1 files changed, 28 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/check-fmt.rs b/src/tools/clippy/tests/check-fmt.rs
new file mode 100644
index 000000000..0defd45b6
--- /dev/null
+++ b/src/tools/clippy/tests/check-fmt.rs
@@ -0,0 +1,28 @@
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+#![warn(rust_2018_idioms, unused_lifetimes)]
+
+use std::path::PathBuf;
+use std::process::Command;
+
+#[test]
+fn fmt() {
+    if option_env!("RUSTC_TEST_SUITE").is_some() || option_env!("NO_FMT_TEST").is_some() {
+        return;
+    }
+
+    let root_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    let output = Command::new("cargo")
+        .current_dir(root_dir)
+        .args(&["dev", "fmt", "--check"])
+        .output()
+        .unwrap();
+
+    println!("status: {}", output.status);
+    println!("stdout: {}", String::from_utf8_lossy(&output.stdout));
+    println!("stderr: {}", String::from_utf8_lossy(&output.stderr));
+
+    assert!(
+        output.status.success(),
+        "Formatting check failed. Run `cargo dev fmt` to update formatting."
+    );
+}