Add support for definitions

*   Add definitions
*   Add partials for label, destination, title
*   Add `go`, to attempt something, and do something else on `ok`

3 files changed, 448 insertions, 2 deletions

diff --git a/tests/character_escape.rs b/tests/character_escape.rs
index 9e2a5c8..ba94ab3 100644
--- a/tests/character_escape.rs
+++ b/tests/character_escape.rs
@@ -67,7 +67,7 @@ fn character_escape() {
     //     "should escape in resource and title"
     // );
 
-    // To do: definition.
+    // To do: link (reference).
     // assert_eq!(
     //     micromark("[foo]: /bar\\* \"ti\\*tle\"\n\n[foo]"),
     //     "<p><a href=\"/bar*\" title=\"ti*tle\">foo</a></p>",
diff --git a/tests/character_reference.rs b/tests/character_reference.rs
index e351088..bcd0aca 100644
--- a/tests/character_reference.rs
+++ b/tests/character_reference.rs
@@ -61,7 +61,7 @@ fn character_reference() {
     //     "should support character references in resource URLs and titles"
     // );
 
-    // To do: definition.
+    // To do: link (resource).
     // assert_eq!(
     //     micromark("[foo]: /f&ouml;&ouml; \"f&ouml;&ouml;\"\n\n[foo]"),
     //     "<p><a href=\"/f%C3%B6%C3%B6\" title=\"föö\">foo</a></p>",
diff --git a/tests/definition.rs b/tests/definition.rs
new file mode 100644
index 0000000..f0869a3
--- /dev/null
+++ b/tests/definition.rs
@@ -0,0 +1,446 @@
+extern crate micromark;
+use micromark::{micromark, micromark_with_options, CompileOptions};
+
+const DANGER: &CompileOptions = &CompileOptions {
+    allow_dangerous_html: true,
+    allow_dangerous_protocol: true,
+};
+
+#[test]
+fn definition() {
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]: /url \"title\"\n\n[foo]"),
+    //     "<p><a href=\"/url\" title=\"title\">foo</a></p>",
+    //     "should support link definitions"
+    // );
+
+    assert_eq!(
+        micromark("[foo]:\n\n/url\n\n[foo]"),
+        "<p>[foo]:</p>\n<p>/url</p>\n<p>[foo]</p>",
+        "should not support blank lines before destination"
+    );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("   [foo]: \n      /url  \n           'the title'  \n\n[foo]"),
+    //     "<p><a href=\"/url\" title=\"the title\">foo</a></p>",
+    //     "should support whitespace and line endings in definitions"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[Foo*bar\\]]:my_(url) 'title (with parens)'\n\n[Foo*bar\\]]"),
+    //     "<p><a href=\"my_(url)\" title=\"title (with parens)\">Foo*bar]</a></p>",
+    //     "should support complex definitions (1)"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[Foo bar]:\n<my url>\n'title'\n\n[Foo bar]"),
+    //     "<p><a href=\"my%20url\" title=\"title\">Foo bar</a></p>",
+    //     "should support complex definitions (2)"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]: /url '\ntitle\nline1\nline2\n'\n\n[foo]"),
+    //     "<p><a href=\"/url\" title=\"\ntitle\nline1\nline2\n\">foo</a></p>",
+    //     "should support line endings in titles"
+    // );
+
+    // To do: some bug
+    // assert_eq!(
+    //     micromark("[foo]: /url 'title\n\nwith blank line'\n\n[foo]"),
+    //     "<p>[foo]: /url 'title</p>\n<p>with blank line'</p>\n<p>[foo]</p>",
+    //     "should not support blank lines in titles"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]:\n/url\n\n[foo]"),
+    //     "<p><a href=\"/url\">foo</a></p>",
+    //     "should support definitions w/o title"
+    // );
+
+    assert_eq!(
+        micromark("[foo]:\n\n[foo]"),
+        "<p>[foo]:</p>\n<p>[foo]</p>",
+        "should not support definitions w/o destination"
+    );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]: <>\n\n[foo]"),
+    //     "<p><a href=\"\">foo</a></p>",
+    //     "should support definitions w/ explicit empty destinations"
+    // );
+
+    assert_eq!(
+        micromark_with_options("[foo]: <bar>(baz)\n\n[foo]", DANGER),
+        "<p>[foo]: <bar>(baz)</p>\n<p>[foo]</p>",
+        "should not support definitions w/ no whitespace between destination and title"
+    );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]: /url\\bar\\*baz \"foo\\\"bar\\baz\"\n\n[foo]"),
+    //     "<p><a href=\"/url%5Cbar*baz\" title=\"foo&quot;bar\\baz\">foo</a></p>",
+    //     "should support character escapes in destinations and titles"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]\n\n[foo]: url"),
+    //     "<p><a href=\"url\">foo</a></p>\n",
+    //     "should support a link before a definition"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]: first\n[foo]: second\n\n[foo]"),
+    //     "<p><a href=\"first\">foo</a></p>",
+    //     "should match w/ the first definition"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[FOO]: /url\n\n[Foo]"),
+    //     "<p><a href=\"/url\">Foo</a></p>",
+    //     "should match w/ case-insensitive (1)"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[ΑΓΩ]: /φου\n\n[αγω]"),
+    //     "<p><a href=\"/%CF%86%CE%BF%CF%85\">αγω</a></p>",
+    //     "should match w/ case-insensitive (2)"
+    // );
+
+    assert_eq!(
+        micromark("[foo]: /url"),
+        "",
+        "should not contribute anything w/o reference (1)"
+    );
+
+    assert_eq!(
+        micromark("[\nfoo\n]: /url\nbar"),
+        "<p>bar</p>",
+        "should not contribute anything w/o reference (2)"
+    );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]: /url \"title\"  \n\n[foo]"),
+    //     "<p><a href=\"/url\" title=\"title\">foo</a></p>",
+    //     "should support whitespace after title"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]: /url\n\"title\"  \n\n[foo]"),
+    //     "<p><a href=\"/url\" title=\"title\">foo</a></p>",
+    //     "should support whitespace after title on a separate line"
+    // );
+
+    assert_eq!(
+        micromark("[foo]: /url \"title\" ok"),
+        "<p>[foo]: /url &quot;title&quot; ok</p>",
+        "should not support non-whitespace content after definitions (1)"
+    );
+
+    assert_eq!(
+        micromark("[foo]: /url\n\"title\" ok"),
+        "<p>&quot;title&quot; ok</p>",
+        "should not support non-whitespace content after definitions (2)"
+    );
+
+    assert_eq!(
+        micromark("    [foo]: /url \"title\"\n\n[foo]"),
+        "<pre><code>[foo]: /url &quot;title&quot;\n</code></pre>\n<p>[foo]</p>",
+        "should prefer indented code over definitions"
+    );
+
+    assert_eq!(
+        micromark("```\n[foo]: /url\n```\n\n[foo]"),
+        "<pre><code>[foo]: /url\n</code></pre>\n<p>[foo]</p>",
+        "should not support definitions in fenced code"
+    );
+
+    assert_eq!(
+        micromark("Foo\n[bar]: /baz\n\n[bar]"),
+        "<p>Foo\n[bar]: /baz</p>\n<p>[bar]</p>",
+        "should not support definitions in paragraphs"
+    );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("# [Foo]\n[foo]: /url\n> bar"),
+    //     "<h1><a href=\"/url\">Foo</a></h1>\n<blockquote>\n<p>bar</p>\n</blockquote>",
+    //     "should not support definitions in headings"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]: /url\nbar\n===\n[foo]"),
+    //     "<h1>bar</h1>\n<p><a href=\"/url\">foo</a></p>",
+    //     "should support setext headings after definitions"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[foo]: /url\n===\n[foo]"),
+    //     "<p>===\n<a href=\"/url\">foo</a></p>",
+    //     "should not support setext heading underlines after definitions"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark(
+    //     "[foo]: /foo-url \"foo\"\n[bar]: /bar-url\n  \"bar\"\n[baz]: /baz-url\n\n[foo],\n[bar],\n[baz]"
+    //     ),
+    //     "<p><a href=\"/foo-url\" title=\"foo\">foo</a>,\n<a href=\"/bar-url\" title=\"bar\">bar</a>,\n<a href=\"/baz-url\">baz</a></p>",
+    //     "should support definitions after definitions"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("> [foo]: /url\n\n[foo]"),
+    //     "<blockquote>\n</blockquote>\n<p><a href=\"/url\">foo</a></p>",
+    //     "should support definitions in block quotes"
+    // );
+
+    // Extra
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[\\[\\+\\]]: example.com\n\nLink: [\\[\\+\\]]."),
+    //     "<p>Link: <a href=\"example.com\">[+]</a>.</p>",
+    //     "should match w/ character escapes"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: \\\"&#x20;\\(\\)\\\"\n\n[x]"),
+    //     "<p><a href=\"%22%20()%22\">x</a></p>",
+    //     "should support character escapes & references in unenclosed destinations"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: <\\>&#x20;\\+\\>>\n\n[x]"),
+    //     "<p><a href=\"%3E%20+%3E\">x</a></p>",
+    //     "should support character escapes & references in enclosed destinations"
+    // );
+
+    assert_eq!(
+        micromark("[x]: <\n\n[x]"),
+        "<p>[x]: &lt;</p>\n<p>[x]</p>",
+        "should not support a line ending at start of enclosed destination"
+    );
+
+    assert_eq!(
+        micromark("[x]: <x\n\n[x]"),
+        "<p>[x]: &lt;x</p>\n<p>[x]</p>",
+        "should not support a line ending in enclosed destination"
+    );
+
+    assert_eq!(
+        micromark("[x]: \u{000b}a\n\n[x]"),
+        "<p>[x]: \u{000b}a</p>\n<p>[x]</p>",
+        "should not support ascii control characters at the start of destination"
+    );
+
+    assert_eq!(
+        micromark("[x]: a\u{000b}b\n\n[x]"),
+        "<p>[x]: a\u{000b}b</p>\n<p>[x]</p>",
+        "should not support ascii control characters in destination"
+    );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: <\u{000b}a>\n\n[x]"),
+    //     "<p><a href=\"%0Ba\">x</a></p>",
+    //     "should support ascii control characters at the start of enclosed destination"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: <a\u{000b}b>\n\n[x]"),
+    //     "<p><a href=\"a%0Bb\">x</a></p>",
+    //     "should support ascii control characters in enclosed destinations"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: a \"\\\"\"\n\n[x]"),
+    //     "<p><a href=\"a\" title=\"&quot;\">x</a></p>",
+    //     "should support character escapes at the start of a title"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: a \"\\\"\"\n\n[x]"),
+    //     "<p><a href=\"a\" title=\"\"\">x</a></p>",
+    //     "should support double quoted titles"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: a '\"'\n\n[x]"),
+    //     "<p><a href=\"a\" title=\"&quot;\">x</a></p>",
+    //     "should support double quoted titles"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: a (\"\")\n\n[x]"),
+    //     "<p><a href=\"a\" title=\"&quot;\"\">x</a></p>",
+    //     "should support paren enclosed titles"
+    // );
+
+    assert_eq!(
+        micromark("[x]: a(()\n\n[x]"),
+        "<p>[x]: a(()</p>\n<p>[x]</p>",
+        "should not support more opening than closing parens in the destination"
+    );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: a(())\n\n[x]"),
+    //     "<p><a href=\"a(())\">x</a></p>",
+    //     "should support balanced opening and closing parens in the destination"
+    // );
+
+    assert_eq!(
+        micromark("[x]: a())\n\n[x]"),
+        "<p>[x]: a())</p>\n<p>[x]</p>",
+        "should not support more closing than opening parens in the destination"
+    );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: a  \t\n\n[x]"),
+    //     "<p><a href=\"a\">x</a></p>",
+    //     "should support trailing whitespace after a destination"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: a \"\"X \t\n\n[x]"),
+    //     "<p><a href=\"a\" title=\"\"X>x</a></p>",
+    //     "should support trailing whitespace after a destination"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[&amp;&copy;&]: example.com/&amp;&copy;& \"&amp;&copy;&\"\n\n[&amp;&copy;&]"),
+    //     "<p><a href=\"example.com/&amp;%C2%A9&amp;\" title=\"&amp;©&amp;\">&amp;©&amp;</a></p>",
+    //     "should support character references in definitions"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]:\nexample.com\n\n[x]"),
+    //     "<p><a href=\"example.com\">x</a></p>",
+    //     "should support a line ending before a destination"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: \t\nexample.com\n\n[x]"),
+    //     "<p><a href=\"example.com\">x</a></p>",
+    //     "should support whitespace before a destination"
+    // );
+
+    // See: <https://github.com/commonmark/commonmark.js/issues/192>
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[x]: <> \"\"\n[][x]"),
+    //     "<p><a href=\"\"></a></p>",
+    //     "should ignore an empty title"
+    // );
+
+    assert_eq!(
+        micromark_with_options("[a]\n\n[a]: <b<c>", DANGER),
+        "<p>[a]</p>\n<p>[a]: &lt;b<c></p>",
+        "should not support a less than in an enclosed destination"
+    );
+
+    assert_eq!(
+        micromark("[a]\n\n[a]: b(c"),
+        "<p>[a]</p>\n<p>[a]: b(c</p>",
+        "should not support an extra left paren (`(`) in a raw destination"
+    );
+
+    assert_eq!(
+        micromark("[a]\n\n[a]: b)c"),
+        "<p>[a]</p>\n<p>[a]: b)c</p>",
+        "should not support an extra right paren (`)`) in a raw destination"
+    );
+
+    assert_eq!(
+        micromark("[a]\n\n[a]: b)c"),
+        "<p>[a]</p>\n<p>[a]: b)c</p>",
+        "should not support an extra right paren (`)`) in a raw destination"
+    );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[a]\n\n[a]: a(1(2(3(4()))))b"),
+    //     "<p><a href=\"a(1(2(3(4()))))b\">a</a></p>\n",
+    //     "should support 4 or more sets of parens in a raw destination (link resources don’t)"
+    // );
+
+    assert_eq!(
+        micromark("[a]\n\n[a]: aaa)"),
+        "<p>[a]</p>\n<p>[a]: aaa)</p>",
+        "should not support a final (unbalanced) right paren in a raw destination"
+    );
+
+    assert_eq!(
+        micromark("[a]\n\n[a]: aaa) \"a\""),
+        "<p>[a]</p>\n<p>[a]: aaa) &quot;a&quot;</p>",
+        "should not support a final (unbalanced) right paren in a raw destination “before” a title"
+    );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark(" [a]: b \"c\"\n  [d]: e\n   [f]: g \"h\"\n    [i]: j\n\t[k]: l (m)\n\t n [k] o"),
+    //     "<p>n <a href=\"l\" title=\"m\">k</a> o</p>",
+    //     "should support subsequent indented definitions"
+    // );
+
+    // To do: link (reference).
+    // assert_eq!(
+    //     micromark("[a\n  b]: c\n\n[a\n  b]"),
+    //     "<p><a href=\"c\">a\nb</a></p>",
+    //     "should support line prefixes in definition labels"
+    // );
+
+    assert_eq!(
+        micromark("[a]: )\n\n[a]"),
+        "<p>[a]: )</p>\n<p>[a]</p>",
+        "should not support definitions w/ only a closing paren as a raw destination"
+    );
+
+    assert_eq!(
+        micromark("[a]: )b\n\n[a]"),
+        "<p>[a]: )b</p>\n<p>[a]</p>",
+        "should not support definitions w/ closing paren + more text as a raw destination"
+    );
+
+    assert_eq!(
+        micromark("[a]: b)\n\n[a]"),
+        "<p>[a]: b)</p>\n<p>[a]</p>",
+        "should not support definitions w/ text + a closing paren as a raw destination"
+    );
+
+    // To do: support turning off things.
+    // assert_eq!(
+    //   micromark("[foo]: /url \"title\"", {
+    //     extensions: [{disable: {null: ["definition"]}}]
+    //   }),
+    //   "<p>[foo]: /url &quot;title&quot;</p>",
+    //   "should support turning off definitions"
+    // );
+}