improve readability

file_tree.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"os"
 	"path"
 	"path/filepath"
@@ -30,22 +31,24 @@ type File struct {
 func parsePage(fullpath string) (hugo.Page, error) {
 	file, err := os.Open(fullpath)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("file open: %w", err)
 	}
 	defer file.Close()
 
 	page, err := hugo.ReadFrom(file)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("hugo read from: %w", err)
 	}
+
 	return page, nil
 }
 
 func parseMetadata(page hugo.Page) (*hugo.PageMetadata, error) {
 	meta, err := page.Metadata()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("page metadata: %w", err)
 	}
+
 	c := NewContentFromMeta(meta)
 
 	return c, nil
@@ -54,18 +57,23 @@ func parseMetadata(page hugo.Page) (*hugo.PageMetadata, error) {
 func destinationPath(file *File, pattern string) error {
 	p, err := parsePage(file.Source)
 	if err != nil {
-		return err
+		return fmt.Errorf("parse page: %w", err)
 	}
 
 	// create content
 	c, err := parseMetadata(p)
+	if err != nil {
+		return fmt.Errorf("parse metadata: %w", err)
+	}
+
 	c.Filepath = file.Name
 
 	if file.Parent != "." {
 		link, err := hugo.PathPattern(pattern).Expand(c)
 		if err != nil {
-			return err
+			return fmt.Errorf("hugo pathpattern: %w", err)
 		}
+
 		file.Destination = link
 	} else {
 		file.Destination = strings.TrimLeft(file.Name, "_")
@@ -80,7 +88,8 @@ func destinationPath(file *File, pattern string) error {
 
 func collectFiles(fullpath string, filechan chan File) error {
 	defer close(filechan)
-	return filepath.Walk(fullpath,
+
+	err := filepath.Walk(fullpath,
 		func(p string, info os.FileInfo, err error) error {
 			if err != nil {
 				return err
@@ -91,7 +100,7 @@ func collectFiles(fullpath string, filechan chan File) error {
 
 			rel, err := filepath.Rel(fullpath, p)
 			if err != nil {
-				return err
+				return fmt.Errorf("rel path: %w", err)
 			}
 
 			filename := info.Name()
@@ -109,4 +118,9 @@ func collectFiles(fullpath string, filechan chan File) error {
 
 			return nil
 		})
+	if err != nil {
+		return fmt.Errorf("filetree walk: %w", err)
+	}
+
+	return nil
 }

main.go

@@ -4,10 +4,8 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
-	"io"
 	"log"
 	"os"
-	"os/exec"
 	"path/filepath"
 
 	"github.com/gohugoio/hugo/config"
@@ -67,6 +65,7 @@ func main() {
 		if ok {
 			return format
 		}
+
 		return defaultPermalinkFormat
 	}
 
@@ -78,8 +77,10 @@ func main() {
 
 	// for each file, get destination path, switch file extension, remove underscore for index
 	var tree FileTree
+
 	for file := range files {
 		pattern := linkpattern(file.Parent)
+
 		err := destinationPath(&file, pattern)
 		if err != nil {
 			log.Fatalf("failed to derive destination for %v error: %v", file.Source, err)
@@ -87,15 +88,21 @@ func main() {
 
 		if file.Draft && !buildDrafts {
 			fmt.Printf("skipping draft %s (%dbytes)\n", file.Source, len(file.Body))
+
 			continue
 		}
+
 		tree.Files = append(tree.Files, file)
 	}
 
 	// call proc and pipe content through it, catch output of proc
 	for i, file := range tree.Files {
 		buf := bytes.NewReader(file.Body)
-		out := pipe(pipecmd, buf)
+
+		out, err := pipe(pipecmd, buf)
+		if err != nil {
+			log.Fatalf("pipe command '%v' failed with %v", pipecmd, err)
+		}
 
 		// write to source
 		tree.Files[i].NewBody = out
@@ -133,8 +140,8 @@ func main() {
 		if err != nil {
 			log.Fatalf("cannot write file %s, error: %v", fullpath, err)
 		}
-		newfile.Close()
 
+		newfile.Close()
 		fmt.Printf("written %s (%dbytes)\n", fullpath, n)
 	}
 
@@ -145,21 +152,21 @@ func main() {
 
 	// aggregate sections and section entries
 	sections := make(map[string]*Section)
+
 	for _, file := range tree.Files {
 		// not a section
 		if file.Parent == "." {
 			continue
 		}
+
 		name := file.Parent
 		sectionFile := filepath.Join(destination, file.Parent, "index."+ext)
 
-		//fmt.Printf("section %v\n", sectionFile)
 		link := file.Destination
 		if uglyURLs {
 			link += "." + ext
 		}
 
-		//fmt.Printf("link %v\n", link)
 		if _, ok := sections[name]; !ok {
 			sections[name] = &Section{File: sectionFile}
 		}
@@ -175,57 +182,24 @@ func main() {
 	for name, section := range sections {
 		// TODO: come up with sth better as one might have content there.
 		os.Remove(section.File)
-		section.Write(section.File)
+
+		err := section.Write(section.File)
+		if err != nil {
+			log.Fatalf("cannot write file %s, error: %v", section.File, err)
+		}
+
 		fmt.Printf("written section listing %s to %s\n", name, section.File)
 	}
 
 	section, ok := sections[seconOnRoot]
 	if ok {
 		sectionFile := filepath.Join(destination, "index."+ext)
-		section.Write(sectionFile)
+
+		err := section.Write(sectionFile)
+		if err != nil {
+			log.Fatalf("cannot append to file %s, error: %v", sectionFile, err)
+		}
+
 		fmt.Printf("written section listing for root to %s\n", section.File)
 	}
 }
-
-func pipe(cmd string, input io.Reader) []byte {
-	extpipe := exec.Command(cmd)
-	extpipe.Stdin = input
-
-	var pipeout bytes.Buffer
-	extpipe.Stdout = &pipeout
-
-	extpipe.Start()
-	extpipe.Wait()
-
-	return pipeout.Bytes()
-}
-
-func targetPath(dest, newext string, uglyURLs bool) (dir string, filename string) {
-	filename = "index." + newext
-	dir = dest
-
-	if uglyURLs && dest != "index" {
-		// make the last element in destination the file
-		filename = filepath.Base(dest) + "." + newext
-		// set the parent directory of that file to be the dir to create
-		dir = filepath.Dir(dest)
-	}
-
-	if dest == "index" {
-		dir = "."
-	}
-	return
-}
-
-func mkdir(dir string) (bool, error) {
-	// skip if this exists
-	if _, err := os.Stat(dir); err == nil {
-		return false, nil
-	}
-
-	if err := os.MkdirAll(dir, os.ModePerm); err != nil {
-		return false, err
-	}
-
-	return true, nil
-}

page_metadata.go

@@ -32,8 +32,8 @@ func dateFromInterface(input interface{}) time.Time {
 	str, ok := input.(string)
 	if !ok {
 		return time.Now()
-
 	}
+
 	t, err := time.Parse(time.RFC3339, str)
 	if err != nil {
 		// try just date, or give up
@@ -41,8 +41,10 @@ func dateFromInterface(input interface{}) time.Time {
 		if err != nil {
 			return time.Now()
 		}
+
 		return t
 	}
+
 	return t
 }
 
@@ -53,7 +55,9 @@ func stringArrayFromInterface(input interface{}) []string {
 		for _, str := range strarr {
 			out = append(out, stringFromInterface(str))
 		}
+
 		return out
 	}
+
 	return nil
 }

pipe.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+func pipe(cmd string, input io.Reader) ([]byte, error) {
+	extpipe := exec.Command(cmd)
+	extpipe.Stdin = input
+
+	var pipeout bytes.Buffer
+	extpipe.Stdout = &pipeout
+
+	if err := extpipe.Start(); err != nil {
+		return nil, fmt.Errorf("pipe start: %w", err)
+	}
+
+	if err := extpipe.Wait(); err != nil {
+		return nil, fmt.Errorf("pipe wait: %w", err)
+	}
+
+	return pipeout.Bytes(), nil
+}
+
+func targetPath(dest, newext string, uglyURLs bool) (dir string, filename string) {
+	filename = "index." + newext
+	dir = dest
+
+	if uglyURLs && dest != "index" {
+		// make the last element in destination the file
+		filename = filepath.Base(dest) + "." + newext
+		// set the parent directory of that file to be the dir to create
+		dir = filepath.Dir(dest)
+	}
+
+	if dest == "index" {
+		dir = "."
+	}
+
+	return
+}
+
+func mkdir(dir string) (bool, error) {
+	// skip if this exists
+	if _, err := os.Stat(dir); err == nil {
+		return false, nil
+	}
+
+	if err := os.MkdirAll(dir, os.ModePerm); err != nil {
+		return false, fmt.Errorf("mkdir: %w", err)
+	}
+
+	return true, nil
+}

section_list.go

@@ -27,6 +27,7 @@ func (section *Section) Write(file string) error {
 	})
 
 	var buf bytes.Buffer
+
 	for _, file := range section.List {
 		// TODO: this could be a template
 		entry := "\n"
@@ -38,9 +39,11 @@ func (section *Section) Write(file string) error {
 
 	f, err := os.OpenFile(file, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
 	if err != nil {
-		return err
+		return fmt.Errorf("open file: %w", err)
 	}
+
 	_, err = f.Write(buf.Bytes())
 	f.Close()
+
 	return err
 }