Merge #3905

3905: add ellipsis field to hir pat record r=matklad a=JoshMcguigan

This PR corrects a `fixme`, adding an `ellipsis` field to the hir `Pat::Record` type. It will also be unlock some useful follow on work for #3894.

Additionally it adds a diagnostic for missing fields in record patterns.

~~Marking as a draft because I don't have any tests, and a small amount of manual testing on my branch from #3894 suggests it might *not* be working. Any thoughts on how I can best test this, or else pointers on where I might be going wrong?~~

Co-authored-by: Josh Mcguigan <[email protected]>

1 files changed, 40 insertions, 0 deletions

diff --git a/crates/ra_hir_ty/src/tests.rs b/crates/ra_hir_ty/src/tests.rs
index 002cffba6..47a7b9ffd 100644
--- a/crates/ra_hir_ty/src/tests.rs
+++ b/crates/ra_hir_ty/src/tests.rs
@@ -409,3 +409,43 @@ fn no_such_field_with_feature_flag_diagnostics_on_struct_fields() {
 
     assert_snapshot!(diagnostics, @r###""###);
 }
+
+#[test]
+fn missing_record_pat_field_diagnostic() {
+    let diagnostics = TestDB::with_files(
+        r"
+        //- /lib.rs
+        struct S { foo: i32, bar: () }
+        fn baz(s: S) {
+            let S { foo: _ } = s;
+        }
+        ",
+    )
+    .diagnostics()
+    .0;
+
+    assert_snapshot!(diagnostics, @r###"
+    "{ foo: _ }": Missing structure fields:
+    - bar
+    "###
+    );
+}
+
+#[test]
+fn missing_record_pat_field_no_diagnostic_if_not_exhaustive() {
+    let diagnostics = TestDB::with_files(
+        r"
+        //- /lib.rs
+        struct S { foo: i32, bar: () }
+        fn baz(s: S) -> i32 {
+            match s {
+                S { foo, .. } => foo,
+            }
+        }
+        ",
+    )
+    .diagnostics()
+    .0;
+
+    assert_snapshot!(diagnostics, @"");
+}