From e7db83bc9685538d0511087b298549fac26ede41 Mon Sep 17 00:00:00 2001
From: Snider <snider@lt.hn>
Date: Mon, 3 Nov 2025 03:42:21 +0000
Subject: [PATCH] Add initialization comments for command registration in CLI

---
 cmd/all.go                               |  1 +
 cmd/collect.go                           |  1 +
 cmd/collect_github.go                    |  1 +
 cmd/collect_github_release_subcommand.go |  1 +
 cmd/collect_github_repo.go               |  1 +
 cmd/collect_github_repos.go              |  1 +
 cmd/collect_pwa.go                       |  1 +
 cmd/collect_website.go                   |  3 +-
 cmd/root.go                              |  1 +
 cmd/serve.go                             |  1 +
 main.go                                  |  1 +
 pkg/datanode/datanode.go                 | 59 +++++++++++++++++++-----
 pkg/github/github.go                     |  5 ++
 pkg/logger/logger.go                     |  2 +
 pkg/pwa/pwa.go                           |  2 +
 pkg/tarfs/tarfs.go                       | 30 +++++++++---
 pkg/ui/non_interactive_prompter.go       |  7 +++
 pkg/ui/progress_writer.go                |  5 +-
 pkg/ui/quote.go                          |  8 ++++
 pkg/website/website.go                   |  7 +++
 20 files changed, 119 insertions(+), 19 deletions(-)

diff --git a/cmd/all.go b/cmd/all.go
index 7f7c782..c7075f0 100644
--- a/cmd/all.go
+++ b/cmd/all.go
@@ -60,6 +60,7 @@ var allCmd = &cobra.Command{
 	},
 }
 
+// init registers the 'all' command and its flags with the root command.
 func init() {
 	RootCmd.AddCommand(allCmd)
 	allCmd.PersistentFlags().String("output", ".", "Output directory for the DataNodes")
diff --git a/cmd/collect.go b/cmd/collect.go
index 8e3d817..eaec82f 100644
--- a/cmd/collect.go
+++ b/cmd/collect.go
@@ -11,6 +11,7 @@ var collectCmd = &cobra.Command{
 	Long:  `Collect a resource from a git repository, a website, or other URI and store it in a DataNode.`,
 }
 
+// init registers the collect command with the root.
 func init() {
 	RootCmd.AddCommand(collectCmd)
 }
diff --git a/cmd/collect_github.go b/cmd/collect_github.go
index 58d6f8d..f44e386 100644
--- a/cmd/collect_github.go
+++ b/cmd/collect_github.go
@@ -11,6 +11,7 @@ var collectGithubCmd = &cobra.Command{
 	Long:  `Collect a resource from a GitHub repository, such as a repository or a release.`,
 }
 
+// init registers the GitHub collection parent command.
 func init() {
 	collectCmd.AddCommand(collectGithubCmd)
 }
diff --git a/cmd/collect_github_release_subcommand.go b/cmd/collect_github_release_subcommand.go
index 83565c0..05f4ac5 100644
--- a/cmd/collect_github_release_subcommand.go
+++ b/cmd/collect_github_release_subcommand.go
@@ -126,6 +126,7 @@ var collectGithubReleaseCmd = &cobra.Command{
 	},
 }
 
+// init registers the 'collect github release' subcommand and its flags.
 func init() {
 	collectGithubCmd.AddCommand(collectGithubReleaseCmd)
 	collectGithubReleaseCmd.PersistentFlags().String("output", ".", "Output directory for the downloaded file")
diff --git a/cmd/collect_github_repo.go b/cmd/collect_github_repo.go
index f279129..97b0f1c 100644
--- a/cmd/collect_github_repo.go
+++ b/cmd/collect_github_repo.go
@@ -89,6 +89,7 @@ var collectGithubRepoCmd = &cobra.Command{
 	},
 }
 
+// init registers the 'collect github repo' subcommand and its flags.
 func init() {
 	collectGithubCmd.AddCommand(collectGithubRepoCmd)
 	collectGithubRepoCmd.PersistentFlags().String("output", "", "Output file for the DataNode")
diff --git a/cmd/collect_github_repos.go b/cmd/collect_github_repos.go
index dfcd315..e495a27 100644
--- a/cmd/collect_github_repos.go
+++ b/cmd/collect_github_repos.go
@@ -28,6 +28,7 @@ var collectGithubReposCmd = &cobra.Command{
 	},
 }
 
+// init registers the 'collect github repos' subcommand.
 func init() {
 	collectGithubCmd.AddCommand(collectGithubReposCmd)
 }
diff --git a/cmd/collect_pwa.go b/cmd/collect_pwa.go
index 06e06f5..d1ce59d 100644
--- a/cmd/collect_pwa.go
+++ b/cmd/collect_pwa.go
@@ -94,6 +94,7 @@ Example:
 	},
 }
 
+// init registers the 'collect pwa' subcommand and its flags.
 func init() {
 	collectCmd.AddCommand(collectPWACmd)
 	collectPWACmd.Flags().String("uri", "", "The URI of the PWA to collect")
diff --git a/cmd/collect_website.go b/cmd/collect_website.go
index 6b67a3b..97ed59e 100644
--- a/cmd/collect_website.go
+++ b/cmd/collect_website.go
@@ -4,11 +4,11 @@ import (
 	"fmt"
 	"os"
 
-	"github.com/schollz/progressbar/v3"
 	"github.com/Snider/Borg/pkg/compress"
 	"github.com/Snider/Borg/pkg/matrix"
 	"github.com/Snider/Borg/pkg/ui"
 	"github.com/Snider/Borg/pkg/website"
+	"github.com/schollz/progressbar/v3"
 
 	"github.com/spf13/cobra"
 )
@@ -83,6 +83,7 @@ var collectWebsiteCmd = &cobra.Command{
 	},
 }
 
+// init registers the 'collect website' subcommand and its flags.
 func init() {
 	collectCmd.AddCommand(collectWebsiteCmd)
 	collectWebsiteCmd.PersistentFlags().String("output", "", "Output file for the DataNode")
diff --git a/cmd/root.go b/cmd/root.go
index 9cadb27..651f2f7 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -7,6 +7,7 @@ import (
 	"github.com/spf13/cobra"
 )
 
+// NewRootCmd constructs the root cobra.Command for the Borg CLI and wires common flags.
 func NewRootCmd() *cobra.Command {
 	rootCmd := &cobra.Command{
 		Use:   "borg",
diff --git a/cmd/serve.go b/cmd/serve.go
index 87e225f..15d333d 100644
--- a/cmd/serve.go
+++ b/cmd/serve.go
@@ -62,6 +62,7 @@ var serveCmd = &cobra.Command{
 	},
 }
 
+// init registers the 'serve' command and its flags with the root command.
 func init() {
 	RootCmd.AddCommand(serveCmd)
 	serveCmd.PersistentFlags().String("port", "8080", "Port to serve the PWA on")
diff --git a/main.go b/main.go
index 7c02e17..4064295 100644
--- a/main.go
+++ b/main.go
@@ -7,6 +7,7 @@ import (
 	"github.com/Snider/Borg/pkg/logger"
 )
 
+// main is the entry point for the Borg CLI application.
 func main() {
 	verbose, _ := cmd.RootCmd.PersistentFlags().GetBool("verbose")
 	log := logger.New(verbose)
diff --git a/pkg/datanode/datanode.go b/pkg/datanode/datanode.go
index fe2f43b..881ac8c 100644
--- a/pkg/datanode/datanode.go
+++ b/pkg/datanode/datanode.go
@@ -260,19 +260,35 @@ type dataFile struct {
 	modTime time.Time
 }
 
+// Stat implements fs.File.Stat for a dataFile and returns its FileInfo.
 func (d *dataFile) Stat() (fs.FileInfo, error) { return &dataFileInfo{file: d}, nil }
+
+// Read implements fs.File.Read for a dataFile and reports EOF as files are in-memory.
 func (d *dataFile) Read(p []byte) (int, error) { return 0, io.EOF }
-func (d *dataFile) Close() error               { return nil }
+
+// Close implements fs.File.Close for a dataFile; it's a no-op.
+func (d *dataFile) Close() error { return nil }
 
 // dataFileInfo implements fs.FileInfo for a dataFile.
 type dataFileInfo struct{ file *dataFile }
 
-func (d *dataFileInfo) Name() string       { return path.Base(d.file.name) }
-func (d *dataFileInfo) Size() int64        { return int64(len(d.file.content)) }
-func (d *dataFileInfo) Mode() fs.FileMode  { return 0444 }
+// Name returns the base name of the data file.
+func (d *dataFileInfo) Name() string { return path.Base(d.file.name) }
+
+// Size returns the size of the data file in bytes.
+func (d *dataFileInfo) Size() int64 { return int64(len(d.file.content)) }
+
+// Mode returns the file mode for data files (read-only).
+func (d *dataFileInfo) Mode() fs.FileMode { return 0444 }
+
+// ModTime returns the modification time of the data file.
 func (d *dataFileInfo) ModTime() time.Time { return d.file.modTime }
-func (d *dataFileInfo) IsDir() bool        { return false }
-func (d *dataFileInfo) Sys() interface{}   { return nil }
+
+// IsDir reports whether the entry is a directory (false for data files).
+func (d *dataFileInfo) IsDir() bool { return false }
+
+// Sys returns system-specific data, which is nil for data files.
+func (d *dataFileInfo) Sys() interface{} { return nil }
 
 // dataFileReader implements fs.File for a dataFile.
 type dataFileReader struct {
@@ -280,13 +296,18 @@ type dataFileReader struct {
 	reader *bytes.Reader
 }
 
+// Stat returns the FileInfo for the underlying data file.
 func (d *dataFileReader) Stat() (fs.FileInfo, error) { return d.file.Stat() }
+
+// Read reads from the underlying data file content.
 func (d *dataFileReader) Read(p []byte) (int, error) {
 	if d.reader == nil {
 		d.reader = bytes.NewReader(d.file.content)
 	}
 	return d.reader.Read(p)
 }
+
+// Close closes the data file reader (no-op).
 func (d *dataFileReader) Close() error { return nil }
 
 // dirInfo implements fs.FileInfo for an implicit directory.
@@ -295,12 +316,23 @@ type dirInfo struct {
 	modTime time.Time
 }
 
-func (d *dirInfo) Name() string       { return d.name }
-func (d *dirInfo) Size() int64        { return 0 }
-func (d *dirInfo) Mode() fs.FileMode  { return fs.ModeDir | 0555 }
+// Name returns the directory name.
+func (d *dirInfo) Name() string { return d.name }
+
+// Size returns the size of the directory entry (always 0 for virtual dirs).
+func (d *dirInfo) Size() int64 { return 0 }
+
+// Mode returns the file mode for directories.
+func (d *dirInfo) Mode() fs.FileMode { return fs.ModeDir | 0555 }
+
+// ModTime returns the modification time of the directory.
 func (d *dirInfo) ModTime() time.Time { return d.modTime }
-func (d *dirInfo) IsDir() bool        { return true }
-func (d *dirInfo) Sys() interface{}   { return nil }
+
+// IsDir reports that the entry is a directory.
+func (d *dirInfo) IsDir() bool { return true }
+
+// Sys returns system-specific data, which is nil for dirs.
+func (d *dirInfo) Sys() interface{} { return nil }
 
 // dirFile implements fs.File for a directory.
 type dirFile struct {
@@ -308,10 +340,15 @@ type dirFile struct {
 	modTime time.Time
 }
 
+// Stat returns the FileInfo for the directory.
 func (d *dirFile) Stat() (fs.FileInfo, error) {
 	return &dirInfo{name: path.Base(d.path), modTime: d.modTime}, nil
 }
+
+// Read is invalid for directories and returns an error.
 func (d *dirFile) Read([]byte) (int, error) {
 	return 0, &fs.PathError{Op: "read", Path: d.path, Err: fs.ErrInvalid}
 }
+
+// Close closes the directory file (no-op).
 func (d *dirFile) Close() error { return nil }
diff --git a/pkg/github/github.go b/pkg/github/github.go
index 022e255..1eed699 100644
--- a/pkg/github/github.go
+++ b/pkg/github/github.go
@@ -31,6 +31,8 @@ func (g *githubClient) GetPublicRepos(ctx context.Context, userOrOrg string) ([]
 	return g.getPublicReposWithAPIURL(ctx, "https://api.github.com", userOrOrg)
 }
 
+// newAuthenticatedClient returns an *http.Client that uses GITHUB_TOKEN if set.
+// When no token is present, it falls back to http.DefaultClient.
 func (g *githubClient) newAuthenticatedClient(ctx context.Context) *http.Client {
 	token := os.Getenv("GITHUB_TOKEN")
 	if token == "" {
@@ -42,6 +44,8 @@ func (g *githubClient) newAuthenticatedClient(ctx context.Context) *http.Client
 	return oauth2.NewClient(ctx, ts)
 }
 
+// getPublicReposWithAPIURL fetches public repository clone URLs for the given user/org
+// using the provided GitHub API base URL, following pagination links as needed.
 func (g *githubClient) getPublicReposWithAPIURL(ctx context.Context, apiURL, userOrOrg string) ([]string, error) {
 	client := g.newAuthenticatedClient(ctx)
 	var allCloneURLs []string
@@ -106,6 +110,7 @@ func (g *githubClient) getPublicReposWithAPIURL(ctx context.Context, apiURL, use
 	return allCloneURLs, nil
 }
 
+// findNextURL parses the HTTP Link header and returns the URL with rel="next", if any.
 func (g *githubClient) findNextURL(linkHeader string) string {
 	links := strings.Split(linkHeader, ",")
 	for _, link := range links {
diff --git a/pkg/logger/logger.go b/pkg/logger/logger.go
index 0dfc2d2..5984095 100644
--- a/pkg/logger/logger.go
+++ b/pkg/logger/logger.go
@@ -5,6 +5,8 @@ import (
 	"os"
 )
 
+// New constructs a slog.Logger configured for stderr with the given verbosity.
+// When verbose is true, the logger emits debug-level messages; otherwise info-level.
 func New(verbose bool) *slog.Logger {
 	level := slog.LevelInfo
 	if verbose {
diff --git a/pkg/pwa/pwa.go b/pkg/pwa/pwa.go
index 0d72345..0885811 100644
--- a/pkg/pwa/pwa.go
+++ b/pkg/pwa/pwa.go
@@ -158,6 +158,7 @@ func (p *pwaClient) DownloadAndPackagePWA(baseURL string, manifestURL string, ba
 	return dn, nil
 }
 
+// resolveURL resolves ref against base and returns the absolute URL.
 func (p *pwaClient) resolveURL(base, ref string) (*url.URL, error) {
 	baseURL, err := url.Parse(base)
 	if err != nil {
@@ -170,6 +171,7 @@ func (p *pwaClient) resolveURL(base, ref string) (*url.URL, error) {
 	return baseURL.ResolveReference(refURL), nil
 }
 
+// downloadAndAddFile downloads fileURL and adds it to dn at internalPath, updating the progress bar.
 func (p *pwaClient) downloadAndAddFile(dn *datanode.DataNode, fileURL *url.URL, internalPath string, bar *progressbar.ProgressBar) error {
 	resp, err := p.client.Get(fileURL.String())
 	if err != nil {
diff --git a/pkg/tarfs/tarfs.go b/pkg/tarfs/tarfs.go
index 6abbee4..c60ef9c 100644
--- a/pkg/tarfs/tarfs.go
+++ b/pkg/tarfs/tarfs.go
@@ -67,16 +67,23 @@ type tarFile struct {
 	modTime time.Time
 }
 
-func (f *tarFile) Close() error               { return nil }
+// Close implements http.File Close with a no-op for tar-backed files.
+func (f *tarFile) Close() error { return nil }
+
+// Read implements io.Reader by delegating to the underlying bytes.Reader.
 func (f *tarFile) Read(p []byte) (int, error) { return f.content.Read(p) }
+
+// Seek implements io.Seeker by delegating to the underlying bytes.Reader.
 func (f *tarFile) Seek(offset int64, whence int) (int64, error) {
 	return f.content.Seek(offset, whence)
 }
 
+// Readdir is unsupported for files in the tar filesystem and returns os.ErrInvalid.
 func (f *tarFile) Readdir(count int) ([]os.FileInfo, error) {
 	return nil, os.ErrInvalid
 }
 
+// Stat returns a FileInfo describing the tar-backed file.
 func (f *tarFile) Stat() (os.FileInfo, error) {
 	return &tarFileInfo{
 		name:    path.Base(f.header.Name),
@@ -92,9 +99,20 @@ type tarFileInfo struct {
 	modTime time.Time
 }
 
-func (i *tarFileInfo) Name() string       { return i.name }
-func (i *tarFileInfo) Size() int64        { return i.size }
-func (i *tarFileInfo) Mode() os.FileMode  { return 0444 }
+// Name returns the base name of the tar file.
+func (i *tarFileInfo) Name() string { return i.name }
+
+// Size returns the size of the tar file in bytes.
+func (i *tarFileInfo) Size() int64 { return i.size }
+
+// Mode returns a read-only file mode for tar entries.
+func (i *tarFileInfo) Mode() os.FileMode { return 0444 }
+
+// ModTime returns the modification time recorded in the tar header.
 func (i *tarFileInfo) ModTime() time.Time { return i.modTime }
-func (i *tarFileInfo) IsDir() bool        { return false }
-func (i *tarFileInfo) Sys() interface{}   { return nil }
+
+// IsDir reports whether the entry is a directory (always false for files here).
+func (i *tarFileInfo) IsDir() bool { return false }
+
+// Sys returns underlying data source (unused for tar entries).
+func (i *tarFileInfo) Sys() interface{} { return nil }
diff --git a/pkg/ui/non_interactive_prompter.go b/pkg/ui/non_interactive_prompter.go
index 8144a72..35d99d5 100644
--- a/pkg/ui/non_interactive_prompter.go
+++ b/pkg/ui/non_interactive_prompter.go
@@ -10,6 +10,8 @@ import (
 	"github.com/mattn/go-isatty"
 )
 
+// NonInteractivePrompter periodically prints status quotes when the terminal is non-interactive.
+// It is intended to give the user feedback during long-running operations.
 type NonInteractivePrompter struct {
 	stopChan  chan struct{}
 	quoteFunc func() (string, error)
@@ -18,6 +20,8 @@ type NonInteractivePrompter struct {
 	stopOnce  sync.Once
 }
 
+// NewNonInteractivePrompter returns a new NonInteractivePrompter that will call
+// the provided quoteFunc to retrieve text to display.
 func NewNonInteractivePrompter(quoteFunc func() (string, error)) *NonInteractivePrompter {
 	return &NonInteractivePrompter{
 		stopChan:  make(chan struct{}),
@@ -25,6 +29,7 @@ func NewNonInteractivePrompter(quoteFunc func() (string, error)) *NonInteractive
 	}
 }
 
+// Start begins the periodic display of quotes until Stop is called.
 func (p *NonInteractivePrompter) Start() {
 	p.mu.Lock()
 	if p.started {
@@ -59,6 +64,7 @@ func (p *NonInteractivePrompter) Start() {
 	}()
 }
 
+// Stop signals the prompter to stop printing further messages.
 func (p *NonInteractivePrompter) Stop() {
 	if p.IsInteractive() {
 		return
@@ -68,6 +74,7 @@ func (p *NonInteractivePrompter) Stop() {
 	})
 }
 
+// IsInteractive reports whether stdout is attached to an interactive terminal.
 func (p *NonInteractivePrompter) IsInteractive() bool {
 	return isatty.IsTerminal(os.Stdout.Fd()) || isatty.IsCygwinTerminal(os.Stdout.Fd())
 }
diff --git a/pkg/ui/progress_writer.go b/pkg/ui/progress_writer.go
index b46b51b..510d169 100644
--- a/pkg/ui/progress_writer.go
+++ b/pkg/ui/progress_writer.go
@@ -1,16 +1,19 @@
-
 package ui
 
 import "github.com/schollz/progressbar/v3"
 
+// progressWriter implements io.Writer to update a progress bar with textual status.
 type progressWriter struct {
 	bar *progressbar.ProgressBar
 }
 
+// NewProgressWriter returns a writer that updates the provided progress bar's description.
 func NewProgressWriter(bar *progressbar.ProgressBar) *progressWriter {
 	return &progressWriter{bar: bar}
 }
 
+// Write updates the progress bar description with the provided bytes as a string.
+// It returns the length of p to satisfy io.Writer semantics.
 func (pw *progressWriter) Write(p []byte) (n int, err error) {
 	if pw == nil || pw.bar == nil {
 		return len(p), nil
diff --git a/pkg/ui/quote.go b/pkg/ui/quote.go
index 166cf91..9e72716 100644
--- a/pkg/ui/quote.go
+++ b/pkg/ui/quote.go
@@ -16,6 +16,7 @@ var (
 	quotesErr    error
 )
 
+// init seeds the random number generator for quote selection.
 func init() {
 	rand.Seed(time.Now().UnixNano())
 }
@@ -41,6 +42,7 @@ type Quotes struct {
 	} `json:"image_related"`
 }
 
+// loadQuotes reads and unmarshals the embedded quotes.json file into a Quotes struct.
 func loadQuotes() (*Quotes, error) {
 	quotesFile, err := QuotesJSON.ReadFile("quotes.json")
 	if err != nil {
@@ -54,6 +56,7 @@ func loadQuotes() (*Quotes, error) {
 	return &quotes, nil
 }
 
+// getQuotes returns the cached Quotes, loading them once on first use.
 func getQuotes() (*Quotes, error) {
 	quotesOnce.Do(func() {
 		cachedQuotes, quotesErr = loadQuotes()
@@ -61,6 +64,7 @@ func getQuotes() (*Quotes, error) {
 	return cachedQuotes, quotesErr
 }
 
+// GetRandomQuote returns a random quote string from the combined quote sets.
 func GetRandomQuote() (string, error) {
 	quotes, err := getQuotes()
 	if err != nil {
@@ -82,6 +86,7 @@ func GetRandomQuote() (string, error) {
 	return allQuotes[rand.Intn(len(allQuotes))], nil
 }
 
+// PrintQuote prints a random quote to stdout in green for user feedback.
 func PrintQuote() {
 	quote, err := GetRandomQuote()
 	if err != nil {
@@ -92,6 +97,7 @@ func PrintQuote() {
 	c.Println(quote)
 }
 
+// GetVCSQuote returns a random quote related to VCS processing.
 func GetVCSQuote() (string, error) {
 	quotes, err := getQuotes()
 	if err != nil {
@@ -103,6 +109,7 @@ func GetVCSQuote() (string, error) {
 	return quotes.VCSProcessing[rand.Intn(len(quotes.VCSProcessing))], nil
 }
 
+// GetPWAQuote returns a random quote related to PWA processing.
 func GetPWAQuote() (string, error) {
 	quotes, err := getQuotes()
 	if err != nil {
@@ -114,6 +121,7 @@ func GetPWAQuote() (string, error) {
 	return quotes.PWAProcessing[rand.Intn(len(quotes.PWAProcessing))], nil
 }
 
+// GetWebsiteQuote returns a random quote related to website processing.
 func GetWebsiteQuote() (string, error) {
 	quotes, err := getQuotes()
 	if err != nil {
diff --git a/pkg/website/website.go b/pkg/website/website.go
index 1780c0e..5a3d37c 100644
--- a/pkg/website/website.go
+++ b/pkg/website/website.go
@@ -53,6 +53,8 @@ func DownloadAndPackageWebsite(startURL string, maxDepth int, bar *progressbar.P
 	return d.dn, nil
 }
 
+// crawl traverses the website starting from pageURL up to maxDepth,
+// storing pages and discovered local assets into the DataNode.
 func (d *Downloader) crawl(pageURL string, depth int) {
 	if depth > d.maxDepth || d.visited[pageURL] {
 		return
@@ -110,6 +112,7 @@ func (d *Downloader) crawl(pageURL string, depth int) {
 	f(doc)
 }
 
+// downloadAsset fetches a single asset URL and stores it into the DataNode.
 func (d *Downloader) downloadAsset(assetURL string) {
 	if d.visited[assetURL] {
 		return
@@ -136,6 +139,7 @@ func (d *Downloader) downloadAsset(assetURL string) {
 	d.dn.AddData(relPath, body)
 }
 
+// getRelativePath returns a path relative to the site's root for the given URL.
 func (d *Downloader) getRelativePath(pageURL string) string {
 	u, err := url.Parse(pageURL)
 	if err != nil {
@@ -144,6 +148,7 @@ func (d *Downloader) getRelativePath(pageURL string) string {
 	return strings.TrimPrefix(u.Path, "/")
 }
 
+// resolveURL resolves ref against base and returns the absolute URL string.
 func (d *Downloader) resolveURL(base, ref string) (string, error) {
 	baseURL, err := url.Parse(base)
 	if err != nil {
@@ -156,6 +161,7 @@ func (d *Downloader) resolveURL(base, ref string) (string, error) {
 	return baseURL.ResolveReference(refURL).String(), nil
 }
 
+// isLocal reports whether pageURL belongs to the same host as the base URL.
 func (d *Downloader) isLocal(pageURL string) bool {
 	u, err := url.Parse(pageURL)
 	if err != nil {
@@ -164,6 +170,7 @@ func (d *Downloader) isLocal(pageURL string) bool {
 	return u.Hostname() == d.baseURL.Hostname()
 }
 
+// isAsset reports whether the URL likely points to a static asset we should download.
 func isAsset(pageURL string) bool {
 	ext := []string{".css", ".js", ".png", ".jpg", ".jpeg", ".gif", ".svg", ".ico"}
 	for _, e := range ext {