# Coverage

This file is just a collection of unit tests not covered elsewhere.

Most notably regression tests, tests improving code coverage and other useful
things may drop here.

(However any tests requiring any additional command line option, like enabling
an extension, must be included in their respective files.)


## GitHub Issues

### [Issue 2](https://github.com/mity/md4c/issues/2)

Raw HTML block:

```````````````````````````````` example
<gi att1=tok1 att2=tok2>
.
<gi att1=tok1 att2=tok2>
````````````````````````````````

Inline:

```````````````````````````````` example
foo <gi att1=tok1 att2=tok2> bar
.
<p>foo <gi att1=tok1 att2=tok2> bar</p>
````````````````````````````````

Inline with a line break:

```````````````````````````````` example
foo <gi att1=tok1
att2=tok2> bar
.
<p>foo <gi att1=tok1
att2=tok2> bar</p>
````````````````````````````````


### [Issue 4](https://github.com/mity/md4c/issues/4)

```````````````````````````````` example
![alt text with *entity* &copy;](img.png 'title')
.
<p><img src="img.png" alt="alt text with entity ©" title="title"></p>
````````````````````````````````


### [Issue 9](https://github.com/mity/md4c/issues/9)

```````````````````````````````` example
> [foo
> bar]: /url
>
> [foo bar]
.
<blockquote>
<p><a href="/url">foo
bar</a></p>
</blockquote>
````````````````````````````````


### [Issue 10](https://github.com/mity/md4c/issues/10)

```````````````````````````````` example
[x]:
x
- <?

  x
.
<ul>
<li><?

x
</li>
</ul>
````````````````````````````````


### [Issue 11](https://github.com/mity/md4c/issues/11)

```````````````````````````````` example
x [link](/url "foo &ndash; bar") x
.
<p>x <a href="/url" title="foo – bar">link</a> x</p>
````````````````````````````````


### [Issue 14](https://github.com/mity/md4c/issues/14)

```````````````````````````````` example
a***b* c*
.
<p>a*<em><em>b</em> c</em></p>
````````````````````````````````


### [Issue 15](https://github.com/mity/md4c/issues/15)

```````````````````````````````` example
***b* c*
.
<p>*<em><em>b</em> c</em></p>
````````````````````````````````


### [Issue 21](https://github.com/mity/md4c/issues/21)

```````````````````````````````` example
a*b**c*
.
<p>a<em>b**c</em></p>
````````````````````````````````


### [Issue 33](https://github.com/mity/md4c/issues/33)

```````````````````````````````` example
```&amp;&amp;&amp;&amp;&amp;&amp;&amp;&amp;
.
<pre><code class="language-&amp;&amp;&amp;&amp;&amp;&amp;&amp;&amp;"></code></pre>
````````````````````````````````


### [Issue 36](https://github.com/mity/md4c/issues/36)

```````````````````````````````` example
__x_ _x___
.
<p><em><em>x</em> <em>x</em></em>_</p>
````````````````````````````````


### [Issue 39](https://github.com/mity/md4c/issues/39)

```````````````````````````````` example
[\\]: x
.
````````````````````````````````


### [Issue 40](https://github.com/mity/md4c/issues/40)

```````````````````````````````` example
[x](url
'title'
)x
.
<p><a href="url" title="title">x</a>x</p>
````````````````````````````````


### [Issue 65](https://github.com/mity/md4c/issues/65)

```````````````````````````````` example
`
.
<p>`</p>
````````````````````````````````


### [Issue 74](https://github.com/mity/md4c/issues/74)

```````````````````````````````` example
[f]:
-
    xx
-
.
<pre><code>xx
</code></pre>
<ul>
<li></li>
</ul>
````````````````````````````````


### [Issue 78](https://github.com/mity/md4c/issues/78)

```````````````````````````````` example
[SS ẞ]: /url
[ẞ SS]
.
<p><a href="/url">ẞ SS</a></p>
````````````````````````````````


### [Issue 83](https://github.com/mity/md4c/issues/83)

```````````````````````````````` example
foo
>
.
<p>foo</p>
<blockquote>
</blockquote>

````````````````````````````````


### [Issue 95](https://github.com/mity/md4c/issues/95)

```````````````````````````````` example
. foo
.
<p>. foo</p>
````````````````````````````````


### [Issue 96](https://github.com/mity/md4c/issues/96)

```````````````````````````````` example
[ab]: /foo
[a] [ab] [abc]
.
<p>[a] <a href="/foo">ab</a> [abc]</p>
````````````````````````````````

```````````````````````````````` example
[a b]: /foo
[a   b]
.
<p><a href="/foo">a   b</a></p>
````````````````````````````````


### [Issue 97](https://github.com/mity/md4c/issues/97)

```````````````````````````````` example
*a **b c* d**
.
<p><em>a <em><em>b c</em> d</em></em></p>

````````````````````````````````


### [Issue 100](https://github.com/mity/md4c/issues/100)

```````````````````````````````` example
<foo@123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123>
.
<p><a href="mailto:foo@123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123">foo@123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123</a></p>
````````````````````````````````

```````````````````````````````` example
<foo@123456789012345678901234567890123456789012345678901234567890123x.123456789012345678901234567890123456789012345678901234567890123>
.
<p>&lt;foo@123456789012345678901234567890123456789012345678901234567890123x.123456789012345678901234567890123456789012345678901234567890123&gt;</p>
````````````````````````````````
(Note the `x` here which turns it over the max. allowed length limit.)


### [Issue 107](https://github.com/mity/md4c/issues/107)

```````````````````````````````` example
***foo *bar baz***
.
<p>*<strong>foo <em>bar baz</em></strong></p>

````````````````````````````````


### [Issue 124](https://github.com/mity/md4c/issues/124)

```````````````````````````````` example
~~~
                x
~~~

~~~
                 x
~~~
.
<pre><code>                x
</code></pre>
<pre><code>                 x
</code></pre>
````````````````````````````````


### [Issue 131](https://github.com/mity/md4c/issues/131)

```````````````````````````````` example
[![alt][img]][link]

[img]: img_url
[link]: link_url
.
<p><a href="link_url"><img src="img_url" alt="alt"></a></p>
````````````````````````````````


### [Issue 142](https://github.com/mity/md4c/issues/142)

```````````````````````````````` example
[fooﬗ]: /url
[fooﬕ]
.
<p>[fooﬕ]</p>
````````````````````````````````


### [Issue 149](https://github.com/mity/md4c/issues/149)

```````````````````````````````` example
- <script>
- foo
bar
</script>
.
<ul>
<li><script>
</li>
<li>foo
bar
</script></li>
</ul>
````````````````````````````````


## Code coverage

### `md_is_unicode_whitespace__()`

Unicode whitespace (here U+2000) forms a word boundary so these cannot be
resolved as emphasis span because there is no closer mark.

```````````````````````````````` example
*foo *bar
.
<p>*foo *bar</p>
````````````````````````````````


### `md_is_unicode_punct__()`

Ditto for Unicode punctuation (here U+00A1).

```````````````````````````````` example
*foo¡*bar
.
<p>*foo¡*bar</p>
````````````````````````````````


### `md_get_unicode_fold_info()`

```````````````````````````````` example
[Příliš žluťoučký kůň úpěl ďábelské ódy.]

[PŘÍLIŠ ŽLUŤOUČKÝ KŮŇ ÚPĚL ĎÁBELSKÉ ÓDY.]: /url
.
<p><a href="/url">Příliš žluťoučký kůň úpěl ďábelské ódy.</a></p>
````````````````````````````````


### `md_decode_utf8__()` and `md_decode_utf8_before__()`

```````````````````````````````` example
á*Á (U+00E1, i.e. two byte UTF-8 sequence)
 *  (U+2000, i.e. three byte UTF-8 sequence)
.
<p>á*Á (U+00E1, i.e. two byte UTF-8 sequence)
 *  (U+2000, i.e. three byte UTF-8 sequence)</p>
````````````````````````````````


### `md_is_link_destination_A()`

```````````````````````````````` example
[link](</url\.with\.escape>)
.
<p><a href="/url.with.escape">link</a></p>
````````````````````````````````


### `md_link_label_eq()`

```````````````````````````````` example
[foo bar]

[foo bar]: /url
.
<p><a href="/url">foo bar</a></p>
````````````````````````````````


### `md_is_inline_link_spec()`

```````````````````````````````` example
> [link](/url 'foo
> bar')
.
<blockquote>
<p><a href="/url" title="foo
bar">link</a></p>
</blockquote>
````````````````````````````````


### `md_build_ref_def_hashtable()`

All link labels in the following example all have the same FNV1a hash (after
normalization of the label, which means after converting to a vector of Unicode
codepoints and lowercase folding).

So the example triggers quite complex code paths which are not otherwise easily
tested.

```````````````````````````````` example
[foo]: /foo
[qnptgbh]: /qnptgbh
[abgbrwcv]: /abgbrwcv
[abgbrwcv]: /abgbrwcv2
[abgbrwcv]: /abgbrwcv3
[abgbrwcv]: /abgbrwcv4
[alqadfgn]: /alqadfgn

[foo]
[qnptgbh]
[abgbrwcv]
[alqadfgn]
[axgydtdu]
.
<p><a href="/foo">foo</a>
<a href="/qnptgbh">qnptgbh</a>
<a href="/abgbrwcv">abgbrwcv</a>
<a href="/alqadfgn">alqadfgn</a>
[axgydtdu]</p>
````````````````````````````````

For the sake of completeness, the following C program was used to find the hash
collisions by brute force:

~~~

#include <stdio.h>
#include <string.h>


static unsigned etalon;



#define MD_FNV1A_BASE       2166136261
#define MD_FNV1A_PRIME      16777619

static inline unsigned
fnv1a(unsigned base, const void* data, size_t n)
{
    const unsigned char* buf = (const unsigned char*) data;
    unsigned hash = base;
    size_t i;

    for(i = 0; i < n; i++) {
        hash ^= buf[i];
        hash *= MD_FNV1A_PRIME;
    }

    return hash;
}


static unsigned
unicode_hash(const char* data, size_t n)
{
    unsigned value;
    unsigned hash = MD_FNV1A_BASE;
    int i;

    for(i = 0; i < n; i++) {
        value = data[i];
        hash = fnv1a(hash, &value, sizeof(unsigned));
    }

    return hash;
}


static void
recurse(char* buffer, size_t off, size_t len)
{
    int ch;

    if(off < len - 1) {
        for(ch = 'a'; ch <= 'z'; ch++) {
            buffer[off] = ch;
            recurse(buffer, off+1, len);
        }
    } else {
        for(ch = 'a'; ch <= 'z'; ch++) {
            buffer[off] = ch;
            if(unicode_hash(buffer, len) == etalon) {
                printf("Dup: %.*s\n", (int)len, buffer);
            }
        }
    }
}

int
main(int argc, char** argv)
{
    char buffer[32];
    int len;

    if(argc < 2)
        etalon = unicode_hash("foo", 3);
    else
        etalon = unicode_hash(argv[1], strlen(argv[1]));

    for(len = 1; len <= sizeof(buffer); len++)
        recurse(buffer, 0, len);

    return 0;
}
~~~