From 8ea7b1c86cbf04e11f99df702c954ce18ead52c3 Mon Sep 17 00:00:00 2001
From: Brandon Wilson <bwilson@abre.io>
Date: Wed, 11 Aug 2021 21:27:32 -0400
Subject: [PATCH] Optionally Preserving New Lines (#115)

---
 ansi/paragraph.go               |  2 +-
 ansi/renderer.go                |  9 +++++----
 glamour.go                      |  8 ++++++++
 glamour_test.go                 | 30 ++++++++++++++++++++++++++++++
 testdata/preserved_newline.in   |  4 ++++
 testdata/preserved_newline.test |  5 +++++
 6 files changed, 53 insertions(+), 5 deletions(-)
 create mode 100644 testdata/preserved_newline.in
 create mode 100644 testdata/preserved_newline.test

diff --git a/ansi/paragraph.go b/ansi/paragraph.go
index 71e0725..0d3f99a 100644
--- a/ansi/paragraph.go
+++ b/ansi/paragraph.go
@@ -38,7 +38,7 @@ func (e *ParagraphElement) Finish(w io.Writer, ctx RenderContext) error {
 	mw := NewMarginWriter(ctx, w, rules)
 	if len(strings.TrimSpace(bs.Current().Block.String())) > 0 {
 		flow := wordwrap.NewWriter(int(bs.Width(ctx)))
-		flow.KeepNewlines = false
+		flow.KeepNewlines = ctx.options.PreserveNewLines
 		_, _ = flow.Write(bs.Current().Block.Bytes())
 		flow.Close()
 
diff --git a/ansi/renderer.go b/ansi/renderer.go
index ddadbb7..55444ca 100644
--- a/ansi/renderer.go
+++ b/ansi/renderer.go
@@ -15,10 +15,11 @@ import (
 
 // Options is used to configure an ANSIRenderer.
 type Options struct {
-	BaseURL      string
-	WordWrap     int
-	ColorProfile termenv.Profile
-	Styles       StyleConfig
+	BaseURL          string
+	WordWrap         int
+	PreserveNewLines bool
+	ColorProfile     termenv.Profile
+	Styles           StyleConfig
 }
 
 // ANSIRenderer renders markdown content as ANSI escaped sequences.
diff --git a/glamour.go b/glamour.go
index 7b4a14c..048d45a 100644
--- a/glamour.go
+++ b/glamour.go
@@ -185,6 +185,14 @@ func WithWordWrap(wordWrap int) TermRendererOption {
 	}
 }
 
+// WithWordWrap sets a TermRenderer's word wrap.
+func WithPreservedNewLines() TermRendererOption {
+	return func(tr *TermRenderer) error {
+		tr.ansiOptions.PreserveNewLines = true
+		return nil
+	}
+}
+
 // WithEmoji sets a TermRenderer's emoji rendering.
 func WithEmoji() TermRendererOption {
 	return func(tr *TermRenderer) error {
diff --git a/glamour_test.go b/glamour_test.go
index 52f59a5..7f36d21 100644
--- a/glamour_test.go
+++ b/glamour_test.go
@@ -113,6 +113,36 @@ func TestWithEmoji(t *testing.T) {
 	}
 }
 
+func TestWithPreservedNewLines(t *testing.T) {
+	r, err := NewTermRenderer(
+		WithPreservedNewLines(),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	in, err := ioutil.ReadFile("testdata/preserved_newline.in")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	b, err := r.Render(string(in))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// verify
+	td, err := ioutil.ReadFile("testdata/preserved_newline.test")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !bytes.Equal(td, []byte(b)) {
+		t.Errorf("Rendered output doesn't match!\nExpected: `\n%s`\nGot: `\n%s`\n",
+			string(td), b)
+	}
+}
+
 func TestStyles(t *testing.T) {
 	_, err := NewTermRenderer(
 		WithAutoStyle(),
diff --git a/testdata/preserved_newline.in b/testdata/preserved_newline.in
new file mode 100644
index 0000000..f36a086
--- /dev/null
+++ b/testdata/preserved_newline.in
@@ -0,0 +1,4 @@
+Preserving line breaks will ensure
+that this text displays on two separate lines
+
+While this text appears on one line, it will wrap when the text meets the renderer's default value of 80 characters
\ No newline at end of file
diff --git a/testdata/preserved_newline.test b/testdata/preserved_newline.test
new file mode 100644
index 0000000..54f4f7c
--- /dev/null
+++ b/testdata/preserved_newline.test
@@ -0,0 +1,5 @@
+Preserving line breaks will ensure                                              
+that this text displays on two separate lines                                   
+                                                                                
+While this text appears on one line, it will wrap when the text meets the       
+renderer's default value of 80 characters