Add test case for titles

Author: bame-da

tests/_toc_files/basic.yml

@@ -6,6 +6,7 @@ subtrees:
     numbered: true
     entries:
     - file: doc1
+      title: "custom"
     - file: doc2
     - file: doc3
       subtrees:

tests/test_parsing/test_create_toc_dict_basic_.yml

@@ -1,5 +1,6 @@
 entries:
 - file: doc1
+  title: custom
 - file: doc2
 - entries:
   - file: subfolder/doc4

tests/test_parsing/test_file_to_sitemap_basic_.yml

@@ -2,7 +2,7 @@ documents:
   doc1:
     docname: doc1
     subtrees: []
-    title: null
+    title: custom
   doc2:
     docname: doc2
     subtrees: []
@@ -29,7 +29,7 @@ documents:
       hidden: true
       items:
       - path: doc1
-        title: null
+        title: custom
       - path: doc2
         title: null
       - path: doc3

tests/test_sphinx/test_success_basic_.xml

@@ -3,4 +3,4 @@
         <title>
             Heading: intro.rst
         <compound classes="toctree-wrapper">
-            <toctree caption="Part Caption" entries="(None,\ 'doc1') (None,\ 'doc2') (None,\ 'doc3')" glob="False" hidden="True" includefiles="doc1 doc2 doc3" includehidden="False" maxdepth="-1" numbered="999" parent="intro" rawcaption="Part Caption" titlesonly="True">
+            <toctree caption="Part Caption" entries="('custom',\ 'doc1') (None,\ 'doc2') (None,\ 'doc3')" glob="False" hidden="True" includefiles="doc1 doc2 doc3" includehidden="False" maxdepth="-1" numbered="999" parent="intro" rawcaption="Part Caption" titlesonly="True">