test/expand_test.clj

@@ -46,6 +46,9 @@
 (defn- us-expand [datum]
   (sut/unscope (sut/expand datum)))
 
+(defn- rg-expand [datum]
+  (sut/regensym (sut/expand datum)))
+
 (t/deftest expand-test
   (t/testing "unbound symbol"
     (t/is (thrown? Exception (sut/expand 'x))))
@@ -53,11 +56,11 @@
     (t/is (= '(lambda (x) x)
              (us-expand '(λ (x) x)))))
   #_(t/testing "syntax-rules"
-    (t/is (= '(lambda (x) x)
-             (sut/expand
-              '(syntax-rules
-                ()
-                ((_)))))))
+      (t/is (= '(lambda (x) x)
+               (sut/expand
+                '(syntax-rules
+                  ()
+                  ((_)))))))
   (t/testing "let"
     (t/is (= '(let ((x 123)
                     (y 456))
@@ -68,7 +71,18 @@
                  (+ x y))))))
   (t/testing "application"
     (t/is (= '(lambda (f x) (f x))
-             (us-expand '(lambda (f x) (f x)))))))
+             (us-expand '(lambda (f x) (f x))))))
+  (t/testing "macros"
+    (t/testing "when"
+      (t/is (= '(let ((x 123)) (if x 456))
+               (us-expand '(let ((x 123))
+                             (when x 456)))))
+      (t/is (= '(let (([body #{s0}] 123))
+                  (if [body #{s0}]
+                    456))
+               (rg-expand '(let ((body 123))
+                             (when body 456))))
+            "`when` is hygienic"))))
 
 (t/deftest prim-lambda-spec
   (t/is (s/valid? ::sut/prim-lambda '(lambda (x) x)))