Start implementing tests

test/lisp/emacs-lisp/bytecomp-tests.el

@@ -680,6 +680,30 @@ literals (Bug#20852)."
       (should-not (member '(byte-constant 333) lap))
       (should (member '(byte-constant 444) lap)))))
 
+(ert-deftest bytecomp-test--with-suppressed-warnings ()
+  (let ((lexical-binding t)
+        (byte-compile-log-buffer (generate-new-buffer " *Compile-Log*")))
+    (let ((form '(defvar prefixless)))
+      (with-current-buffer byte-compile-log-buffer
+        (let ((inhibit-read-only t))
+          (erase-buffer)))
+      (test-byte-comp-compile-and-load t
+        form)
+      (with-current-buffer byte-compile-log-buffer
+        (goto-char (point-min))
+        (should (re-search-forward "global/dynamic var .prefixless. lacks"
+                                   nil t)))
+      (with-current-buffer byte-compile-log-buffer
+        (let ((inhibit-read-only t))
+          (erase-buffer)))
+      (test-byte-comp-compile-and-load t
+        `(with-suppressed-warnings ((lexical prefixless))
+           ,form))
+      (with-current-buffer byte-compile-log-buffer
+        (goto-char (point-min))
+        (should-not (re-search-forward "global/dynamic var .prefixless. lacks"
+                                       nil t))))))
+
 ;; Local Variables:
 ;; no-byte-compile: t
 ;; End: