Given markdown;
a **b** c

Execute (bold):
  AssertNotEqual SyntaxOf('a'), 'htmlBold'
  AssertEqual SyntaxOf('b'), 'htmlBold'
  AssertNotEqual SyntaxOf('c'), 'htmlBold'

Given markdown;
a __b__ c

Execute (bold):
  AssertNotEqual SyntaxOf('a'), 'htmlBold'
  AssertEqual SyntaxOf('b'), 'htmlBold'
  AssertNotEqual SyntaxOf('c'), 'htmlBold'

Given markdown;
a *b* c

Execute (italic):
  AssertNotEqual SyntaxOf('a'), 'htmlItalic'
  AssertEqual SyntaxOf('b'), 'htmlItalic'
  AssertNotEqual SyntaxOf('c'), 'htmlItalic'

Given markdown;
a _b_ c

Execute (italic):
  AssertNotEqual SyntaxOf('a'), 'htmlItalic'
  AssertEqual SyntaxOf('b'), 'htmlItalic'
  AssertNotEqual SyntaxOf('c'), 'htmlItalic'

Given markdown;
a \*b\* c

Execute (not italic with escaped asterisks):
  AssertNotEqual SyntaxOf('a'), 'htmlItalic'
  AssertNotEqual SyntaxOf('b'), 'htmlItalic'
  AssertNotEqual SyntaxOf('c'), 'htmlItalic'

Given markdown;
a \_b\_ c

Execute (not italic with escaped underscores):
  AssertNotEqual SyntaxOf('a'), 'htmlItalic'
  AssertNotEqual SyntaxOf('b'), 'htmlItalic'
  AssertNotEqual SyntaxOf('c'), 'htmlItalic'

Given markdown;
a _b\_c_ d

Execute (italic with escaped underscores):
  AssertNotEqual SyntaxOf('a'), 'htmlItalic'
  AssertEqual SyntaxOf('b'), 'htmlItalic'
  AssertEqual SyntaxOf('c'), 'htmlItalic'
  AssertNotEqual SyntaxOf('d'), 'htmlItalic'

Given markdown;
a __b\_\_c__ d

Execute (bold with escaped underscores):
  AssertNotEqual SyntaxOf('a'), 'htmlBold'
  AssertEqual SyntaxOf('b'), 'htmlBold'
  AssertEqual SyntaxOf('c'), 'htmlBold'
  AssertNotEqual SyntaxOf('d'), 'htmlBold'

# Links

Given markdown;
[a](b)

Execute (link with title):
  AssertEqual SyntaxOf('a'), 'mkdLink'
  AssertEqual SyntaxOf('b'), 'mkdURL'

Given markdown;
(a)

(b)

Execute (parenthesis not in link):
  AssertNotEqual SyntaxOf('a'), 'mkdURL'
  AssertNotEqual SyntaxOf('b'), 'mkdURL'

Given markdown;
[a](b) c [d](e)

Execute (multiple links on a line):
  AssertEqual SyntaxOf('c'), ''

# Autolinks

Given markdown;
a <http://b> c

Execute (autolink):
  AssertNotEqual SyntaxOf('a'), 'mkdInlineURL'
  AssertEqual SyntaxOf('<'), 'mkdDelimiter'
  AssertEqual SyntaxOf('b'), 'mkdInlineURL'
  AssertEqual SyntaxOf('>'), 'mkdDelimiter'
  AssertNotEqual SyntaxOf('c'), 'mkdInlineURL'

Given markdown;
<HtTp://a>

Execute (autolink with scheme case is insensitive):
  AssertEqual SyntaxOf('a'), 'mkdInlineURL'

Given markdown;
<notascheme://a>

Execute (autolink without known scheme is not a link):
  AssertNotEqual SyntaxOf('n'), 'mkdInlineURL'

Given markdown;
<a>

Execute (autolink without scheme is not a link):
  AssertNotEqual SyntaxOf('a'), 'mkdInlineURL'

Given markdown;
< http://a >
<http://b c>
<http://d
e>

Execute (autolink with space is not a link):
  AssertNotEqual SyntaxOf('a'), 'mkdInlineURL'
  AssertNotEqual SyntaxOf('b'), 'mkdInlineURL'
  AssertNotEqual SyntaxOf('c'), 'mkdInlineURL'
  AssertNotEqual SyntaxOf('d'), 'mkdInlineURL'
  AssertNotEqual SyntaxOf('e'), 'mkdInlineURL'

Given markdown;
\<http://a>

Execute (autolinks can be backslash escaped):
  AssertNotEqual SyntaxOf('<'), 'mkdDelimiter'

Given markdown;
a (http://b) c

Execute (autolink in parenthesis):
  AssertNotEqual SyntaxOf('a'), 'mkdInlineURL'
  AssertEqual SyntaxOf('('), 'mkdDelimiter'
  AssertEqual SyntaxOf('b'), 'mkdInlineURL'
  AssertEqual SyntaxOf(')'), 'mkdDelimiter'
  AssertNotEqual SyntaxOf('c'), 'mkdInlineURL'

Given markdown;
[![a](http://b)](http://c)

Execute (autolink in link text):
  AssertEqual SyntaxOf('!'), 'mkdDelimiter'
  AssertEqual SyntaxOf('a'), 'mkdLink'
  AssertEqual SyntaxOf('b'), 'mkdURL'
  AssertEqual SyntaxOf('c'), 'mkdURL'

# Code Blocks

Given markdown;
~~~
code
~~~

Execute (code blocks can be fenced with tildes):
  AssertEqual SyntaxOf('c'), 'mkdCode'

Given markdown;
~~~ruby
code
~~~

Execute (code blocks can have a language specifier):
  AssertEqual SyntaxOf('c'), 'mkdCode'

Given markdown;
```c++
code
```

text

Execute (code blocks can be fenced with backticks and a language specifier):
  AssertEqual SyntaxOf('code'), 'mkdCode'
  AssertNotEqual SyntaxOf('text'), 'mkdCode'

# Math

Given markdown;
a $x$ b
c $$y$$ d
\$e\$
\$\$f\$\$

Execute (math):
  AssertNotEqual SyntaxOf('x'), 'mkdMath'
  AssertNotEqual SyntaxOf('y'), 'mkdMath'
  let g:vim_markdown_math=1
  syn off | syn on
  AssertNotEqual SyntaxOf('a'), 'mkdMath'
  AssertNotEqual SyntaxOf('b'), 'mkdMath'
  AssertNotEqual SyntaxOf('c'), 'mkdMath'
  AssertNotEqual SyntaxOf('d'), 'mkdMath'
  AssertNotEqual SyntaxOf('e'), 'mkdMath'
  AssertNotEqual SyntaxOf('f'), 'mkdMath'
  AssertEqual SyntaxOf('x'), 'mkdMath'
  AssertEqual SyntaxOf('y'), 'mkdMath'
  let g:vim_markdown_math=0
  syn off | syn on
  AssertNotEqual SyntaxOf('x'), 'mkdMath'
  AssertNotEqual SyntaxOf('y'), 'mkdMath'

Given markdown;
a

$
b
$

c

Execute (multiline math):
  let g:vim_markdown_math=1
  syn off | syn on
  AssertNotEqual SyntaxOf('a'), 'mkdMath'
  AssertEqual SyntaxOf('b'), 'mkdMath'
  AssertNotEqual SyntaxOf('c'), 'mkdMath'

Given markdown;
$ \sqrt{a}{b} $
$$ \frac{a}{b} $$

Execute (math tex highlighting):
  let g:vim_markdown_math=0
  syn off | syn on
  AssertNotEqual SyntaxOf('sqrt'), 'texStatement'
  AssertNotEqual SyntaxOf('frac'), 'texStatement'
  let g:vim_markdown_math=1
  syn off | syn on
  AssertEqual SyntaxOf('sqrt'), 'texStatement'
  AssertEqual SyntaxOf('frac'), 'texStatement'

# YAML frontmatter

Given markdown;
---
a: b
---

Execute (YAML frontmatter is controlled by the option):
  AssertNotEqual SyntaxOf('a'), 'yamlBlockMappingKey'
  let g:vim_markdown_frontmatter=1
  syn off | syn on
  AssertEqual SyntaxOf('a'), 'yamlBlockMappingKey'
  let g:vim_markdown_frontmatter=0
  syn off | syn on
  AssertNotEqual SyntaxOf('a'), 'yamlBlockMappingKey'

Given markdown;

---
a: b
---

Execute (YAML frontmatter only works if it's the first thing in the file):
  let g:vim_markdown_frontmatter=1
  syn off | syn on
  AssertNotEqual SyntaxOf('a'), 'yamlBlockMappingKey'

Given markdown;
---
a: b
---

---

Execute (rules are not mistaken by YAML frontmatter delimiters):
  let g:vim_markdown_frontmatter=1
  syn off | syn on
  AssertEqual SyntaxAt(5, 1), 'mkdRule'

# Header

Given markdown;
# #a
ccc

## #b
ddd

Execute (header title starts with #):
  AssertEqual SyntaxOf('a'), 'htmlH1'
  AssertEqual SyntaxOf('b'), 'htmlH2'