Add configuration to render line breaks as <br> or not

tests/fixtures/markdowns.js

@@ -48,10 +48,13 @@ const checkboxes = `
 
 const smartQuotes = 'This is a "QUOTE".'
 
+const breaks = 'This is the first line.\nThis is the second line.'
+
 export default {
   basic,
   codeblock,
   katex,
   checkboxes,
-  smartQuotes
+  smartQuotes,
+  breaks
 }

tests/lib/markdown-test.js

@@ -34,3 +34,12 @@ test('Markdown.render() should text with quotes correctly', t => {
   const renderedNonSmartQuotes = newmd.render(markdownFixtures.smartQuotes)
   t.snapshot(renderedNonSmartQuotes)
 })
+
+test('Markdown.render() should render line breaks correctly', t => {
+  const renderedBreaks = md.render(markdownFixtures.breaks)
+  t.snapshot(renderedBreaks)
+
+  const newmd = new Markdown({ breaks: false })
+  const renderedNonBreaks = newmd.render(markdownFixtures.breaks)
+  t.snapshot(renderedNonBreaks)
+})

tests/lib/snapshots/markdown-test.js.md

@@ -73,4 +73,18 @@ Generated by [AVA](https://ava.li).
 > Snapshot 2
 
     `<p data-line="0">This is a &quot;QUOTE&quot;.</p>␊
+    
+
+## Markdown.render() should render line breaks correctly
+
+> Snapshot 1
+
+    `<p data-line="0">This is the first line.<br />␊
+    This is the second line.</p>␊
     `
+
+> Snapshot 2
+
+    `<p data-line="0">This is the first line.␊
+    This is the second line.</p>␊
+    `