );
         item.kind(SymbolKind::Field)
             .detail(ty.display(self.ctx.db()).to_string())
             .set_documentation(field.docs(self.ctx.db()))
@@ -151,11 +161,17 @@ impl<'a> Render<'a> {
         item.build()
     }
 
-    fn render_tuple_field(&self, field: usize, ty: &hir::Type) -> CompletionItem {
+    fn render_tuple_field(
+        &self,
+        receiver: Option<String>,
+        field: usize,
+        ty: &hir::Type,
+    ) -> CompletionItem {
         let mut item = CompletionItem::new(
             CompletionKind::Reference,
             self.ctx.source_range(),
-            field.to_string(),
+            receiver
+                .map_or_else(|| field.to_string(), |receiver| format!("{}.{}", receiver, field)),
         );
 
         item.kind(SymbolKind::Field).detail(ty.display(self.ctx.db()).to_string());
diff --git a/crates/ide_completion/src/render/function.rs b/crates/ide_completion/src/render/function.rs
index 63bd66926..b3ba6114d 100644
--- a/crates/ide_completion/src/render/function.rs
+++ b/crates/ide_completion/src/render/function.rs
@@ -20,23 +20,25 @@ pub(crate) fn render_fn<'a>(
     fn_: hir::Function,
 ) -> Option<CompletionItem> {
     let _p = profile::span("render_fn");
-    Some(FunctionRender::new(ctx, local_name, fn_, false)?.render(import_to_add))
+    Some(FunctionRender::new(ctx, None, local_name, fn_, false)?.render(import_to_add))
 }
 
 pub(crate) fn render_method<'a>(
     ctx: RenderContext<'a>,
     import_to_add: Option<ImportEdit>,
+    receiver: Option<String>,
     local_name: Option<hir::Name>,
     fn_: hir::Function,
 ) -> Option<CompletionItem> {
     let _p = profile::span("render_method");
-    Some(FunctionRender::new(ctx, local_name, fn_, true)?.render(import_to_add))
+    Some(FunctionRender::new(ctx, receiver, local_name, fn_, true)?.render(import_to_add))
 }
 
 #[derive(Debug)]
 struct FunctionRender<'a> {
     ctx: RenderContext<'a>,
     name: String,
+    receiver: Option<String>,
     func: hir::Function,
     ast_node: Fn,
     is_method: bool,
@@ -45,6 +47,7 @@ struct FunctionRender<'a> {
 impl<'a> FunctionRender<'a> {
     fn new(
         ctx: RenderContext<'a>,
+        receiver: Option<String>,
         local_name: Option<hir::Name>,
         fn_: hir::Function,
         is_method: bool,
@@ -52,11 +55,14 @@ impl<'a> FunctionRender<'a> {
         let name = local_name.unwrap_or_else(|| fn_.name(ctx.db())).to_string();
         let ast_node = fn_.source(ctx.db())?.value;
 
-        Some(FunctionRender { ctx, name, func: fn_, ast_node, is_method })
+        Some(FunctionRender { ctx, name, receiver, func: fn_, ast_node, is_method })
     }
 
-    fn render(self, import_to_add: Option<ImportEdit>) -> CompletionItem {
+    fn render(mut self, import_to_add: Option<ImportEdit>) -> CompletionItem {
         let params = self.params();
+        if let Some(receiver) = &self.receiver {
+            self.name = format!("{}.{}", receiver, &self.name)
+        }
         let mut item = CompletionItem::new(
             CompletionKind::Reference,
             self.ctx.source_range(),
@@ -148,7 +154,7 @@ impl<'a> FunctionRender<'a> {
         };
 
         let mut params_pats = Vec::new();
-        let params_ty = if self.ctx.completion.dot_receiver.is_some() {
+        let params_ty = if self.ctx.completion.dot_receiver.is_some() || self.receiver.is_some() {
             self.func.method_params(self.ctx.db()).unwrap_or_default()
         } else {
             if let Some(s) = ast_params.self_param() {
@@ -255,6 +261,26 @@ fn bar(s: &S) {
 }
 "#,
         );
+
+        check_edit(
+            "self.foo",
+            r#"
+struct S {}
+impl S {
+    fn foo(&self, x: i32) {
+        $0
+    }
+}
+"#,
+            r#"
+struct S {}
+impl S {
+    fn foo(&self, x: i32) {
+        self.foo(${1:x})$0
+    }
+}
+"#,
+        );
     }
 
     #[test]