accept several urls, fix tests, remove unused book struct

book/chapter.go

@@ -9,6 +9,10 @@ type chapter struct {
 	config      *ScrapeConfig
 }
 
+func NewEmptyChapter() chapter {
+	return chapter{"", "", "", "", []chapter{}, NewScrapeConfigNoInclude()}
+}
+
 func NewChapter(body, name, author, content string, subChapters []chapter, config *ScrapeConfig) chapter {
 	return chapter{body, name, author, content, subChapters, config}
 }
@@ -21,6 +25,10 @@ func (c chapter) Name() string {
 	return c.name
 }
 
+func (c *chapter) SetName(name string) {
+	c.name = name
+}
+
 func (c chapter) Author() string {
 	return c.author
 }
@@ -32,3 +40,7 @@ func (c chapter) Content() string {
 func (c chapter) SubChapters() []chapter {
 	return c.subChapters
 }
+
+func (c *chapter) AddSubChapter(newChapter chapter) {
+	c.subChapters = append(c.subChapters, newChapter)
+}