1 files changed, 93 insertions, 0 deletions

diff --git a/crates/ra_ide/src/completion/complete_record_pattern.rs b/crates/ra_ide/src/completion/complete_record_pattern.rs
new file mode 100644
index 000000000..a56c7e3a1
--- /dev/null
+++ b/crates/ra_ide/src/completion/complete_record_pattern.rs
@@ -0,0 +1,93 @@
+//! FIXME: write short doc here
+
+use crate::completion::{CompletionContext, Completions};
+
+pub(super) fn complete_record_pattern(acc: &mut Completions, ctx: &CompletionContext) {
+    let (ty, variant) = match ctx.record_lit_pat.as_ref().and_then(|it| {
+        Some((
+            ctx.analyzer.type_of_pat(ctx.db, &it.clone().into())?,
+            ctx.analyzer.resolve_record_pattern(it)?,
+        ))
+    }) {
+        Some(it) => it,
+        _ => return,
+    };
+
+    for (field, field_ty) in ty.variant_fields(ctx.db, variant) {
+        acc.add_field(ctx, field, &field_ty);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::completion::{do_completion, CompletionItem, CompletionKind};
+    use insta::assert_debug_snapshot;
+
+    fn complete(code: &str) -> Vec<CompletionItem> {
+        do_completion(code, CompletionKind::Reference)
+    }
+
+    #[test]
+    fn test_record_pattern_field() {
+        let completions = complete(
+            r"
+            struct S { foo: u32 }
+
+            fn process(f: S) {
+                match f {
+                    S { f<|>: 92 } => (),
+                }
+            }
+            ",
+        );
+        assert_debug_snapshot!(completions, @r###"
+        [
+            CompletionItem {
+                label: "foo",
+                source_range: [117; 118),
+                delete: [117; 118),
+                insert: "foo",
+                kind: Field,
+                detail: "u32",
+            },
+        ]
+        "###);
+    }
+
+    #[test]
+    fn test_record_pattern_enum_variant() {
+        let completions = complete(
+            r"
+            enum E {
+                S { foo: u32, bar: () }
+            }
+
+            fn process(e: E) {
+                match e {
+                    E::S { <|> } => (),
+                }
+            }
+            ",
+        );
+        assert_debug_snapshot!(completions, @r###"
+        [
+            CompletionItem {
+                label: "bar",
+                source_range: [161; 161),
+                delete: [161; 161),
+                insert: "bar",
+                kind: Field,
+                detail: "()",
+            },
+            CompletionItem {
+                label: "foo",
+                source_range: [161; 161),
+                delete: [161; 161),
+                insert: "foo",
+                kind: Field,
+                detail: "u32",
+            },
+        ]
+        "###);
+    }
+}