fix(slugger): fix slugger crash due to title property

the slugger would assume `title` to always be a `string`, which was an invalid assumption for
objects that have a `title` property declaration

fixes #196

lib/schemaProxy.js

@@ -54,7 +54,10 @@ const handler = ({
       return [...parent[symbols.titles], target.title];
     }
     // otherwise, it's just our own
-    return [target[keyword`title`]];
+    if (typeof target.title === 'string') {
+      return [target[keyword`title`]];
+    }
+    return [];
   };
 
   meta[symbols.resolve] = (target, prop, receiver) => (path) => {
@@ -80,8 +83,13 @@ const handler = ({
       const parentslug = parent[symbols.slug];
       const { title } = receiver;
       const name = receiver[symbols.pointer].split('/').pop();
-      // eslint-disable-next-line no-param-reassign
-      receiver[myslug] = slugger.slug(`${parentslug}-${title || name}`);
+      if (typeof title === 'string') {
+        // eslint-disable-next-line no-param-reassign
+        receiver[myslug] = slugger.slug(`${parentslug}-${title || name}`);
+      } else {
+        // eslint-disable-next-line no-param-reassign
+        receiver[myslug] = slugger.slug(`${parentslug}-${name}`);
+      }
     }
     return receiver[myslug];
   };

test/markdownBuilder.test.js

@@ -72,14 +72,8 @@ describe('Testing Markdown Builder: title', () => {
   });
 
   it('Meta Schema looks OK', () => {
-    assertMarkdown(results.title)
-      .fuzzy`## Not true Type
-
-merged type ([Not true](not.md))
-
-not
-
--   [True](not-true.md "check type definition")`;
+    assertMarkdown(results.meta)
+      .fuzzy`defined in: [Meta](meta-definitions-meta-properties-title.md "https://ns.adobe.com/helix/pipeline/meta#/definitions/meta/properties/title")`;
   });
 });