Create seperate page getter

pkg/app/pagewriter/static_pages.go

@@ -21,7 +21,7 @@ var defaultRobotsTxt []byte
 
 // staticPageWriter is used to write static pages.
 type staticPageWriter struct {
-	pages           map[string][]byte
+	pageGetter      *pageGetter
 	errorPageWriter *errorPageWriter
 }
 
@@ -32,13 +32,7 @@ func (s *staticPageWriter) WriteRobotsTxt(rw http.ResponseWriter, req *http.Requ
 
 // writePage writes the content of the page to the response writer.
 func (s *staticPageWriter) writePage(rw http.ResponseWriter, req *http.Request, pageName string) {
-	content, ok := s.pages[pageName]
-	if !ok {
-		// If the page isn't regiested, something went wrong and there is a bug.
-		// Tests should make sure this code path is never hit.
-		panic(fmt.Sprintf("Static page %q not found", pageName))
-	}
-	_, err := rw.Write(content)
+	_, err := rw.Write(s.pageGetter.getPage(pageName))
 	if err != nil {
 		logger.Printf("Error writing %q: %v", pageName, err)
 		scope := middlewareapi.GetRequestScope(req)
@@ -52,13 +46,13 @@ func (s *staticPageWriter) writePage(rw http.ResponseWriter, req *http.Request,
 }
 
 func newStaticPageWriter(customDir string, errorWriter *errorPageWriter) (*staticPageWriter, error) {
-	pages, err := loadStaticPages(customDir)
+	pageGetter, err := loadStaticPages(customDir)
 	if err != nil {
 		return nil, fmt.Errorf("could not load static pages: %v", err)
 	}
 
 	return &staticPageWriter{
-		pages:           pages,
+		pageGetter:      pageGetter,
 		errorPageWriter: errorWriter,
 	}, nil
 }
@@ -68,31 +62,57 @@ func newStaticPageWriter(customDir string, errorWriter *errorPageWriter) (*stati
 // instead.
 // Statis files include:
 // - robots.txt
-func loadStaticPages(customDir string) (map[string][]byte, error) {
-	pages := make(map[string][]byte)
+func loadStaticPages(customDir string) (*pageGetter, error) {
+	pages := newPageGetter(customDir)
 
-	if err := addStaticPage(pages, customDir, robotsTxtName, defaultRobotsTxt); err != nil {
+	if err := pages.addPage(robotsTxtName, defaultRobotsTxt); err != nil {
 		return nil, fmt.Errorf("could not add robots.txt: %v", err)
 	}
 
 	return pages, nil
 }
 
-// addStaticPage tries to load the named file from the custom directory.
-// If no custom directory is provided, the default content is used instead.
-func addStaticPage(pages map[string][]byte, customDir, fileName string, defaultContent []byte) error {
-	filePath := filepath.Join(customDir, fileName)
-	if customDir != "" && isFile(filePath) {
+// pageGetter is used to load and read page content for static pages.
+type pageGetter struct {
+	pages map[string][]byte
+	dir   string
+}
+
+// newPageGetter creates a new page getter for the custom directory.
+func newPageGetter(customDir string) *pageGetter {
+	return &pageGetter{
+		pages: make(map[string][]byte),
+		dir:   customDir,
+	}
+}
+
+// addPage loads a new page into the pageGetter.
+// If the given file name does not exist in the custom directory, the default
+// content will be used instead.
+func (p *pageGetter) addPage(fileName string, defaultContent []byte) error {
+	filePath := filepath.Join(p.dir, fileName)
+	if p.dir != "" && isFile(filePath) {
 		content, err := os.ReadFile(filePath)
 		if err != nil {
 			return fmt.Errorf("could not read file: %v", err)
 		}
 
-		pages[fileName] = content
+		p.pages[fileName] = content
 		return nil
 	}
 
 	// No custom content defined, use the default.
-	pages[fileName] = defaultContent
+	p.pages[fileName] = defaultContent
 	return nil
 }
+
+// getPage returns the page content for a given page.
+func (p *pageGetter) getPage(name string) []byte {
+	content, ok := p.pages[name]
+	if !ok {
+		// If the page isn't registered, something went wrong and there is a bug.
+		// Tests should make sure this code path is never hit.
+		panic(fmt.Sprintf("Static page %q not found", name))
+	}
+	return content
+}

pkg/app/pagewriter/static_pages_test.go

@@ -16,7 +16,7 @@ import (
 
 var _ = Describe("Static Pages", func() {
 	var customDir string
-	const customRobots = "I AM A ROBOT!!!"
+	const customRobots = "User-agent: *\nAllow: /\n"
 	var errorPage *errorPageWriter
 	var request *http.Request
 
@@ -110,8 +110,8 @@ var _ = Describe("Static Pages", func() {
 				It("Loads the custom content", func() {
 					pages, err := loadStaticPages(customDir)
 					Expect(err).ToNot(HaveOccurred())
-					Expect(pages).To(HaveLen(1))
-					Expect(pages).To(HaveKeyWithValue(robotsTxtName, []byte(customRobots)))
+					Expect(pages.pages).To(HaveLen(1))
+					Expect(pages.getPage(robotsTxtName)).To(BeEquivalentTo(customRobots))
 				})
 			})
 
@@ -122,8 +122,8 @@ var _ = Describe("Static Pages", func() {
 
 					pages, err := loadStaticPages(customDir)
 					Expect(err).ToNot(HaveOccurred())
-					Expect(pages).To(HaveLen(1))
-					Expect(pages).To(HaveKeyWithValue(robotsTxtName, defaultRobotsTxt))
+					Expect(pages.pages).To(HaveLen(1))
+					Expect(pages.getPage(robotsTxtName)).To(BeEquivalentTo(defaultRobotsTxt))
 				})
 			})
 		})
@@ -132,8 +132,8 @@ var _ = Describe("Static Pages", func() {
 			It("Loads the default content", func() {
 				pages, err := loadStaticPages("")
 				Expect(err).ToNot(HaveOccurred())
-				Expect(pages).To(HaveLen(1))
-				Expect(pages).To(HaveKeyWithValue(robotsTxtName, defaultRobotsTxt))
+				Expect(pages.pages).To(HaveLen(1))
+				Expect(pages.getPage(robotsTxtName)).To(BeEquivalentTo(defaultRobotsTxt))
 			})
 		})
 	})