feat: add testing macros and unit tests for linters

Add `assert_detected!` and `assert_not_detected!` macros to simplify
writing lint tests, along with initial test coverage for the
unnecessary render result creation linter.

1 files changed, 18 insertions, 0 deletions

diff --git a/mingling_cli/tmpls/lints.tmpl b/mingling_cli/tmpls/lints.tmpl
index 7507f98..fae1126 100644
--- a/mingling_cli/tmpls/lints.tmpl
+++ b/mingling_cli/tmpls/lints.tmpl
@@ -50,6 +50,24 @@ pub fn run_all_lints(file: &syn::File, source: &str) -> Vec<MlintReport> {
     reports
 }
 
+#[macro_export]
+macro_rules! assert_detected {
+    ($linter:expr, $ast_type:ty => $code:tt) => {
+        // Parse the string into a syn::ItemFn
+        let ast: $ast_type = syn::parse_str(&stringify!($code)).unwrap();
+        assert!(!$linter(ast, &stringify!($code).to_string()).is_empty());
+    };
+}
+
+#[macro_export]
+macro_rules! assert_not_detected {
+    ($linter:expr, $ast_type:ty => $code:tt) => {
+        // Parse the string into a syn::ItemFn
+        let ast: $ast_type = syn::parse_str(&stringify!($code)).unwrap();
+        assert!($linter(ast, &stringify!($code).to_string()).is_empty());
+    };
+}
+
 @@@ >>> impls
 mod <<<mod_name>>>;
 pub use <<<mod_name>>>::linter as <<<mod_name>>>;