added corner cases for comments.go in astbuilder package (#3134)

* added corner cases for comments.go in astbuilder package
* added corner cases to the comments
* updated test case

Co-authored-by: Bevan Arps <bevan.arps@microsoft.com>

v2/tools/generator/internal/astbuilder/comments.go

@@ -87,6 +87,9 @@ func AddComment(commentList *dst.Decorations, comment string) {
 
 // formatComment splits the supplied comment string up ready for use as a documentation comment
 func formatComment(comment string, width int) []string {
+	if comment == "" {
+		return []string{}
+	}
 	// Remove markdown bolding
 	text := strings.ReplaceAll(comment, "**", "")
 
@@ -122,6 +125,10 @@ func docCommentWrap(lines []string, width int) []string {
 func WordWrap(text string, width int) []string {
 	var result []string
 
+	if width == 0 && text == "" {
+		return []string{}
+	}
+
 	start := 0
 	for start < len(text) {
 		finish := findBreakPoint(text, start, width)

v2/tools/generator/internal/astbuilder/comments_test.go

@@ -38,6 +38,7 @@ func TestDocumentationCommentFormatting(t *testing.T) {
 		{"**foo**\nbar", []string{"foo", "bar"}},
 		{"foo\n**bar**", []string{"foo", "bar"}},
 		{"foo\n**bar**\nbaz", []string{"foo", "bar", "baz"}},
+		{"", []string{}},
 		// Expect long lines to be wrapped
 		{
 			"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
@@ -70,6 +71,8 @@ func TestWordWrap(t *testing.T) {
 		{"this is a simple line of text", 16, []string{"this is a simple ", "line of text"}},
 		{"this is a simple line of text", 20, []string{"this is a simple ", "line of text"}},
 		{"this is a simple line of text", 21, []string{"this is a simple line ", "of text"}},
+		{"", 0, []string{}},
+		{"this is a sample text", 0, []string{"this ", "is ", "a ", "sample ", "text"}},
 	}
 
 	for _, c := range cases {