[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

@@ -28,7 +28,10 @@ import (
 	"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))
@@ -48,7 +51,6 @@ func (f *formatter) FromMarkdown(ctx context.Context, md string, mentions []*gts
 		m.Add("text/html", &html.Minifier{
 			KeepEndTags: true,
 			KeepQuotes:  true,
-			KeepWhitespace: true,
 		})
 	}
 

internal/text/markdown_test.go

@@ -61,6 +61,10 @@ const (
 	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))
 }