7 files changed, 140 insertions, 18 deletions

diff --git a/crates/ra_ide/src/completion/complete_trait_impl.rs b/crates/ra_ide/src/completion/complete_trait_impl.rs
index fab02945c..2ec0e7ce9 100644
--- a/crates/ra_ide/src/completion/complete_trait_impl.rs
+++ b/crates/ra_ide/src/completion/complete_trait_impl.rs
@@ -142,11 +142,11 @@ fn add_function_impl(
         CompletionItemKind::Function
     };
 
-    let snippet = format!("{} {{}}", display);
+    let snippet = format!("{} {{\n    $0\n}}", display);
 
     let range = TextRange::from_to(fn_def_node.text_range().start(), ctx.source_range().end());
 
-    builder.text_edit(TextEdit::replace(range, snippet)).kind(completion_kind).add_to(acc);
+    builder.snippet_edit(TextEdit::replace(range, snippet)).kind(completion_kind).add_to(acc);
 }
 
 fn add_type_alias_impl(
@@ -217,9 +217,10 @@ fn make_const_compl_syntax(const_: &ast::ConstDef) -> String {
 
 #[cfg(test)]
 mod tests {
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
     use insta::assert_debug_snapshot;
 
+    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
+
     fn complete(code: &str) -> Vec<CompletionItem> {
         do_completion(code, CompletionKind::Magic)
     }
@@ -255,7 +256,7 @@ mod tests {
                 label: "fn test()",
                 source_range: [209; 210),
                 delete: [209; 210),
-                insert: "fn test() {}",
+                insert: "fn test() {\n    $0\n}",
                 kind: Function,
                 lookup: "test",
             },
@@ -313,7 +314,7 @@ mod tests {
                 label: "fn test()",
                 source_range: [139; 140),
                 delete: [139; 140),
-                insert: "fn test() {}",
+                insert: "fn test() {\n    $0\n}",
                 kind: Function,
                 lookup: "test",
             },
@@ -342,7 +343,7 @@ mod tests {
                 label: "fn foo()",
                 source_range: [141; 142),
                 delete: [138; 142),
-                insert: "fn foo() {}",
+                insert: "fn foo() {\n    $0\n}",
                 kind: Function,
                 lookup: "foo",
             },
@@ -374,7 +375,7 @@ mod tests {
                 label: "fn foo_bar()",
                 source_range: [200; 201),
                 delete: [197; 201),
-                insert: "fn foo_bar() {}",
+                insert: "fn foo_bar() {\n    $0\n}",
                 kind: Function,
                 lookup: "foo_bar",
             },
@@ -425,7 +426,7 @@ mod tests {
                 label: "fn foo()",
                 source_range: [144; 145),
                 delete: [141; 145),
-                insert: "fn foo<T>() {}",
+                insert: "fn foo<T>() {\n    $0\n}",
                 kind: Function,
                 lookup: "foo",
             },
@@ -454,7 +455,7 @@ mod tests {
                 label: "fn foo()",
                 source_range: [166; 167),
                 delete: [163; 167),
-                insert: "fn foo<T>()\nwhere T: Into<String> {}",
+                insert: "fn foo<T>()\nwhere T: Into<String> {\n    $0\n}",
                 kind: Function,
                 lookup: "foo",
             },
diff --git a/crates/ra_ide/src/completion/complete_unqualified_path.rs b/crates/ra_ide/src/completion/complete_unqualified_path.rs
index 2d8e0776c..ad5fdcc4e 100644
--- a/crates/ra_ide/src/completion/complete_unqualified_path.rs
+++ b/crates/ra_ide/src/completion/complete_unqualified_path.rs
@@ -1,6 +1,10 @@
 //! Completion of names from the current scope, e.g. locals and imported items.
 
+use hir::ScopeDef;
+use test_utils::tested_by;
+
 use crate::completion::{CompletionContext, Completions};
+use ra_syntax::AstNode;
 
 pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionContext) {
     if !ctx.is_trivial_path {
@@ -14,12 +18,23 @@ pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
         return;
     }
 
-    ctx.scope().process_all_names(&mut |name, res| acc.add_resolution(ctx, name.to_string(), &res));
+    ctx.scope().process_all_names(&mut |name, res| {
+        if ctx.use_item_syntax.is_some() {
+            if let (ScopeDef::Unknown, Some(name_ref)) = (&res, &ctx.name_ref_syntax) {
+                if name_ref.syntax().text() == name.to_string().as_str() {
+                    tested_by!(self_fulfilling_completion);
+                    return;
+                }
+            }
+        }
+        acc.add_resolution(ctx, name.to_string(), &res)
+    });
 }
 
 #[cfg(test)]
 mod tests {
     use insta::assert_debug_snapshot;
+    use test_utils::covers;
 
     use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
 
@@ -28,6 +43,29 @@ mod tests {
     }
 
     #[test]
+    fn self_fulfilling_completion() {
+        covers!(self_fulfilling_completion);
+        assert_debug_snapshot!(
+            do_reference_completion(
+                r#"
+                use foo<|>
+                use std::collections;
+                "#,
+            ),
+            @r###"
+            [
+                CompletionItem {
+                    label: "collections",
+                    source_range: [21; 24),
+                    delete: [21; 24),
+                    insert: "collections",
+                },
+            ]
+            "###
+        );
+    }
+
+    #[test]
     fn bind_pat_and_path_ignore_at() {
         assert_debug_snapshot!(
             do_reference_completion(
diff --git a/crates/ra_ide/src/diagnostics.rs b/crates/ra_ide/src/diagnostics.rs
index 901ad104c..e7e201709 100644
--- a/crates/ra_ide/src/diagnostics.rs
+++ b/crates/ra_ide/src/diagnostics.rs
@@ -1,4 +1,8 @@
-//! FIXME: write short doc here
+//! Collects diagnostics & fixits  for a single file.
+//!
+//! The tricky bit here is that diagnostics are produced by hir in terms of
+//! macro-expanded files, but we need to present them to the users in terms of
+//! original files. So we need to map the ranges.
 
 use std::cell::RefCell;
 
@@ -46,7 +50,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
     let mut sink = DiagnosticSink::new(|d| {
         res.borrow_mut().push(Diagnostic {
             message: d.message(),
-            range: d.highlight_range(),
+            range: sema.diagnostics_range(d).range,
             severity: Severity::Error,
             fix: None,
         })
@@ -62,7 +66,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
         let create_file = FileSystemEdit::CreateFile { source_root, path };
         let fix = SourceChange::file_system_edit("create module", create_file);
         res.borrow_mut().push(Diagnostic {
-            range: d.highlight_range(),
+            range: sema.diagnostics_range(d).range,
             message: d.message(),
             severity: Severity::Error,
             fix: Some(fix),
@@ -95,7 +99,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
         };
 
         res.borrow_mut().push(Diagnostic {
-            range: d.highlight_range(),
+            range: sema.diagnostics_range(d).range,
             message: d.message(),
             severity: Severity::Error,
             fix,
@@ -103,7 +107,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
     })
     .on::<hir::diagnostics::MissingMatchArms, _>(|d| {
         res.borrow_mut().push(Diagnostic {
-            range: d.highlight_range(),
+            range: sema.diagnostics_range(d).range,
             message: d.message(),
             severity: Severity::Error,
             fix: None,
@@ -115,7 +119,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
         let edit = TextEdit::replace(node.syntax().text_range(), replacement);
         let fix = SourceChange::source_file_edit_from("wrap with ok", file_id, edit);
         res.borrow_mut().push(Diagnostic {
-            range: d.highlight_range(),
+            range: sema.diagnostics_range(d).range,
             message: d.message(),
             severity: Severity::Error,
             fix: Some(fix),
@@ -622,6 +626,62 @@ mod tests {
     }
 
     #[test]
+    fn range_mapping_out_of_macros() {
+        let (analysis, file_id) = single_file(
+            r"
+            fn some() {}
+            fn items() {}
+            fn here() {}
+
+            macro_rules! id {
+                ($($tt:tt)*) => { $($tt)*};
+            }
+
+            fn main() {
+                let _x = id![Foo { a: 42 }];
+            }
+
+            pub struct Foo {
+                pub a: i32,
+                pub b: i32,
+            }
+        ",
+        );
+        let diagnostics = analysis.diagnostics(file_id).unwrap();
+        assert_debug_snapshot!(diagnostics, @r###"
+        [
+            Diagnostic {
+                message: "Missing structure fields:\n- b",
+                range: [224; 233),
+                fix: Some(
+                    SourceChange {
+                        label: "fill struct fields",
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                edit: TextEdit {
+                                    atoms: [
+                                        AtomTextEdit {
+                                            delete: [3; 9),
+                                            insert: "{a:42, b: ()}",
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                        file_system_edits: [],
+                        cursor_position: None,
+                    },
+                ),
+                severity: Error,
+            },
+        ]
+        "###);
+    }
+
+    #[test]
     fn test_check_unnecessary_braces_in_use_statement() {
         check_not_applicable(
             "
diff --git a/crates/ra_ide/src/inlay_hints.rs b/crates/ra_ide/src/inlay_hints.rs
index 45b9f7802..0774fa0a1 100644
--- a/crates/ra_ide/src/inlay_hints.rs
+++ b/crates/ra_ide/src/inlay_hints.rs
@@ -237,7 +237,8 @@ fn should_show_param_hint(
 ) -> bool {
     if param_name.is_empty()
         || is_argument_similar_to_param(argument, param_name)
-        || Some(param_name) == fn_signature.name.as_ref().map(String::as_str)
+        || Some(param_name.trim_start_matches('_'))
+            == fn_signature.name.as_ref().map(|s| s.trim_start_matches('_'))
     {
         return false;
     }
@@ -255,6 +256,8 @@ fn should_show_param_hint(
 
 fn is_argument_similar_to_param(argument: &ast::Expr, param_name: &str) -> bool {
     let argument_string = remove_ref(argument.clone()).syntax().to_string();
+    let param_name = param_name.trim_start_matches('_');
+    let argument_string = argument_string.trim_start_matches('_');
     argument_string.starts_with(&param_name) || argument_string.ends_with(&param_name)
 }
 
@@ -1094,8 +1097,10 @@ struct Param {}
 
 fn different_order(param: &Param) {}
 fn different_order_mut(param: &mut Param) {}
+fn has_underscore(_param: bool) {}
 
 fn twiddle(twiddle: bool) {}
+fn doo(_doo: bool) {}
 
 fn main() {
     let container: TestVarContainer = TestVarContainer { test_var: 42 };
@@ -1112,11 +1117,15 @@ fn main() {
     test_processed.frob(false);
 
     twiddle(true);
+    doo(true);
 
     let param_begin: Param = Param {};
     different_order(&param_begin);
     different_order(&mut param_begin);
 
+    let param: bool = true;
+    has_underscore(param);
+
     let a: f64 = 7.0;
     let b: f64 = 4.0;
     let _: f64 = a.div_euclid(b);
diff --git a/crates/ra_ide/src/marks.rs b/crates/ra_ide/src/marks.rs
index 5e1f135c5..eee44e886 100644
--- a/crates/ra_ide/src/marks.rs
+++ b/crates/ra_ide/src/marks.rs
@@ -8,4 +8,5 @@ test_utils::marks!(
     test_resolve_parent_module_on_module_decl
     search_filters_by_range
     dont_insert_macro_call_parens_unncessary
+    self_fulfilling_completion
 );
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index 83d161f45..7b15b82bd 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -174,7 +174,8 @@ pub(crate) fn highlight(
     }
 
     assert_eq!(res.len(), 1, "after DFS traversal, the stack should only contain a single element");
-    let res = res.pop().unwrap();
+    let mut res = res.pop().unwrap();
+    res.sort_by_key(|range| range.range.start());
     // Check that ranges are sorted and disjoint
     assert!(res
         .iter()
diff --git a/crates/ra_ide/src/syntax_highlighting/tests.rs b/crates/ra_ide/src/syntax_highlighting/tests.rs
index 110887c2a..73611e23a 100644
--- a/crates/ra_ide/src/syntax_highlighting/tests.rs
+++ b/crates/ra_ide/src/syntax_highlighting/tests.rs
@@ -156,3 +156,15 @@ fn main() {
     fs::write(dst_file, &actual_html).unwrap();
     assert_eq_text!(expected_html, actual_html);
 }
+
+#[test]
+fn ranges_sorted() {
+    let (analysis, file_id) = single_file(
+        r#"
+#[foo(bar = "bar")]
+macro_rules! test {}
+}"#
+        .trim(),
+    );
+    let _ = analysis.highlight(file_id).unwrap();
+}