Merge #4377

4377: Implement better handling of divergence r=matklad a=flodiebold

Divergence here means that for some reason, the end of a block will not be reached. We tried to model this just using the never type, but that doesn't work fully (e.g. in `let x = { loop {}; "foo" };` x should still have type `&str`); so this introduces a `diverges` flag that the type checker keeps track of, like rustc does. We also add some checking for `break`, but no support for break-with-value or labeled breaks yet.

Co-authored-by: Florian Diebold <[email protected]>
Co-authored-by: Florian Diebold <[email protected]>

1 files changed, 18 insertions, 0 deletions

diff --git a/crates/ra_hir_ty/src/tests.rs b/crates/ra_hir_ty/src/tests.rs
index d60732e19..5af88b368 100644
--- a/crates/ra_hir_ty/src/tests.rs
+++ b/crates/ra_hir_ty/src/tests.rs
@@ -518,3 +518,21 @@ fn missing_record_pat_field_no_diagnostic_if_not_exhaustive() {
 
     assert_snapshot!(diagnostics, @"");
 }
+
+#[test]
+fn break_outside_of_loop() {
+    let diagnostics = TestDB::with_files(
+        r"
+        //- /lib.rs
+        fn foo() {
+            break;
+        }
+        ",
+    )
+    .diagnostics()
+    .0;
+
+    assert_snapshot!(diagnostics, @r###""break": break outside of loop
+    "###
+    );
+}