commit 00885b8e246aa50062e335de64c09b7a7964cfef
Author: Nhân <hi@imnhan.com>
Date:   Sun Jul 9 16:58:39 2023 +0700

    delete orphaned generated files

diff --git a/main.go b/main.go
index 909c968..ebbf72c 100644
--- a/main.go
+++ b/main.go
@@ -84,6 +84,8 @@ func regenerate(fsys writablefs.FS) {
 		return
 	}
 
+	generatedFiles := make(map[string]bool)
+
 	// Sort articles, newest first
 	sort.Slice(articles, func(i int, j int) bool {
 		return articles[i].PostedAt.Compare(articles[j].PostedAt) > 0
@@ -111,11 +113,13 @@ func regenerate(fsys writablefs.FS) {
 	for _, a := range articles {
 		fmt.Println(">", a.Path, "-", a.Title)
 		a.WriteHtmlFile(&site, articlesInNav, startYear)
+		generatedFiles[a.WebPath] = true
 	}
 	fmt.Printf("Processed %d articles\n", len(articles))
 
 	if site.GenerateHome {
 		WriteHomePage(fsys, site, articlesInFeed, articlesInNav, startYear)
+		generatedFiles["index.html"] = true
 		fmt.Println("Generated index.html")
 	}
 
@@ -123,7 +127,11 @@ func regenerate(fsys writablefs.FS) {
 		FEED_PATH,
 		generateFeed(site, articlesInFeed, site.HomePath+FEED_PATH),
 	)
+	generatedFiles[FEED_PATH] = true
 	fmt.Println("Generated", FEED_PATH)
+
+	DeleteOldGeneratedFiles(fsys, generatedFiles)
+	WriteManifest(fsys, generatedFiles)
 }
 
 type SiteMetadata struct {
diff --git a/makesite.go b/makesite.go
index ac9b60d..af438ac 100644
--- a/makesite.go
+++ b/makesite.go
@@ -16,11 +16,13 @@
 var defaultTheme embed.FS
 
 func makeSite(path string, meta SiteMetadata) error {
+	// Create web root dir
 	err := os.MkdirAll(path, 0755)
 	if err != nil {
 		return fmt.Errorf("make site: %w", err)
 	}
 
+	// Create site metadata file
 	metaFilePath := filepath.Join(path, SITE_FILENAME)
 	metaFile, err := os.Create(metaFilePath)
 	if err != nil {
@@ -34,7 +36,9 @@ func makeSite(path string, meta SiteMetadata) error {
 		return fmt.Errorf("write site metadata: %w", err)
 	}
 
+	// Copy default theme into new site
 	copyTheme(defaultTheme, path)
+
 	return nil
 }
 
diff --git a/manifest.go b/manifest.go
new file mode 100644
index 0000000..8e0f249
--- /dev/null
+++ b/manifest.go
@@ -0,0 +1,57 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+
+	"go.imnhan.com/webmaker2000/writablefs"
+)
+
+const ManifestPath = "manifest.txt"
+
+// Write list of files generated by webmaker2000
+func WriteManifest(fsys writablefs.FS, files map[string]bool) {
+	content := ""
+
+	for path := range files {
+		content += path + "\n"
+	}
+
+	fsys.WriteFile(ManifestPath, []byte(content))
+}
+
+// Read list of old generated files from the manifest file,
+// then delete those that are no longer relevant.
+func DeleteOldGeneratedFiles(fsys writablefs.FS, currentFiles map[string]bool) {
+	oldFiles := readManifest(fsys)
+	numRemovals := 0
+
+	for path := range oldFiles {
+		_, ok := currentFiles[path]
+		if !ok {
+			fsys.RemoveAll(path)
+			numRemovals += 1
+			fmt.Println("Removed", path)
+		}
+	}
+
+	if numRemovals > 0 {
+		fmt.Printf("Removed %d outdated files\n", numRemovals)
+	}
+}
+
+func readManifest(fsys writablefs.FS) map[string]bool {
+	result := make(map[string]bool)
+
+	f, err := fsys.Open(ManifestPath)
+	if err != nil {
+		return result
+	}
+	defer f.Close()
+
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		result[s.Text()] = true
+	}
+	return result
+}
diff --git a/watcher.go b/watcher.go
index 0e2baf8..d24f350 100644
--- a/watcher.go
+++ b/watcher.go
@@ -111,5 +111,7 @@ func printWatchList(w *fsnotify.Watcher) {
 // temp files or supporting data like .git.
 func shouldIgnore(path string) bool {
 	fname := filepath.Base(path)
-	return fname[0] == '.' || strings.HasSuffix(fname, ".swp")
+	return fname[0] == '.' ||
+		fname == ManifestPath ||
+		strings.HasSuffix(fname, ".swp")
 }
diff --git a/www/manifest.txt b/www/manifest.txt
new file mode 100644
index 0000000..c86a93d
--- /dev/null
+++ b/www/manifest.txt
@@ -0,0 +1,5 @@
+mfws.html
+hello/index.html
+about/index.html
+index.html
+feed.xml