1 files changed, 25 insertions, 0 deletions
diff --git a/src/test/ui/suggestions/issue-86100-tuple-paren-comma.rs b/src/test/ui/suggestions/issue-86100-tuple-paren-comma.rs
new file mode 100644
index 000000000..fa9d1a889
--- /dev/null
+++ b/src/test/ui/suggestions/issue-86100-tuple-paren-comma.rs
@@ -0,0 +1,25 @@
+// Tests that a suggestion is issued for type mismatch errors when a
+// 1-tuple is expected and a parenthesized expression of non-tuple
+// type is supplied.
+
+fn foo<T>(_t: (T,)) {}
+struct S { _s: (String,) }
+
+fn main() {
+    let _x: (i32,) = (5);
+    //~^ ERROR: mismatched types [E0308]
+    //~| HELP: use a trailing comma to create a tuple with one element
+
+    foo((Some(3)));
+    //~^ ERROR: mismatched types [E0308]
+    //~| HELP: use a trailing comma to create a tuple with one element
+
+    let _s = S { _s: ("abc".to_string()) };
+    //~^ ERROR: mismatched types [E0308]
+    //~| HELP: use a trailing comma to create a tuple with one element
+
+    // Do not issue the suggestion if the found type is already a tuple.
+    let t = (1, 2);
+    let _x: (i32,) = (t);
+    //~^ ERROR: mismatched types [E0308]
+}