From 79fb8bad04662bfb5aa8990afeba4c134eb06201 Mon Sep 17 00:00:00 2001
From: tobi <31960611+tsmethurst@users.noreply.github.com>
Date: Fri, 26 Aug 2022 13:28:06 +0200
Subject: [PATCH] [feature] Allow footnotes in markdown, use `<br>` instead of
 `\n` (#767)

* allow markdown footnotes + hard line breaks

* don't keep whitespace w/minify (unnecessary now)

* test markdown a bit more
---
 internal/text/markdown.go      | 12 +++++++-----
 internal/text/markdown_test.go | 16 +++++++++++++++-
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/internal/text/markdown.go b/internal/text/markdown.go
index 8952b99d6..13fb93378 100644
--- a/internal/text/markdown.go
+++ b/internal/text/markdown.go
@@ -28,7 +28,10 @@
 	"github.com/tdewolff/minify/v2/html"
 )
 
-var m *minify.M
+var (
+	bfExtensions = blackfriday.CommonExtensions | blackfriday.HardLineBreak | blackfriday.Footnotes
+	m            *minify.M
+)
 
 func (f *formatter) FromMarkdown(ctx context.Context, md string, mentions []*gtsmodel.Mention, tags []*gtsmodel.Tag) string {
 	// format tags nicely
@@ -38,7 +41,7 @@ func (f *formatter) FromMarkdown(ctx context.Context, md string, mentions []*gts
 	content = f.ReplaceMentions(ctx, content, mentions)
 
 	// parse markdown
-	contentBytes := blackfriday.Run([]byte(content))
+	contentBytes := blackfriday.Run([]byte(content), blackfriday.WithExtensions(bfExtensions))
 
 	// clean anything dangerous out of it
 	content = SanitizeHTML(string(contentBytes))
@@ -46,9 +49,8 @@ func (f *formatter) FromMarkdown(ctx context.Context, md string, mentions []*gts
 	if m == nil {
 		m = minify.New()
 		m.Add("text/html", &html.Minifier{
-			KeepEndTags:    true,
-			KeepQuotes:     true,
-			KeepWhitespace: true,
+			KeepEndTags: true,
+			KeepQuotes:  true,
 		})
 	}
 
diff --git a/internal/text/markdown_test.go b/internal/text/markdown_test.go
index af4a4fef6..3e156f43e 100644
--- a/internal/text/markdown_test.go
+++ b/internal/text/markdown_test.go
@@ -56,11 +56,15 @@
 	mdWithHTML                      = "# Title\n\nHere's a simple text in markdown.\n\nHere's a <a href=\"https://example.org\">link</a>.\n\nHere's an image: <img src=\"https://gts.superseriousbusiness.org/assets/logo.png\" alt=\"The GoToSocial sloth logo.\" width=\"500\" height=\"600\">"
 	mdWithHTMLExpected              = "<h1>Title</h1><p>Here’s a simple text in markdown.</p><p>Here’s a <a href=\"https://example.org\" rel=\"nofollow noreferrer noopener\" target=\"_blank\">link</a>.</p><p>Here’s an image: <img src=\"https://gts.superseriousbusiness.org/assets/logo.png\" alt=\"The GoToSocial sloth logo.\" width=\"500\" height=\"600\" crossorigin=\"anonymous\"></p>"
 	mdWithCheekyHTML                = "# Title\n\nHere's a simple text in markdown.\n\nHere's a cheeky little script: <script>alert(ahhhh)</script>"
-	mdWithCheekyHTMLExpected        = "<h1>Title</h1><p>Here’s a simple text in markdown.</p><p>Here’s a cheeky little script: </p>"
+	mdWithCheekyHTMLExpected        = "<h1>Title</h1><p>Here’s a simple text in markdown.</p><p>Here’s a cheeky little script:</p>"
 	mdWithHashtagInitial            = "#welcome #Hashtag"
 	mdWithHashtagInitialExpected    = "<p><a href=\"http://localhost:8080/tags/welcome\" class=\"mention hashtag\" rel=\"tag nofollow noreferrer noopener\" target=\"_blank\">#<span>welcome</span></a> <a href=\"http://localhost:8080/tags/Hashtag\" class=\"mention hashtag\" rel=\"tag nofollow noreferrer noopener\" target=\"_blank\">#<span>Hashtag</span></a></p>"
 	mdCodeBlockWithNewlines         = "some code coming up\n\n```\n\n\n\n```\nthat was some code"
 	mdCodeBlockWithNewlinesExpected = "<p>some code coming up</p><pre><code>\n\n\n</code></pre><p>that was some code</p>"
+	mdWithFootnote                  = "fox mulder,fbi.[^1]\n\n[^1]: federated bureau of investigation"
+	mdWithFootnoteExpected          = "<p>fox mulder,fbi.<sup id=\"fnref:1\"><a href=\"#fn:1\" rel=\"nofollow noreferrer\">1</a></sup></p><div><hr><ol><li id=\"fn:1\">federated bureau of investigation<br></li></ol></div>"
+	mdWithBlockQuote                = "get ready, there's a block quote coming:\n\n>line1\n>line2\n>\n>line3\n\n"
+	mdWithBlockQuoteExpected        = "<p>get ready, there’s a block quote coming:</p><blockquote><p>line1<br>line2</p><p>line3</p></blockquote>"
 )
 
 type MarkdownTestSuite struct {
@@ -119,6 +123,16 @@ func (suite *MarkdownTestSuite) TestParseCodeBlockWithNewlines() {
 	suite.Equal(mdCodeBlockWithNewlinesExpected, s)
 }
 
+func (suite *MarkdownTestSuite) TestParseWithFootnote() {
+	s := suite.formatter.FromMarkdown(context.Background(), mdWithFootnote, nil, nil)
+	suite.Equal(mdWithFootnoteExpected, s)
+}
+
+func (suite *MarkdownTestSuite) TestParseWithBlockquote() {
+	s := suite.formatter.FromMarkdown(context.Background(), mdWithBlockQuote, nil, nil)
+	suite.Equal(mdWithBlockQuoteExpected, s)
+}
+
 func TestMarkdownTestSuite(t *testing.T) {
 	suite.Run(t, new(MarkdownTestSuite))
 }