1 files changed, 143 insertions, 0 deletions

diff --git a/crates/ra_ide/src/completion/complete_macro_in_item_position.rs b/crates/ra_ide/src/completion/complete_macro_in_item_position.rs
new file mode 100644
index 000000000..faadd1e3f
--- /dev/null
+++ b/crates/ra_ide/src/completion/complete_macro_in_item_position.rs
@@ -0,0 +1,143 @@
+//! FIXME: write short doc here
+
+use crate::completion::{CompletionContext, Completions};
+
+pub(super) fn complete_macro_in_item_position(acc: &mut Completions, ctx: &CompletionContext) {
+    // Show only macros in top level.
+    if ctx.is_new_item {
+        ctx.analyzer.process_all_names(ctx.db, &mut |name, res| {
+            if let hir::ScopeDef::MacroDef(mac) = res {
+                acc.add_macro(ctx, Some(name.to_string()), mac);
+            }
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::completion::{do_completion, CompletionItem, CompletionKind};
+    use insta::assert_debug_snapshot;
+
+    fn do_reference_completion(code: &str) -> Vec<CompletionItem> {
+        do_completion(code, CompletionKind::Reference)
+    }
+
+    #[test]
+    fn completes_macros_as_item() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                "
+                //- /main.rs
+                macro_rules! foo {
+                    () => {}
+                }
+
+                fn foo() {}
+
+                <|>
+                "
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "foo!",
+                source_range: [46; 46),
+                delete: [46; 46),
+                insert: "foo!($0)",
+                kind: Macro,
+                detail: "macro_rules! foo",
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
+    fn completes_vec_macros_with_square_brackets() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                "
+                //- /main.rs
+                /// Creates a [`Vec`] containing the arguments.
+                ///
+                /// - Create a [`Vec`] containing a given list of elements:
+                ///
+                /// ```
+                /// let v = vec![1, 2, 3];
+                /// assert_eq!(v[0], 1);
+                /// assert_eq!(v[1], 2);
+                /// assert_eq!(v[2], 3);
+                /// ```
+                macro_rules! vec {
+                    () => {}
+                }
+
+                fn foo() {}
+
+                <|>
+                "
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "vec!",
+                source_range: [280; 280),
+                delete: [280; 280),
+                insert: "vec![$0]",
+                kind: Macro,
+                detail: "macro_rules! vec",
+                documentation: Documentation(
+                    "Creates a [`Vec`] containing the arguments.\n\n- Create a [`Vec`] containing a given list of elements:\n\n```\nlet v = vec![1, 2, 3];\nassert_eq!(v[0], 1);\nassert_eq!(v[1], 2);\nassert_eq!(v[2], 3);\n```",
+                ),
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
+    fn completes_macros_braces_guessing() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                "
+                //- /main.rs
+                /// Foo
+                ///
+                /// Not call `fooo!()` `fooo!()`, or `_foo![]` `_foo![]`.
+                /// Call as `let _=foo!  { hello world };`
+                macro_rules! foo {
+                    () => {}
+                }
+
+                fn main() {
+                    <|>
+                }
+                "
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "foo!",
+                source_range: [163; 163),
+                delete: [163; 163),
+                insert: "foo! {$0}",
+                kind: Macro,
+                detail: "macro_rules! foo",
+                documentation: Documentation(
+                    "Foo\n\nNot call `fooo!()` `fooo!()`, or `_foo![]` `_foo![]`.\nCall as `let _=foo!  { hello world };`",
+                ),
+            },
+            CompletionItem {
+                label: "main()",
+                source_range: [163; 163),
+                delete: [163; 163),
+                insert: "main()$0",
+                kind: Function,
+                lookup: "main",
+                detail: "fn main()",
+            },
+        ]
+        "###
+        );
+    }
+}