add tests for possible issue. see tobiipro/minlog#28

Author: andreineculau

test/minlog.test.js

@@ -123,6 +123,12 @@ describe('minlog', function() {
         expect(upperLevelCode).toBe(vanillaLevelCode);
       });
     });
+
+    it('should throw if level is unknown', function() {
+      expect(function() {
+        logger.levelToLevelCode('unknown');
+      }).toThrow(/^Unknown level name unknown./);
+    });
   });
 
   describe('levelToLevelName', function() {
@@ -149,6 +155,12 @@ describe('minlog', function() {
         expect(levelName).toBe(`lvl${level}`);
       });
     });
+
+    it('should throw if level is unknown', function() {
+      expect(function() {
+        logger.levelToLevelName('unknown');
+      }).toThrow(/^Unknown level name unknown./);
+    });
   });
 
   describe('maxLevelCodeInGroup', function() {