1 files changed, 9 insertions, 0 deletions
diff --git a/src/test/ui/diagnostic-width/flag-json.rs b/src/test/ui/diagnostic-width/flag-json.rs
new file mode 100644
index 000000000..51a1fb447
--- /dev/null
+++ b/src/test/ui/diagnostic-width/flag-json.rs
@@ -0,0 +1,9 @@
+// compile-flags: --diagnostic-width=20 --error-format=json
+
+// This test checks that `-Z output-width` effects the JSON error output by restricting it to an
+// arbitrarily low value so that the effect is visible.
+
+fn main() {
+    let _: () = 42;
+    //~^ ERROR arguments to this function are incorrect
+}