Syntax: Add highlithing for YAML metadata block (#1287)

test/issue_1287_yaml_header.vader

@@ -0,0 +1,95 @@
+# Non regression tests for issue: #1287
+
+
+Before(Define function for yaml inspection):
+  function! Issue1287Yaml(line)
+    " The line where the yaml delimiter is: 1 if at top
+    let l = a:line
+    AssertEqual 'textSnipYAML', GetSyntaxStack(l + 0, 2)[0]
+    AssertEqual 'VimwikiPre', GetSyntaxStack(l + 0, 2)[1]
+
+    AssertEqual 'textSnipYAML', GetSyntaxStack(l + 1, 2)[0]
+    AssertEqual 'textSnipYAML', GetSyntaxStack(l + 2, 2)[0]
+    AssertEqual 'textSnipYAML', GetSyntaxStack(l + 2, 20)[0]
+
+    AssertEqual 'VimwikiPre', GetSyntaxStack(l + 3, 2)[-1]
+  endfunction
+
+
+Given vimwiki (Yaml with --- at top):
+  ---
+  title: my title
+  description: my description
+  ---
+
+Execute (Assert delimiter with --- at top):
+  call Issue1287Yaml(1)
+
+Given vimwiki (Yaml with ... at top):
+  ...
+  title: my title
+  description: my description
+  ...
+
+Execute (Assert delimiter with ... at top):
+  call Issue1287Yaml(1)
+
+Given vimwiki (Yaml with --- after empty line):
+  A stupid block
+  of 2 lines
+  
+  ---
+  title: my title
+  description: my description
+  ---
+
+Execute (Assert delimiter with --- after empty line):
+  call Issue1287Yaml(4)
+
+
+Given vimwiki (Yaml with --- mixed with ...):
+  ---
+  title: my title
+  ...
+  comment: my comment
+  description: my description
+  ---
+  
+  And a text follows
+
+Execute (Assert all is yaml except after the closing ---):
+  AssertEqual 'textSnipYAML1', GetSyntaxStack(1, 2)[0] . 1
+  AssertEqual 'VimwikiPre1', GetSyntaxStack(1, 2)[1] . 1
+
+  AssertEqual 'textSnipYAML1', GetSyntaxStack(1, 2)[0] . 1
+  AssertEqual 'textSnipYAML2', GetSyntaxStack(2, 2)[0] . 2
+  AssertEqual 'textSnipYAML3', GetSyntaxStack(3, 2)[0] . 3
+  AssertEqual 'textSnipYAML4', GetSyntaxStack(4, 2)[0] . 4
+  AssertEqual 'textSnipYAML5', GetSyntaxStack(5, 2)[0] . 5
+  AssertEqual 'textSnipYAML6', GetSyntaxStack(5, 2)[0] . 6
+
+  AssertEqual 0, len(GetSyntaxStack(7, 2))
+  AssertEqual 0, len(GetSyntaxStack(8, 2))
+
+
+Given vimwiki (Yaml with --- with a --- not a start of line):
+  ---
+  title: my title
+  comment: my comment ---
+  description: my description
+  ---
+  
+  And a text follows
+
+Execute (Assert all is yaml except after the closing ---):
+  AssertEqual 'textSnipYAML1', GetSyntaxStack(1, 2)[0] . 1
+  AssertEqual 'VimwikiPre1', GetSyntaxStack(1, 2)[1] . 1
+
+  AssertEqual 'textSnipYAML1', GetSyntaxStack(1, 2)[0] . 1
+  AssertEqual 'textSnipYAML2', GetSyntaxStack(2, 2)[0] . 2
+  AssertEqual 'textSnipYAML3', GetSyntaxStack(3, 2)[0] . 3
+  AssertEqual 'textSnipYAML4', GetSyntaxStack(4, 2)[0] . 4
+  AssertEqual 'VimwikiPre5', GetSyntaxStack(5, 2)[-1] . 5
+
+  AssertEqual 0, len(GetSyntaxStack(6, 2))
+  AssertEqual 0, len(GetSyntaxStack(7, 2))

test/vimrc

@@ -343,21 +343,37 @@
     0d
   endfunction
 
-  function! GetSyntaxGroup(line, col)
+  function! GetSyntaxGroup(...)
     " Get normalized syntax group: usefull for boldItalic Vs italicBold
+    " Arg1: line
+    " Arg2: column
     " -- Here, Vader's SyntaxAt is not enough
     " From: https://stackoverflow.com/questions/9464844
-    let l:s = synID(a:line, a:col, 1)
+    let line = a:0 >= 1 ? a:1 : '.'
+    let col = a:0 >= 2 ? a:2 : '.'
+
+    let l:s = synID(line, col, 1)
     return synIDattr(synIDtrans(l:s), 'name')
   endfun
 
-  function! GetSyntaxStack()
+  function! GetSyntaxStack(...)
     " Debug helper
+    " Arg1: line
+    " Arg2: column
+    let line = a:0 >= 1 ? a:1 : '.'
+    let col = a:0 >= 2 ? a:2 : '.'
     if !exists('*synstack')
-      return
+      return []
     endif
-    return map(synstack(line('.'), col('.')), 'synIDattr(v:val, "name")')
-  endfunc
+    let res = map(synstack(line, col), 'synIDattr(v:val, "name")')
+
+    " For old vim version returning 0
+    if type(res) == type(0) && res == 0
+      return []
+    endif
+
+    return res
+  endfunction
 
   function! AssertIfVersion(version, one, two)
     " Run Assert only if vim version is high enough