Allow markdown syntax to have tags at top of file.

Previously tags that did not fall under a header caused errors because
the generation code expected an anchor.

Update tags test case.

Closes #790

autoload/vimwiki/tags.vim

@@ -354,15 +354,17 @@ function! vimwiki#tags#generate_tags(create, ...) abort
             let link_tpl = vimwiki#vars#get_syntaxlocal('Weblink3Template')
             let link_infos = vimwiki#base#resolve_link(taglink)
             if empty(link_infos.anchor)
-              echom 'Vimwiki Error: Tags must appear after a header.'
+              let link_tpl = vimwiki#vars#get_syntaxlocal('Weblink1Template')
-              return []
+              let entry = s:safesubstitute(link_tpl, '__LinkUrl__', taglink, '')
-            endif
+              let entry = s:safesubstitute(entry, '__LinkDescription__', taglink, '')
+            else
               let link_caption = split(link_infos.anchor, '#', 0)[-1]
               let link_text = split(taglink, '#', 1)[0]
-
               let entry = s:safesubstitute(link_tpl, '__LinkUrl__', link_text, '')
               let entry = s:safesubstitute(entry, '__LinkAnchor__', link_infos.anchor, '')
               let entry = s:safesubstitute(entry, '__LinkDescription__', link_caption, '')
+            endif
+
             call add(lines, bullet . entry)
           else
             let link_tpl = vimwiki#vars#get_global('WikiLinkTemplate1')

test/command_generate_tags.vader

@@ -1,67 +1,90 @@
 Include: vader_includes/vader_setup.vader
 
-
 Execute (Copy Wiki's Resources):
   Log "Start: Copy Resources"
   call CopyResources()
 
-
+Execute (Setup):
-# 1 VimwikiRebuildTags
-######################
-
-Execute (New Command):
-  Log "1 Testing VimwikiRebuildTags"
   set sw=4
   AssertEqual 4, &sw
 
-
 Execute (Edit Test-Tag.md):
   edit $HOME/testmarkdown/Test-Tag.md
   AssertEqual $HOME . '/testmarkdown/Test-Tag.md', expand('%')
   AssertEqual 'markdown', vimwiki#vars#get_wikilocal('syntax')
   AssertEqual 1, vimwiki#vars#get_bufferlocal('wiki_nr')
 
-Do (Add tag <- with `Do` trick to save file):
+Do (Create File Content):
   :edit $HOME/testmarkdown/Test-Tag.md\<CR>
-  :call append(0, ":test-tag:")\<CR>
+  I
-  :set bt=\<CR>
+  :top-tag:\<CR>
-  :write %\<CR>
+  \<CR>
+  # A header\<CR>
+  \<CR>
+  :test-tag:\<CR>
+  \<CR>
+  # Another header\<CR>
+  \<CR>
+  Words here.\<CR>
+  If tag isn't within 2 lines of header then it has a direct link instead of\<CR>
+  a link to the header.\<CR>
+  \<CR>
+  :second-tag:
+  \<Esc>
+  :write\<CR>
   :VimwikiRebuildTags\<CR>
 
-Execute (Edit .vimwiki_tags):
+Execute (Edit tags file):
   edit $HOME/testmarkdown/.vimwiki_tags
   AssertEqual $HOME . '/testmarkdown/.vimwiki_tags', expand('%')
   AssertEqual 'markdown', vimwiki#vars#get_wikilocal('syntax')
   AssertEqual 1, vimwiki#vars#get_bufferlocal('wiki_nr')
 
-# Carefull, following 2 lines have tabs: `this is the way`
+# Note: tags file uses tabs
-Expect (Tag file with test-tag):
+Expect (Correctly formatted tags file):
+  !_TAG_FILE_FORMAT	2
   !_TAG_FILE_SORTED	1
-  test-tag	Test-Tag.md	1;"	vimwiki:Test-Tag\tTest-Tag
+  !_TAG_OUTPUT_MODE	vimwiki-tags
+  !_TAG_PROGRAM_AUTHOR	Vimwiki
+  !_TAG_PROGRAM_NAME	Vimwiki Tags
+  !_TAG_PROGRAM_URL	https://github.com/vimwiki/vimwiki
+  !_TAG_PROGRAM_VERSION	2.4.1
+  second-tag	Test-Tag.md	13;"	vimwiki:Test-Tag\tTest-Tag#second-tag
+  test-tag	Test-Tag.md	5;"	vimwiki:Test-Tag\tTest-Tag#A header
+  top-tag	Test-Tag.md	1;"	vimwiki:Test-Tag\tTest-Tag
 
+Execute (Generate tags):
+  edit $HOME/testmarkdown/Test-Tag.md
+  VimwikiGenerateTags
 
-# 2 VimwikiGenerateTags
+Expect (Correctly generated tags section):
-#########################
+  :top-tag:
 
-Execute (New Command):
+  # A header
-  Log "2 Testing VimwikiGenerateTags TODO"
-  set sw=4
-  AssertEqual 4, &sw
 
-Given (Void):
+  :test-tag:
 
-Do (Edit Test-Tag && GenerateTags):
+  # Another header
-  :edit $HOME/testmarkdown/Test-Tag.md\<CR>
-  :call append(0, ':Tag:')\<Cr>
-  :call append(0, '')\<Cr>
-  :call append(0, 'Test Here')\<Cr>
-  :call append(0, '')\<Cr>
-  :call append(0, '# A header')\<Cr>
-  :call WriteMe()\<CR>
-  :VimwikiRebuildTags\<CR>
-  :VimwikiGenerateTags\<CR>
-  :Log "TODO give the expect block when VimwikigenerateTags is working"\<CR>
 
+  Words here.
+  If tag isn't within 2 lines of header then it has a direct link instead of
+  a link to the header.
+
+  :second-tag:
+
+  # Generated Tags
+
+  ## second-tag
+
+  - [second-tag](Test-Tag#second-tag)
+
+  ## test-tag
+
+  - [A header](Test-Tag#A header)
+
+  ## top-tag
+
+  - [Test-Tag](Test-Tag)
 
 Execute (Clean Test-Tag and .vimwiki_tags):
   Log "End: Clean"
@@ -70,6 +93,4 @@ Execute (Clean Test-Tag and .vimwiki_tags):
   call system("rm $HOME/testmarkdown/Test-Tag.md")
   call DeleteHiddenBuffers()
 
-
 Include: vader_includes/vader_teardown.vader
-# vim: sw=2 foldmethod=indent foldlevel=30 foldignore=