coverage: Branch coverage test for let-else

1 files changed, 35 insertions, 0 deletions

diff --git a/tests/coverage/branch/let-else.rs b/tests/coverage/branch/let-else.rs
new file mode 100644
index 00000000000..af0665d8241
--- /dev/null
+++ b/tests/coverage/branch/let-else.rs
@@ -0,0 +1,35 @@
+#![feature(coverage_attribute)]
+//@ edition: 2021
+//@ compile-flags: -Zcoverage-options=branch
+//@ llvm-cov-flags: --show-branches=count
+
+macro_rules! no_merge {
+    () => {
+        for _ in 0..1 {}
+    };
+}
+
+fn let_else(value: Option<&str>) {
+    no_merge!();
+
+    let Some(x) = value else {
+        say("none");
+        return;
+    };
+
+    say(x);
+}
+
+#[coverage(off)]
+fn say(message: &str) {
+    core::hint::black_box(message);
+}
+
+#[coverage(off)]
+fn main() {
+    let_else(Some("x"));
+    let_else(Some("x"));
+    let_else(None);
+}
+
+// FIXME(#124118) Actually instrument let-else for branch coverage.