Update nightly only test with #[nightly_only_test] attribute

Author: ytmimi

src/ignore_path.rs

@@ -37,21 +37,17 @@ mod test {
     use crate::config::{Config, FileName};
     use crate::ignore_path::IgnorePathSet;
 
+    use rustfmt_config_proc_macro::nightly_only_test;
+
+    #[nightly_only_test]
     #[test]
     fn test_ignore_path_set() {
-        match option_env!("CFG_RELEASE_CHANNEL") {
-            // this test requires nightly
-            None | Some("nightly") => {
-                let config =
-                    Config::from_toml(r#"ignore = ["foo.rs", "bar_dir/*"]"#, Path::new(""))
-                        .unwrap();
-                let ignore_path_set = IgnorePathSet::from_ignore_list(&config.ignore()).unwrap();
-
-                assert!(ignore_path_set.is_match(&FileName::Real(PathBuf::from("src/foo.rs"))));
-                assert!(ignore_path_set.is_match(&FileName::Real(PathBuf::from("bar_dir/baz.rs"))));
-                assert!(!ignore_path_set.is_match(&FileName::Real(PathBuf::from("src/bar.rs"))));
-            }
-            _ => (),
-        };
+        let config =
+            Config::from_toml(r#"ignore = ["foo.rs", "bar_dir/*"]"#, Path::new("")).unwrap();
+        let ignore_path_set = IgnorePathSet::from_ignore_list(&config.ignore()).unwrap();
+
+        assert!(ignore_path_set.is_match(&FileName::Real(PathBuf::from("src/foo.rs"))));
+        assert!(ignore_path_set.is_match(&FileName::Real(PathBuf::from("bar_dir/baz.rs"))));
+        assert!(!ignore_path_set.is_match(&FileName::Real(PathBuf::from("src/bar.rs"))));
     }
 }