From 52c995659dab6c224ce5f55b53970cfa23f60bc5 Mon Sep 17 00:00:00 2001
From: Eduard Urbach <admin@akyoto.dev>
Date: Tue, 2 Apr 2024 19:48:35 +0200
Subject: [PATCH] Implemented text formatting

---
 README.md      |  8 +++++---
 Render.go      | 50 +++++++++++++++++++++++++++++++++++++++-----------
 Render_test.go | 13 +++++++++++++
 3 files changed, 57 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md
index a5be041..089dff5 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,8 @@ html := markdown.Render("# Header")
 PASS: TestEmpty
 PASS: TestParagraph
 PASS: TestHeader
+PASS: TestItalic
+PASS: TestBold
 PASS: TestLink
 PASS: TestList
 PASS: TestTables
@@ -45,9 +47,9 @@ coverage: 100.0% of statements
 ## Benchmarks
 
 ```
-BenchmarkSmall-12        8846642               135.5 ns/op            32 B/op          1 allocs/op
-BenchmarkMedium-12        711596              1465 ns/op             512 B/op          1 allocs/op
-BenchmarkLarge-12         279253              3874 ns/op            2560 B/op          2 allocs/op
+BenchmarkSmall-12        8109500               145.1 ns/op            32 B/op          1 allocs/op
+BenchmarkMedium-12        556713              1906 ns/op             512 B/op          1 allocs/op
+BenchmarkLarge-12         218116              4588 ns/op            2560 B/op          2 allocs/op
 ```
 
 ## License
diff --git a/Render.go b/Render.go
index 3c03851..6679a00 100644
--- a/Render.go
+++ b/Render.go
@@ -122,18 +122,20 @@ func (r *renderer) processLine(line string) {
 			return
 		}
 
-		line = strings.TrimSpace(line[1:])
+		if len(line) > 1 && line[1] == ' ' {
+			line = line[2:]
 
-		if r.listLevel == 0 {
-			r.WriteString("<ul>")
-			r.listLevel++
+			if r.listLevel == 0 {
+				r.WriteString("<ul>")
+				r.listLevel++
+			}
+
+			r.WriteString("<li>")
+			r.writeText(line)
+			r.WriteString("</li>")
+			return
 		}
 
-		r.WriteString("<li>")
-		r.writeText(line)
-		r.WriteString("</li>")
-		return
-
 	case '`':
 		if strings.HasPrefix(line, "```") {
 			language := line[3:]
@@ -255,12 +257,14 @@ func (r *renderer) writeText(markdown string) {
 		textStart   = -1
 		textEnd     = -1
 		urlStart    = -1
-		parentheses = 0
 		codeStart   = -1
+		emStart     = -1
+		strongStart = -1
+		parentheses = 0
 	)
 
 	for {
-		if i == len(markdown) {
+		if i >= len(markdown) {
 			r.WriteString(html.EscapeString(markdown[tokenStart:]))
 			return
 		}
@@ -315,6 +319,30 @@ func (r *renderer) writeText(markdown string) {
 				tokenStart = i
 				codeStart = i + 1
 			}
+
+		case '*', '_':
+			if i == emStart {
+				strongStart = i + 1
+				emStart = -1
+			} else if strongStart != -1 {
+				r.WriteString("<strong>")
+				r.WriteString(html.EscapeString(markdown[strongStart:i]))
+				r.WriteString("</strong>")
+				strongStart = -1
+
+				i++
+				tokenStart = i + 1
+			} else if emStart != -1 {
+				r.WriteString("<em>")
+				r.WriteString(html.EscapeString(markdown[emStart:i]))
+				r.WriteString("</em>")
+				emStart = -1
+				tokenStart = i + 1
+			} else {
+				r.WriteString(html.EscapeString(markdown[tokenStart:i]))
+				tokenStart = i
+				emStart = i + 1
+			}
 		}
 
 		i++
diff --git a/Render_test.go b/Render_test.go
index bc21e72..33c2be7 100644
--- a/Render_test.go
+++ b/Render_test.go
@@ -29,6 +29,16 @@ func TestHeader(t *testing.T) {
 	assert.Equal(t, markdown.Render("###### Header"), "<h6>Header</h6>")
 }
 
+func TestItalic(t *testing.T) {
+	assert.Equal(t, markdown.Render("*italic*"), "<p><em>italic</em></p>")
+	assert.Equal(t, markdown.Render("_italic_"), "<p><em>italic</em></p>")
+}
+
+func TestBold(t *testing.T) {
+	assert.Equal(t, markdown.Render("**bold**"), "<p><strong>bold</strong></p>")
+	assert.Equal(t, markdown.Render("__bold__"), "<p><strong>bold</strong></p>")
+}
+
 func TestLink(t *testing.T) {
 	assert.Equal(t, markdown.Render("[text](https://example.com/)"), "<p><a href=\"https://example.com/\">text</a></p>")
 	assert.Equal(t, markdown.Render("[text](https://example.com/"), "<p>[text](https://example.com/</p>")
@@ -42,6 +52,7 @@ func TestList(t *testing.T) {
 	assert.Equal(t, markdown.Render("- Entry"), "<ul><li>Entry</li></ul>")
 	assert.Equal(t, markdown.Render("- Entry 1\n- Entry 2"), "<ul><li>Entry 1</li><li>Entry 2</li></ul>")
 	assert.Equal(t, markdown.Render("- Entry 1\n- Entry 2\n- Entry 3"), "<ul><li>Entry 1</li><li>Entry 2</li><li>Entry 3</li></ul>")
+	assert.Equal(t, markdown.Render("-"), "<p>-</p>")
 }
 
 func TestTables(t *testing.T) {
@@ -77,6 +88,8 @@ func TestCombined(t *testing.T) {
 	assert.Equal(t, markdown.Render("# Title\n\n- Entry 1\n- Entry 2\n\nText."), "<h1>Title</h1><ul><li>Entry 1</li><li>Entry 2</li></ul><p>Text.</p>")
 	assert.Equal(t, markdown.Render("- Entry\n# Header"), "<ul><li>Entry</li></ul><h1>Header</h1>")
 	assert.Equal(t, markdown.Render("> - Entry\n> # Header"), "<blockquote><ul><li>Entry</li></ul><h1>Header</h1></blockquote>")
+	assert.Equal(t, markdown.Render("> **bold** and *italic* text."), "<blockquote><p><strong>bold</strong> and <em>italic</em> text.</p></blockquote>")
+	assert.Equal(t, markdown.Render("> __bold__ and _italic_ text."), "<blockquote><p><strong>bold</strong> and <em>italic</em> text.</p></blockquote>")
 }
 
 func TestSecurity(t *testing.T) {