:hammer::white_check_mark: Add html2markdown unit tests.

A tiny refactoring to make HTML 2 markdown conversion testable.
Add some unit tests to check the behavior of the now used HTML2Markdown library.
There are some differences compared to the old pixel418/markdownify library.

3 files changed, 208 insertions, 9 deletions

diff --git a/include/markdown.php b/include/markdown.php
index 39569a0f6..55ae528a4 100644
--- a/include/markdown.php
+++ b/include/markdown.php
@@ -453,15 +453,24 @@ function bb2diaspora_itembody($item, $force_update = false, $have_channel = fals
 	return html_entity_decode($body);
 }
 
+/**
+ * @brief Prepare bbcode for Diaspora.
+ *
+ * @hooks bb2diaspora
+ *    * \e string The prepared text for diaspora.
+ *
+ * @param string $Text bbcode
+ * @param boolean $preserve_nl (default false) preserve new lines
+ * @param boolean $fordiaspora (default true, but unused)
+ * @return string
+ */
 function bb2diaspora($Text, $preserve_nl = false, $fordiaspora = true) {
 
 	// Re-enabling the converter again.
 	// The bbcode parser now handles youtube-links (and the other stuff) correctly.
 	// Additionally the html code is now fixed so that lists are now working.
 
-	/*
-	 * Transform #tags, strip off the [url] and replace spaces with underscore
-	 */
+	// Transform #tags, strip off the [url] and replace spaces with underscore
 	$Text = preg_replace_callback('/#\[([zu])rl\=(\w+.*?)\](\w+.*?)\[\/[(zu)]rl\]/i', create_function('$match',
 		'return \'#\'. str_replace(\' \', \'_\', $match[3]);'
 	), $Text);
@@ -473,7 +482,6 @@ function bb2diaspora($Text, $preserve_nl = false, $fordiaspora = true) {
 	// strip map tags, as the rendering is performed in bbcode() and the resulting output
 	// is not compatible with Diaspora (at least in the case of openstreetmap and probably
 	// due to the inclusion of an html iframe)
-
 	$Text = preg_replace("/\[map\=(.*?)\]/ism", '$1', $Text);
 	$Text = preg_replace("/\[map\](.*?)\[\/map\]/ism", '$1', $Text);
 
@@ -491,15 +499,12 @@ function bb2diaspora($Text, $preserve_nl = false, $fordiaspora = true) {
 	$Text = bbcode($Text, $preserve_nl, false);
 
 	// Markdownify does not preserve previously escaped html entities such as <> and &.
-
 	$Text = str_replace(array('&lt;','&gt;','&amp;'),array('&_lt_;','&_gt_;','&_amp_;'),$Text);
 
 	// Now convert HTML to Markdown
-	$md = new HtmlConverter();
-	$Text = $md->convert($Text);
+	$Text = html2markdown($Text);
 
 	// It also adds backslashes to our attempt at getting around the html entity preservation for some weird reason.
-
 	$Text = str_replace(array('&\\_lt\\_;','&\\_gt\\_;','&\\_amp\\_;'),array('&lt;','&gt;','&amp;'),$Text);
 
 	// If the text going into bbcode() has a plain URL in it, i.e.
@@ -516,7 +521,6 @@ function bb2diaspora($Text, $preserve_nl = false, $fordiaspora = true) {
 
 	// Remove any leading or trailing whitespace, as this will mess up
 	// the Diaspora signature verification and cause the item to disappear
-
 	$Text = trim($Text);
 
 	call_hooks('bb2diaspora', $Text);
@@ -563,3 +567,31 @@ function format_event_diaspora($ev) {
 
 	return $o;
 }
+
+/**
+ * @brief Convert a HTML text into Markdown.
+ *
+ * This function uses the library league/html-to-markdown for this task.
+ *
+ * If the HTML text can not get parsed it will return an empty string.
+ *
+ * @see HTMLToMarkdown
+ *
+ * @param string $html The HTML code to convert
+ * @return string Markdown representation of the given HTML text, empty on error
+ */
+function html2markdown(String $html) : String {
+	$markdown = '';
+	$converter = new HtmlConverter();
+
+	try {
+		$markdown = $converter->convert($html);
+	} catch (InvalidArgumentException $e) {
+		logger("Invalid HTML. HTMLToMarkdown library threw an exception.");
+	}
+
+	// The old html 2 markdown library "pixel418/markdownify": "^2.2",
+	//$md = new HtmlConverter();
+	//$markdown = $md->convert($Text);
+	return $markdown;
+}
diff --git a/tests/unit/includes/MarkdownTest.php b/tests/unit/includes/MarkdownTest.php
new file mode 100644
index 000000000..3026c633a
--- /dev/null
+++ b/tests/unit/includes/MarkdownTest.php
@@ -0,0 +1,149 @@
+<?php
+/*
+ * Copyright (c) 2017 Hubzilla
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to deal
+* in the Software without restriction, including without limitation the rights
+* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+* copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+* SOFTWARE.
+*/
+
+namespace Zotlabs\Tests\Unit\includes;
+
+use Zotlabs\Tests\Unit\UnitTestCase;
+use phpmock\phpunit\PHPMock;
+
+require_once 'include/markdown.php';
+
+/**
+ * @brief Unit Test case for markdown functions.
+ */
+class MarkdownTest extends UnitTestCase {
+	use PHPMock;
+
+	/**
+	 * @covers ::html2markdown
+	 * @dataProvider html2markdownProvider
+	 */
+	public function testHtml2markdown($html, $markdown) {
+		$this->assertEquals($markdown, html2markdown($html));
+	}
+
+	public function html2markdownProvider() {
+		return [
+				'empty text' => [
+						'',
+						''
+				],
+				'space and nbsp only' => [
+						' &nbsp;',
+						''
+				],
+				'strong, b, em, i, bib' => [
+						'<strong>strong</strong> <b>bold</b> <em>em</em> <i>italic</i>  <b>bo<i>italic</i>ld</b>',
+						'**strong** **bold** _em_ _italic_ **bo_italic_ld**'
+				],
+				'empty tags' => [
+						'text1 <b></b> text2 <i></i>',
+						'text1  text2'
+				],
+				'HTML entities, lt does not work' => [
+						'& gt > lt <',
+						'& gt > lt'
+				],
+				'escaped HTML entities' => [
+						'&amp; lt &lt; gt &gt;',
+						'& lt < gt >'
+				],
+				'our escaped HTML entities' => [
+						'&_lt_; &_gt_; &_amp_;',
+						'&\_lt\_; &\_gt\_; &\_amp\_;'
+				],
+				'linebreak' => [
+						"line1<br>line2\nline3",
+						"line1  \nline2 line3"
+				],
+				'headlines' => [
+						'<h1>header1</h1><h3>Header 3</h3>',
+						"header1\n=======\n\n### Header 3"
+				],
+				'unordered list' => [
+						'<ul><li>Item 1</li><li>Item 2</li><li>Item <b>3</b></li></ul>',
+						"- Item 1\n- Item 2\n- Item **3**"
+				],
+				'ordered list' => [
+						'<ol><li>Item 1</li><li>Item 2</li><li>Item <b>3</b></li></ol>',
+						"1. Item 1\n2. Item 2\n3. Item **3**"
+				],
+				'nested lists' => [
+						'<ul><li>Item 1<ol><li>Item 1a</li><li>Item <b>1b</b></ol></li><li>Item 2</li></ul>',
+						"- Item 1\n  1. Item 1a\n  2. Item **1b**\n- Item 2"
+				],
+				'img' => [
+						'<img src="/path/to/img.png" alt="alt text" title="title text">',
+						'![alt text](/path/to/img.png "title text")'
+				],
+				'link' => [
+						'<a href="http://hubzilla.org" title="Hubzilla">link</a>',
+						'[link](http://hubzilla.org "Hubzilla")'
+				],
+				'img link' => [
+						'<a href="http://hubzilla.org" title="Hubzilla"><img src="/img/hubzilla.png" alt="alt img text" title="img title"></a>',
+						'[![alt img text](/img/hubzilla.png "img title")](http://hubzilla.org "Hubzilla")'
+				],
+				'script' => [
+						"<script>alert('test');</script>",
+						"<script>alert('test');</script>"
+				],
+				'blockquote, issue #793' => [
+						'<blockquote>something</blockquote>blah',
+						"> something\n\nblah"
+				],
+				'code' => [
+						'<code>&lt;p&gt;HTML text&lt;/p&gt;</code>',
+						'`<p>HTML text</p>`'
+				],
+				'pre' => [
+						'<pre>   line with  spaces   </pre>',
+						'`   line with  spaces   `'
+				],
+				'div p' => [
+						'<div>div</div><div><p>p</p></div>',
+						"<div>div</div><div>p\n\n</div>"
+				]
+		];
+	}
+
+	/*public function testHtml2markdownException() {
+		//$this->expectException(\InvalidArgumentException::class);
+		// need to stub logger() for this to work
+		$this->assertEquals('', html2markdown('<<invalid'));
+	}*/
+
+/*	public function testBB2diasporaMardown() {
+		//stub bbcode() and return our HTML, we just need to test the HTML2Markdown library.
+		$html1 = 'test<b>bold</b><br><i>i</i><ul><li>li1</li><li>li2</li></ul><br>';
+		$bb1 = 'test';
+
+		// php-mock can not mock global functions which is called by a global function.
+		// If the calling function is in a namespace it does work.
+		$bbc = $this->getFunctionMock(__NAMESPACE__, "bbcode");
+		$bbc->expects($this->once())->willReturn('test<b>bold</b><br><i>i</i><ul><li>li1</li><li>li2</li></ul><br>');
+
+		$this->assertEquals($bb1, bb2diaspora($html1));
+	}
+*/
+}
\ No newline at end of file
diff --git a/tests/unit/includes/TextTest.php b/tests/unit/includes/TextTest.php
index e2c7cbb9a..4afa2b49b 100644
--- a/tests/unit/includes/TextTest.php
+++ b/tests/unit/includes/TextTest.php
@@ -11,6 +11,9 @@ use Zotlabs\Tests\Unit\UnitTestCase;
  */
 class TextTest extends UnitTestCase {
 
+	/**
+	 * @covers ::valid_email_regex
+	 */
 	public function testGoodEmail() {
 		$this->assertTrue(valid_email_regex('ken@spaz.org'));
 		$this->assertTrue(valid_email_regex('ken@restivo.org'));
@@ -18,11 +21,17 @@ class TextTest extends UnitTestCase {
 		$this->assertTrue(valid_email_regex('foo+nobody@hubzilla.org'));
 	}
 
+	/**
+	 * @covers ::valid_email_regex
+	 */
 	public function testBadEmail() {
 		$this->assertFalse(valid_email_regex('nobody!uses!these!any.more'));
 		$this->assertFalse(valid_email_regex('foo@bar@hubzilla.org'));
 	}
 
+	/**
+	 * @covers ::purify_html
+	 */
 	public function testPurifyHTML() {
 		// linebreaks
 		$htmlbr = 'first line<br />
@@ -46,6 +55,9 @@ empty line above';
 		$this->assertEquals('<ul><li>item1</li></ul>', purify_html('<ul data-accordion-menu-unknown><li>item1</li></ul>'));
 	}
 
+	/**
+	 * @covers ::purify_html
+	 */
 	public function testPurifyHTML_html() {
 		$this->assertEquals('<div id="id01"><p class="class01">ids und classes</p></div>', purify_html('<div id="id01"><p class="class01">ids und classes</p></div>'));
 		$this->assertEquals('<div><p>close missing tags</p></div>', purify_html('<div><p>close missing tags'));
@@ -59,6 +71,9 @@ empty line above';
 		$this->assertEquals('', purify_html('<iframe width="560" height="315" src="https://www.youtube.com/embed/kiNGx5oL7hk" frameborder="0" allowfullscreen></iframe>'));
 	}
 
+	/**
+	 * @covers ::purify_html
+	 */
 	public function testPurifyHTML_js() {
 		$this->assertEquals('<div></div>', purify_html('<div><img src="javascript:evil();" onload="evil();"></div>'));
 		$this->assertEquals('<a href="#">link</a>', purify_html('<a href="#" onclick="alert(\'xss\')">link</a>'));
@@ -66,6 +81,9 @@ empty line above';
 		$this->assertEquals('', purify_html('<script>alter("42")</script>'));
 	}
 
+	/**
+	 * @covers ::purify_html
+	 */
 	public function testPurifyHTML_css() {
 		$this->assertEquals('<p style="color:#FF0000;background-color:#fff;">red</p>', purify_html('<p style="color:red; background-color:#fff">red</p>'));
 		$this->assertEquals('<p>invalid color</p>', purify_html('<p style="color:invalid; background-color:#jjkkmm">invalid color</p>'));