coverage: Branch coverage test for if-let and let-chains

1 files changed, 58 insertions, 0 deletions

diff --git a/tests/coverage/branch/if-let.rs b/tests/coverage/branch/if-let.rs
new file mode 100644
index 00000000000..13db00a82b1
--- /dev/null
+++ b/tests/coverage/branch/if-let.rs
@@ -0,0 +1,58 @@
+#![feature(coverage_attribute, let_chains)]
+//@ edition: 2021
+//@ compile-flags: -Zcoverage-options=branch
+//@ llvm-cov-flags: --show-branches=count
+
+macro_rules! no_merge {
+    () => {
+        for _ in 0..1 {}
+    };
+}
+
+fn if_let(input: Option<&str>) {
+    no_merge!();
+
+    if let Some(x) = input {
+        say(x);
+    } else {
+        say("none");
+    }
+    say("done");
+}
+
+fn if_let_chain(a: Option<&str>, b: Option<&str>) {
+    if let Some(x) = a
+        && let Some(y) = b
+    {
+        say(x);
+        say(y);
+    } else {
+        say("not both");
+    }
+    say("done");
+}
+
+#[coverage(off)]
+fn say(message: &str) {
+    core::hint::black_box(message);
+}
+
+#[coverage(off)]
+fn main() {
+    if_let(Some("x"));
+    if_let(Some("x"));
+    if_let(None);
+
+    for _ in 0..8 {
+        if_let_chain(Some("a"), Some("b"));
+    }
+    for _ in 0..4 {
+        if_let_chain(Some("a"), None);
+    }
+    for _ in 0..2 {
+        if_let_chain(None, Some("b"));
+    }
+    if_let_chain(None, None);
+}
+
+// FIXME(#124118) Actually instrument if-let and let-chains for branch coverage.