Optionally Preserving New Lines (#115)

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()
 

ansi/renderer.go

@@ -17,6 +17,7 @@ import (
 type Options struct {
 	BaseURL          string
 	WordWrap         int
+	PreserveNewLines bool
 	ColorProfile     termenv.Profile
 	Styles           StyleConfig
 }

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 {

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(),

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

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