Add support for GFM tables

2 files changed, 1794 insertions, 0 deletions

diff --git a/tests/gfm_table.rs b/tests/gfm_table.rs
new file mode 100644
index 0000000..a265549
--- /dev/null
+++ b/tests/gfm_table.rs
@@ -0,0 +1,1782 @@
+extern crate micromark;
+use micromark::{micromark, micromark_with_options, Constructs, Options};
+use pretty_assertions::assert_eq;
+
+#[test]
+fn gfm_table() {
+    let gfm = Options {
+        constructs: Constructs::gfm(),
+        ..Options::default()
+    };
+
+    assert_eq!(
+        micromark("| a |\n| - |\n| b |"),
+        "<p>| a |\n| - |\n| b |</p>",
+        "should ignore tables by default"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n| b |", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>b</td>\n</tr>\n</tbody>\n</table>",
+        "should support tables"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |", &gfm),
+        "<p>| a |</p>",
+        "should not support a table w/ the head row ending in an eof (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a", &gfm),
+        "<p>| a</p>",
+        "should not support a table w/ the head row ending in an eof (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a |", &gfm),
+        "<p>a |</p>",
+        "should not support a table w/ the head row ending in an eof (3)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>",
+        "should support a table w/ a delimiter row ending in an eof (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a\n| -", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>",
+        "should support a table w/ a delimiter row ending in an eof (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n| b |", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>b</td>\n</tr>\n</tbody>\n</table>",
+        "should support a table w/ a body row ending in an eof (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a\n| -\n| b", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>b</td>\n</tr>\n</tbody>\n</table>",
+        "should support a table w/ a body row ending in an eof (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a|b\n-|-\nc|d", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n<th>b</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>c</td>\n<td>d</td>\n</tr>\n</tbody>\n</table>",
+        "should support a table w/ a body row ending in an eof (3)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a  \n| -\t\n| b |     ", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>b</td>\n</tr>\n</tbody>\n</table>",
+        "should support rows w/ trailing whitespace (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a | \n| - |", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>",
+        "should support rows w/ trailing whitespace (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - | ", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>",
+        "should support rows w/ trailing whitespace (3)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n| b | ", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>b</td>\n</tr>\n</tbody>\n</table>",
+        "should support rows w/ trailing whitespace (4)"
+    );
+
+    assert_eq!(
+        micromark_with_options("||a|\n|-|-|", &gfm),
+        "<table>\n<thead>\n<tr>\n<th></th>\n<th>a</th>\n</tr>\n</thead>\n</table>",
+        "should support empty first header cells"
+    );
+
+    assert_eq!(
+        micromark_with_options("|a||\n|-|-|", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n<th></th>\n</tr>\n</thead>\n</table>",
+        "should support empty last header cells"
+    );
+
+    assert_eq!(
+        micromark_with_options("a||b\n-|-|-", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n<th></th>\n<th>b</th>\n</tr>\n</thead>\n</table>",
+        "should support empty header cells"
+    );
+
+    assert_eq!(
+        micromark_with_options("|a|b|\n|-|-|\n||c|", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n<th>b</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td></td>\n<td>c</td>\n</tr>\n</tbody>\n</table>",
+        "should support empty first body cells"
+    );
+
+    assert_eq!(
+        micromark_with_options("|a|b|\n|-|-|\n|c||", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n<th>b</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>c</td>\n<td></td>\n</tr>\n</tbody>\n</table>",
+        "should support empty last body cells"
+    );
+
+    assert_eq!(
+        micromark_with_options("a|b|c\n-|-|-\nd||e", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n<th>b</th>\n<th>c</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>d</td>\n<td></td>\n<td>e</td>\n</tr>\n</tbody>\n</table>",
+        "should support empty body cells"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n- b", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n<ul>\n<li>b</li>\n</ul>",
+        "should support a list after a table"
+    );
+
+    assert_eq!(
+        micromark_with_options("> | a |\n| - |", &gfm),
+        "<blockquote>\n<p>| a |\n| - |</p>\n</blockquote>",
+        "should not support a lazy delimiter row (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("> a\n> | b |\n| - |", &gfm),
+        "<blockquote>\n<p>a\n| b |\n| - |</p>\n</blockquote>",
+        "should not support a lazy delimiter row (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n> | - |", &gfm),
+        "<p>| a |</p>\n<blockquote>\n<p>| - |</p>\n</blockquote>",
+        "should not support a piercing delimiter row"
+    );
+
+    assert_eq!(
+        micromark_with_options("> a\n> | b |\n|-", &gfm),
+        "<blockquote>\n<p>a\n| b |\n|-</p>\n</blockquote>",
+        "should not support a lazy body row (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("> | a |\n> | - |\n| b |", &gfm),
+        "<blockquote>\n<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n</blockquote>\n<p>| b |</p>",
+        "should not support a lazy body row (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("> a\n> | b |\n> | - |\n| c |", &gfm),
+        "<blockquote>\n<p>a</p>\n<table>\n<thead>\n<tr>\n<th>b</th>\n</tr>\n</thead>\n</table>\n</blockquote>\n<p>| c |</p>",
+        "should not support a lazy body row (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("> | A |\n> | - |\n> | 1 |\n| 2 |", &gfm),
+        "<blockquote>\n<table>\n<thead>\n<tr>\n<th>A</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>1</td>\n</tr>\n</tbody>\n</table>\n</blockquote>\n<p>| 2 |</p>",
+        "should not support a lazy body row (3)"
+    );
+
+    assert_eq!(
+        micromark_with_options("   - d\n    - e", &gfm),
+        micromark("   - d\n    - e"),
+        "should not change how lists and lazyness work"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n   | - |", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>",
+        "should form a table if the delimiter row is indented w/ 3 spaces"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n    | - |", &gfm),
+        "<p>| a |\n| - |</p>",
+        "should not form a table if the delimiter row is indented w/ 4 spaces"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n    | - |", &Options {
+            constructs: Constructs {
+                code_indented: false,
+                ..Constructs::gfm()
+            },
+            ..Options::default()
+        }),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>",
+        "should form a table if the delimiter row is indented w/ 4 spaces and indented code is turned off"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n> block quote?", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n<blockquote>\n<p>block quote?</p>\n</blockquote>",
+        "should be interrupted by a block quote"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n>", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n<blockquote>\n</blockquote>",
+        "should be interrupted by a block quote (empty)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n- list?", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n<ul>\n<li>list?</li>\n</ul>",
+        "should be interrupted by a list"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n-", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n<ul>\n<li></li>\n</ul>",
+        "should be interrupted by a list (empty)"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            "| a |\n| - |\n<!-- HTML? -->",
+            &Options {
+                allow_dangerous_html: true,
+                constructs: Constructs::gfm(),
+                ..Options::default()
+            }
+        ),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n<!-- HTML? -->",
+        "should be interrupted by HTML (flow)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n\tcode?", &Options {
+            allow_dangerous_html: true,
+            constructs: Constructs::gfm(),
+            ..Options::default()
+        }),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n<pre><code>code?\n</code></pre>",
+        "should be interrupted by code (indented)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n```js\ncode?", &Options {
+            allow_dangerous_html: true,
+            constructs: Constructs::gfm(),
+            ..Options::default()
+        }),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n<pre><code class=\"language-js\">code?\n</code></pre>\n",
+        "should be interrupted by code (fenced)"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            "| a |\n| - |\n***",
+            &Options {
+                allow_dangerous_html: true,
+                constructs: Constructs::gfm(),
+                ..Options::default()
+            }
+        ),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n<hr />",
+        "should be interrupted by a thematic break"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\n# heading?", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n<h1>heading?</h1>",
+        "should be interrupted by a heading (ATX)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\nheading\n=", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>heading</td>\n</tr>\n<tr>\n<td>=</td>\n</tr>\n</tbody>\n</table>",
+        "should *not* be interrupted by a heading (setext)"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\nheading\n---", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>heading</td>\n</tr>\n</tbody>\n</table>\n<hr />",
+        "should *not* be interrupted by a heading (setext), but interrupt if the underline is also a thematic break"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n| - |\nheading\n-", &gfm),
+        "<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n<tbody>\n<tr>\n<td>heading</td>\n</tr>\n</tbody>\n</table>\n<ul>\n<li></li>\n</ul>",
+        "should *not* be interrupted by a heading (setext), but interrupt if the underline is also an empty list item bullet"
+    );
+
+    assert_eq!(
+        micromark_with_options("a\nb\n-:", &gfm),
+        "<p>a</p>\n<table>\n<thead>\n<tr>\n<th align=\"right\">b</th>\n</tr>\n</thead>\n</table>",
+        "should support a single head row"
+    );
+
+    assert_eq!(
+        micromark_with_options("> | a |\n> | - |", &gfm),
+        "<blockquote>\n<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n</blockquote>",
+        "should support a table in a container"
+    );
+
+    assert_eq!(
+        micromark_with_options("> | a |\n| - |", &gfm),
+        "<blockquote>\n<p>| a |\n| - |</p>\n</blockquote>",
+        "should not support a lazy delimiter row if the head row is in a container"
+    );
+
+    assert_eq!(
+        micromark_with_options("| a |\n> | - |", &gfm),
+        "<p>| a |</p>\n<blockquote>\n<p>| - |</p>\n</blockquote>",
+        "should not support a “piercing” container for the delimiter row, if the head row was not in that container"
+    );
+
+    assert_eq!(
+        micromark_with_options("> | a |\n> | - |\n| c |", &gfm),
+        "<blockquote>\n<table>\n<thead>\n<tr>\n<th>a</th>\n</tr>\n</thead>\n</table>\n</blockquote>\n<p>| c |</p>",
+        "should not support a lazy body row if the head row and delimiter row are in a container"
+    );
+
+    assert_eq!(
+        micromark_with_options("> | a |\n| - |\n> | c |", &gfm),
+        "<blockquote>\n<p>| a |\n| - |\n| c |</p>\n</blockquote>",
+        "should not support a lazy delimiter row if the head row and a further body row are in a container"
+    );
+
+    assert_eq!(micromark_with_options("", &gfm), "", "should support");
+
+    assert_eq!(micromark_with_options("", &gfm), "", "should support");
+
+    assert_eq!(
+        micromark_with_options(
+            r###"# Align
+
+## An empty initial cell
+
+| | a|c|
+|--|:----:|:---|
+|a|b|c|
+|a|b|c|
+
+## Missing alignment characters
+
+| a | b | c |
+|   |---|---|
+| d | e | f |
+
+* * *
+
+| a | b | c |
+|---|---|   |
+| d | e | f |
+
+## Incorrect characters
+
+| a | b | c |
+|---|-*-|---|
+| d | e | f |
+
+## Two alignments
+
+|a|
+|::|
+
+|a|
+|:-:|
+
+## Two at the start or end
+
+|a|
+|::-|
+
+|a|
+|-::|
+
+## In the middle
+
+|a|
+|-:-|
+
+## A space in the middle
+
+|a|
+|- -|
+
+## No pipe
+
+a
+:-:
+
+a
+:-
+
+a
+-:
+
+## A single colon
+
+|a|
+|:|
+
+a
+:
+
+## Alignment on empty cells
+
+| a | b | c | d | e |
+| - | - | :- | -: | :-: |
+| f |
+"###,
+            &gfm
+        ),
+        r###"<h1>Align</h1>
+<h2>An empty initial cell</h2>
+<table>
+<thead>
+<tr>
+<th></th>
+<th align="center">a</th>
+<th align="left">c</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>a</td>
+<td align="center">b</td>
+<td align="left">c</td>
+</tr>
+<tr>
+<td>a</td>
+<td align="center">b</td>
+<td align="left">c</td>
+</tr>
+</tbody>
+</table>
+<h2>Missing alignment characters</h2>
+<p>| a | b | c |
+|   |---|---|
+| d | e | f |</p>
+<hr />
+<p>| a | b | c |
+|---|---|   |
+| d | e | f |</p>
+<h2>Incorrect characters</h2>
+<p>| a | b | c |
+|---|-*-|---|
+| d | e | f |</p>
+<h2>Two alignments</h2>
+<p>|a|
+|::|</p>
+<table>
+<thead>
+<tr>
+<th align="center">a</th>
+</tr>
+</thead>
+</table>
+<h2>Two at the start or end</h2>
+<p>|a|
+|::-|</p>
+<p>|a|
+|-::|</p>
+<h2>In the middle</h2>
+<p>|a|
+|-:-|</p>
+<h2>A space in the middle</h2>
+<p>|a|
+|- -|</p>
+<h2>No pipe</h2>
+<table>
+<thead>
+<tr>
+<th align="center">a</th>
+</tr>
+</thead>
+</table>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+</table>
+<table>
+<thead>
+<tr>
+<th align="right">a</th>
+</tr>
+</thead>
+</table>
+<h2>A single colon</h2>
+<p>|a|
+|:|</p>
+<p>a
+:</p>
+<h2>Alignment on empty cells</h2>
+<table>
+<thead>
+<tr>
+<th>a</th>
+<th>b</th>
+<th align="left">c</th>
+<th align="right">d</th>
+<th align="center">e</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>f</td>
+<td></td>
+<td align="left"></td>
+<td align="right"></td>
+<td align="center"></td>
+</tr>
+</tbody>
+</table>
+"###,
+        "should match alignment like GitHub"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            r###"# Tables
+
+| a | b | c |
+| - | - | - |
+| d | e | f |
+
+## No body
+
+| a | b | c |
+| - | - | - |
+
+## One column
+
+| a |
+| - |
+| b |
+"###,
+            &gfm
+        ),
+        r###"<h1>Tables</h1>
+<table>
+<thead>
+<tr>
+<th>a</th>
+<th>b</th>
+<th>c</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>d</td>
+<td>e</td>
+<td>f</td>
+</tr>
+</tbody>
+</table>
+<h2>No body</h2>
+<table>
+<thead>
+<tr>
+<th>a</th>
+<th>b</th>
+<th>c</th>
+</tr>
+</thead>
+</table>
+<h2>One column</h2>
+<table>
+<thead>
+<tr>
+<th>a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>b</td>
+</tr>
+</tbody>
+</table>
+"###,
+        "should match basic like GitHub"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            r###"# Tables in things
+
+## In lists
+
+*   Unordered:
+
+    | A | B |
+    | - | - |
+    | 1 | 2 |
+
+1.  Ordered:
+
+    | A | B |
+    | - | - |
+    | 1 | 2 |
+
+*   Lazy?
+    | A | B |
+    | - | - |
+   | 1 | 2 |
+  | 3 | 4 |
+ | 5 | 6 |
+| 7 | 8 |
+
+## In block quotes
+
+> W/ space:
+> | A | B |
+> | - | - |
+> | 1 | 2 |
+
+>W/o space:
+>| A | B |
+>| - | - |
+>| 1 | 2 |
+
+> Lazy?
+> | A | B |
+> | - | - |
+> | 1 | 2 |
+>| 3 | 4 |
+| 5 | 6 |
+
+### List interrupting delimiters
+
+a |
+- |
+
+a
+-|
+
+a
+|-
+"###,
+            &gfm
+        ),
+        r###"<h1>Tables in things</h1>
+<h2>In lists</h2>
+<ul>
+<li>
+<p>Unordered:</p>
+<table>
+<thead>
+<tr>
+<th>A</th>
+<th>B</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>1</td>
+<td>2</td>
+</tr>
+</tbody>
+</table>
+</li>
+</ul>
+<ol>
+<li>
+<p>Ordered:</p>
+<table>
+<thead>
+<tr>
+<th>A</th>
+<th>B</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>1</td>
+<td>2</td>
+</tr>
+</tbody>
+</table>
+</li>
+</ol>
+<ul>
+<li>Lazy?
+<table>
+<thead>
+<tr>
+<th>A</th>
+<th>B</th>
+</tr>
+</thead>
+</table>
+</li>
+</ul>
+<p>| 1 | 2 |
+| 3 | 4 |
+| 5 | 6 |
+| 7 | 8 |</p>
+<h2>In block quotes</h2>
+<blockquote>
+<p>W/ space:</p>
+<table>
+<thead>
+<tr>
+<th>A</th>
+<th>B</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>1</td>
+<td>2</td>
+</tr>
+</tbody>
+</table>
+</blockquote>
+<blockquote>
+<p>W/o space:</p>
+<table>
+<thead>
+<tr>
+<th>A</th>
+<th>B</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>1</td>
+<td>2</td>
+</tr>
+</tbody>
+</table>
+</blockquote>
+<blockquote>
+<p>Lazy?</p>
+<table>
+<thead>
+<tr>
+<th>A</th>
+<th>B</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>1</td>
+<td>2</td>
+</tr>
+<tr>
+<td>3</td>
+<td>4</td>
+</tr>
+</tbody>
+</table>
+</blockquote>
+<p>| 5 | 6 |</p>
+<h3>List interrupting delimiters</h3>
+<p>a |</p>
+<ul>
+<li>|</li>
+</ul>
+<table>
+<thead>
+<tr>
+<th>a</th>
+</tr>
+</thead>
+</table>
+<table>
+<thead>
+<tr>
+<th>a</th>
+</tr>
+</thead>
+</table>
+"###,
+        "should match containers like GitHub"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            r###"| a |
+| - |
+| - |
+| 1 |
+"###,
+            &gfm
+        ),
+        r###"<table>
+<thead>
+<tr>
+<th>a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>-</td>
+</tr>
+<tr>
+<td>1</td>
+</tr>
+</tbody>
+</table>
+"###,
+        "should match a double delimiter row like GitHub"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            r###"# Examples from GFM
+
+## A
+
+| foo | bar |
+| --- | --- |
+| baz | bim |
+
+## B
+
+| abc | defghi |
+:-: | -----------:
+bar | baz
+
+## C
+
+| f\|oo  |
+| ------ |
+| b `\|` az |
+| b **\|** im |
+
+## D
+
+| abc | def |
+| --- | --- |
+| bar | baz |
+> bar
+
+## E
+
+| abc | def |
+| --- | --- |
+| bar | baz |
+bar
+
+bar
+
+## F
+
+| abc | def |
+| --- |
+| bar |
+
+## G
+
+| abc | def |
+| --- | --- |
+| bar |
+| bar | baz | boo |
+
+## H
+
+| abc | def |
+| --- | --- |
+"###,
+            &gfm
+        ),
+        r###"<h1>Examples from GFM</h1>
+<h2>A</h2>
+<table>
+<thead>
+<tr>
+<th>foo</th>
+<th>bar</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>baz</td>
+<td>bim</td>
+</tr>
+</tbody>
+</table>
+<h2>B</h2>
+<table>
+<thead>
+<tr>
+<th align="center">abc</th>
+<th align="right">defghi</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="center">bar</td>
+<td align="right">baz</td>
+</tr>
+</tbody>
+</table>
+<h2>C</h2>
+<table>
+<thead>
+<tr>
+<th>f|oo</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>b <code>|</code> az</td>
+</tr>
+<tr>
+<td>b <strong>|</strong> im</td>
+</tr>
+</tbody>
+</table>
+<h2>D</h2>
+<table>
+<thead>
+<tr>
+<th>abc</th>
+<th>def</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>bar</td>
+<td>baz</td>
+</tr>
+</tbody>
+</table>
+<blockquote>
+<p>bar</p>
+</blockquote>
+<h2>E</h2>
+<table>
+<thead>
+<tr>
+<th>abc</th>
+<th>def</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>bar</td>
+<td>baz</td>
+</tr>
+<tr>
+<td>bar</td>
+<td></td>
+</tr>
+</tbody>
+</table>
+<p>bar</p>
+<h2>F</h2>
+<p>| abc | def |
+| --- |
+| bar |</p>
+<h2>G</h2>
+<table>
+<thead>
+<tr>
+<th>abc</th>
+<th>def</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>bar</td>
+<td></td>
+</tr>
+<tr>
+<td>bar</td>
+<td>baz</td>
+</tr>
+</tbody>
+</table>
+<h2>H</h2>
+<table>
+<thead>
+<tr>
+<th>abc</th>
+<th>def</th>
+</tr>
+</thead>
+</table>
+"###,
+        "should match examples from the GFM spec like GitHub"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            r###"# Grave accents
+
+## Grave accent in cell
+
+| A            | B |
+|--------------|---|
+| <kbd>`</kbd> | C |
+
+## Escaped grave accent in “inline code” in cell
+
+| A   |
+|-----|
+| `\` |
+
+## “Empty” inline code
+
+| 1 | 2    | 3  |
+|---|------|----|
+| a |   `` |    |
+| b |   `` | `` |
+| c |    ` | `  |
+| d |     `|`   |
+| e | `\|` |    |
+| f |   \| |    |
+
+## Escaped pipes in code in cells
+
+| `\|\\` |
+| --- |
+| `\|\\` |
+
+`\|\\`
+"###,
+            &Options {
+                allow_dangerous_html: true,
+                ..gfm.clone()
+            }
+        ),
+        r###"<h1>Grave accents</h1>
+<h2>Grave accent in cell</h2>
+<table>
+<thead>
+<tr>
+<th>A</th>
+<th>B</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td><kbd>`</kbd></td>
+<td>C</td>
+</tr>
+</tbody>
+</table>
+<h2>Escaped grave accent in “inline code” in cell</h2>
+<table>
+<thead>
+<tr>
+<th>A</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td><code>\</code></td>
+</tr>
+</tbody>
+</table>
+<h2>“Empty” inline code</h2>
+<table>
+<thead>
+<tr>
+<th>1</th>
+<th>2</th>
+<th>3</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>a</td>
+<td>``</td>
+<td></td>
+</tr>
+<tr>
+<td>b</td>
+<td>``</td>
+<td>``</td>
+</tr>
+<tr>
+<td>c</td>
+<td>`</td>
+<td>`</td>
+</tr>
+<tr>
+<td>d</td>
+<td>`</td>
+<td>`</td>
+</tr>
+<tr>
+<td>e</td>
+<td><code>|</code></td>
+<td></td>
+</tr>
+<tr>
+<td>f</td>
+<td>|</td>
+<td></td>
+</tr>
+</tbody>
+</table>
+<h2>Escaped pipes in code in cells</h2>
+<table>
+<thead>
+<tr>
+<th><code>|\\</code></th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td><code>|\\</code></td>
+</tr>
+</tbody>
+</table>
+<p><code>\|\\</code></p>
+"###,
+        "should match grave accent like GitHub"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            r###"# Code
+
+## Indented delimiter row
+
+a
+   |-
+
+a
+    |-
+
+## Indented body
+
+| a |
+ | - |
+  | C |
+   | D |
+    | E |
+"###,
+            &gfm
+        ),
+        r###"<h1>Code</h1>
+<h2>Indented delimiter row</h2>
+<table>
+<thead>
+<tr>
+<th>a</th>
+</tr>
+</thead>
+</table>
+<p>a
+|-</p>
+<h2>Indented body</h2>
+<table>
+<thead>
+<tr>
+<th>a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>C</td>
+</tr>
+<tr>
+<td>D</td>
+</tr>
+</tbody>
+</table>
+<pre><code>| E |
+</code></pre>
+"###,
+        "should match indent like GitHub"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            r###"## Blank line
+
+a
+:-
+b
+
+c
+
+## Block quote
+
+a
+:-
+b
+> c
+
+## Code (fenced)
+
+a
+:-
+b
+```
+c
+```
+
+## Code (indented)
+
+a
+:-
+b
+    c
+
+## Definition
+
+a
+:-
+b
+[c]: d
+
+## Heading (atx)
+
+a
+:-
+b
+# c
+
+
+## Heading (setext) (rank 1)
+
+a
+:-
+b
+==
+c
+
+## Heading (setext) (rank 2)
+
+a
+:-
+b
+--
+c
+
+## HTML (flow, kind 1: raw)
+
+a
+:-
+b
+<pre>
+  a
+</pre>
+
+## HTML (flow, kind 2: comment)
+
+a
+:-
+b
+<!-- c -->
+
+## HTML (flow, kind 3: instruction)
+
+a
+:-
+b
+<? c ?>
+
+## HTML (flow, kind 4: declaration)
+
+a
+:-
+b
+<!C>
+
+## HTML (flow, kind 5: cdata)
+
+a
+:-
+b
+<![CDATA[c]]>
+
+## HTML (flow, kind 6: basic)
+
+a
+:-
+b
+<div>
+
+## HTML (flow, kind 7: complete)
+
+a
+:-
+b
+<x>
+
+## List (ordered, 1)
+
+a
+:-
+b
+1. c
+
+## List (ordered, other)
+
+a
+:-
+b
+2. c
+
+## List (unordered)
+
+a
+:-
+b
+* c
+
+## List (unordered, blank)
+
+a
+:-
+b
+*
+c
+
+## List (unordered, blank start)
+
+a
+:-
+b
+*
+  c
+
+## Thematic break
+
+a
+:-
+b
+***
+"###,
+            &Options {
+                allow_dangerous_html: true,
+                ..gfm.clone()
+            }
+        ),
+        r###"<h2>Blank line</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<p>c</p>
+<h2>Block quote</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<blockquote>
+<p>c</p>
+</blockquote>
+<h2>Code (fenced)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<pre><code>c
+</code></pre>
+<h2>Code (indented)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<pre><code>c
+</code></pre>
+<h2>Definition</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+<tr>
+<td align="left">[c]: d</td>
+</tr>
+</tbody>
+</table>
+<h2>Heading (atx)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<h1>c</h1>
+<h2>Heading (setext) (rank 1)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+<tr>
+<td align="left">==</td>
+</tr>
+<tr>
+<td align="left">c</td>
+</tr>
+</tbody>
+</table>
+<h2>Heading (setext) (rank 2)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+<tr>
+<td align="left">--</td>
+</tr>
+<tr>
+<td align="left">c</td>
+</tr>
+</tbody>
+</table>
+<h2>HTML (flow, kind 1: raw)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<pre>
+  a
+</pre>
+<h2>HTML (flow, kind 2: comment)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<!-- c -->
+<h2>HTML (flow, kind 3: instruction)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<? c ?>
+<h2>HTML (flow, kind 4: declaration)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<!C>
+<h2>HTML (flow, kind 5: cdata)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<![CDATA[c]]>
+<h2>HTML (flow, kind 6: basic)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<div>
+<h2>HTML (flow, kind 7: complete)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<x>
+<h2>List (ordered, 1)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<ol>
+<li>c</li>
+</ol>
+<h2>List (ordered, other)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<ol start="2">
+<li>c</li>
+</ol>
+<h2>List (unordered)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<ul>
+<li>c</li>
+</ul>
+<h2>List (unordered, blank)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<ul>
+<li></li>
+</ul>
+<p>c</p>
+<h2>List (unordered, blank start)</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<ul>
+<li>c</li>
+</ul>
+<h2>Thematic break</h2>
+<table>
+<thead>
+<tr>
+<th align="left">a</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td align="left">b</td>
+</tr>
+</tbody>
+</table>
+<hr />
+"###,
+        "should match interrupt like GitHub"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            r###"# Loose
+
+## Loose
+
+Header 1 | Header 2
+-------- | --------
+Cell 1   | Cell 2
+Cell 3   | Cell 4
+
+## One “column”, loose
+
+a
+-
+b
+
+## No pipe in first row
+
+a
+| - |
+"###,
+            &gfm
+        ),
+        r###"<h1>Loose</h1>
+<h2>Loose</h2>
+<table>
+<thead>
+<tr>
+<th>Header 1</th>
+<th>Header 2</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>Cell 1</td>
+<td>Cell 2</td>
+</tr>
+<tr>
+<td>Cell 3</td>
+<td>Cell 4</td>
+</tr>
+</tbody>
+</table>
+<h2>One “column”, loose</h2>
+<h2>a</h2>
+<p>b</p>
+<h2>No pipe in first row</h2>
+<table>
+<thead>
+<tr>
+<th>a</th>
+</tr>
+</thead>
+</table>
+"###,
+        "should match loose tables like GitHub"
+    );
+
+    assert_eq!(
+        micromark_with_options(
+            r###"# Some more escapes
+
+| Head          |
+| ------------- |
+| A | Alpha     |
+| B \| Bravo    |
+| C \\| Charlie |
+| D \\\| Delta  |
+| E \\\\| Echo  |
+
+Note: GH has a bug where in case C and E, the escaped escape is treated as a
+normal escape: <https://github.com/github/cmark-gfm/issues/277>.
+"###,
+            &gfm
+        ),
+        r###"<h1>Some more escapes</h1>
+<table>
+<thead>
+<tr>
+<th>Head</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>A</td>
+</tr>
+<tr>
+<td>B | Bravo</td>
+</tr>
+<tr>
+<td>C \</td>
+</tr>
+<tr>
+<td>D \| Delta</td>
+</tr>
+<tr>
+<td>E \\</td>
+</tr>
+</tbody>
+</table>
+<p>Note: GH has a bug where in case C and E, the escaped escape is treated as a
+normal escape: <a href="https://github.com/github/cmark-gfm/issues/277">https://github.com/github/cmark-gfm/issues/277</a>.</p>
+"###,
+        "should match loose escapes like GitHub"
+    );
+}
diff --git a/tests/heading_setext.rs b/tests/heading_setext.rs
index 22155f0..fa979be 100644
--- a/tests/heading_setext.rs
+++ b/tests/heading_setext.rs
@@ -258,6 +258,18 @@ fn heading_setext() {
     );
 
     assert_eq!(
+        micromark("a\n- ==="),
+        "<p>a</p>\n<ul>\n<li>===</li>\n</ul>",
+        "should not support piercing (1)"
+    );
+
+    assert_eq!(
+        micromark("a\n* ---"),
+        "<p>a</p>\n<ul>\n<li>\n<hr />\n</li>\n</ul>",
+        "should not support piercing (2)"
+    );
+
+    assert_eq!(
         micromark_with_options(
             "a\n-",
             &Options {