1 files changed, 132 insertions, 0 deletions

diff --git a/crates/ra_ide_api/src/completion/complete_record_literal.rs b/crates/ra_ide_api/src/completion/complete_record_literal.rs
new file mode 100644
index 000000000..6b929a8ac
--- /dev/null
+++ b/crates/ra_ide_api/src/completion/complete_record_literal.rs
@@ -0,0 +1,132 @@
+use hir::Substs;
+
+use crate::completion::{CompletionContext, Completions};
+
+/// Complete fields in fields literals.
+pub(super) fn complete_record_literal(acc: &mut Completions, ctx: &CompletionContext) {
+    let (ty, variant) = match ctx.record_lit_syntax.as_ref().and_then(|it| {
+        Some((
+            ctx.analyzer.type_of(ctx.db, &it.clone().into())?,
+            ctx.analyzer.resolve_record_literal(it)?,
+        ))
+    }) {
+        Some(it) => it,
+        _ => return,
+    };
+    let substs = &ty.substs().unwrap_or_else(Substs::empty);
+
+    for field in variant.fields(ctx.db) {
+        acc.add_field(ctx, field, substs);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::completion::{do_completion, CompletionItem, CompletionKind};
+    use insta::assert_debug_snapshot_matches;
+
+    fn complete(code: &str) -> Vec<CompletionItem> {
+        do_completion(code, CompletionKind::Reference)
+    }
+
+    #[test]
+    fn test_record_literal_field() {
+        let completions = complete(
+            r"
+            struct A { the_field: u32 }
+            fn foo() {
+               A { the<|> }
+            }
+            ",
+        );
+        assert_debug_snapshot_matches!(completions, @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "the_field",
+       ⋮        source_range: [83; 86),
+       ⋮        delete: [83; 86),
+       ⋮        insert: "the_field",
+       ⋮        kind: Field,
+       ⋮        detail: "u32",
+       ⋮    },
+       ⋮]
+        "###);
+    }
+
+    #[test]
+    fn test_record_literal_enum_variant() {
+        let completions = complete(
+            r"
+            enum E {
+                A { a: u32 }
+            }
+            fn foo() {
+                let _ = E::A { <|> }
+            }
+            ",
+        );
+        assert_debug_snapshot_matches!(completions, @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "a",
+       ⋮        source_range: [119; 119),
+       ⋮        delete: [119; 119),
+       ⋮        insert: "a",
+       ⋮        kind: Field,
+       ⋮        detail: "u32",
+       ⋮    },
+       ⋮]
+        "###);
+    }
+
+    #[test]
+    fn test_record_literal_two_structs() {
+        let completions = complete(
+            r"
+            struct A { a: u32 }
+            struct B { b: u32 }
+
+            fn foo() {
+               let _: A = B { <|> }
+            }
+            ",
+        );
+        assert_debug_snapshot_matches!(completions, @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "b",
+       ⋮        source_range: [119; 119),
+       ⋮        delete: [119; 119),
+       ⋮        insert: "b",
+       ⋮        kind: Field,
+       ⋮        detail: "u32",
+       ⋮    },
+       ⋮]
+        "###);
+    }
+
+    #[test]
+    fn test_record_literal_generic_struct() {
+        let completions = complete(
+            r"
+            struct A<T> { a: T }
+
+            fn foo() {
+               let _: A<u32> = A { <|> }
+            }
+            ",
+        );
+        assert_debug_snapshot_matches!(completions, @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "a",
+       ⋮        source_range: [93; 93),
+       ⋮        delete: [93; 93),
+       ⋮        insert: "a",
+       ⋮        kind: Field,
+       ⋮        detail: "u32",
+       ⋮    },
+       ⋮]
+        "###);
+    }
+}