better error handling and fix lack of string trim

.travis.yml

@@ -0,0 +1,11 @@
+language: go
+go:
+  - 1.10.x
+  - master
+sudo: false
+
+install: true
+
+script:
+  - env GO111MODULE=on go build
+  - env GO111MODULE=on go test

go.mod

@@ -0,0 +1,9 @@
+module github.com/dvdscripter/elvuiUpdater
+
+require (
+	github.com/PuerkitoBio/goquery v1.4.1
+	github.com/andybalholm/cascadia v1.0.0 // indirect
+	github.com/pkg/errors v0.8.0
+	golang.org/x/net v0.0.0-20181003013248-f5e5bdd77824 // indirect
+	golang.org/x/sys v0.0.0-20181003145944-af653ce8b74f
+)

go.sum

@@ -0,0 +1,11 @@
+github.com/PuerkitoBio/goquery v1.4.1 h1:smcIRGdYm/w7JSbcdeLHEMzxmsBQvl8lhf0dSw2nzMI=
+github.com/PuerkitoBio/goquery v1.4.1/go.mod h1:T9ezsOHcCrDCgA8aF1Cqr3sSYbO/xgdy8/R/XiIMAhA=
+github.com/andybalholm/cascadia v1.0.0 h1:hOCXnnZ5A+3eVDX8pvgl4kofXv2ELss0bKcqRySc45o=
+github.com/andybalholm/cascadia v1.0.0/go.mod h1:GsXiBklL0woXo1j/WYWtSYYC4ouU9PqHO0sqidkEA4Y=
+github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw=
+github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+golang.org/x/net v0.0.0-20180218175443-cbe0f9307d01/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20181003013248-f5e5bdd77824 h1:MkjFNbaZJyH98M67Q3umtwZ+EdVdrNJLqSwZp5vcv60=
+golang.org/x/net v0.0.0-20181003013248-f5e5bdd77824/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sys v0.0.0-20181003145944-af653ce8b74f h1:zAtpFwFDtnvBWPPelq8CSiqRN1wrIzMUk9dwzbpjpNM=
+golang.org/x/sys v0.0.0-20181003145944-af653ce8b74f/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=

main.go

@@ -18,6 +18,7 @@ import (
 	"golang.org/x/sys/windows/registry"
 
 	"github.com/PuerkitoBio/goquery"
+	"github.com/pkg/errors"
 )
 
 type configuration struct {
@@ -37,21 +38,21 @@ type elvui struct {
 func (e *elvui) init(configPath string) error {
 	rawConfig, err := ioutil.ReadFile(configPath)
 	if err != nil {
-		return err
+		return errors.Wrapf(err, "cannot read file %s", configPath)
 	}
 	if err = json.Unmarshal(rawConfig, e); err != nil {
-		return err
+		return errors.Wrap(err, "cannot unmarshal config")
 	}
 
 	k, err := registry.OpenKey(registry.LOCAL_MACHINE, `SOFTWARE\Wow6432Node\Blizzard Entertainment\World of Warcraft`, registry.QUERY_VALUE)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "cannot find WoW install directory")
 	}
 	defer k.Close()
 
 	s, _, err := k.GetStringValue("InstallPath")
 	if err != nil {
-		return err
+		return errors.Wrap(err, "cannot find WoW install directory")
 	}
 	e.addon = filepath.Join(s, "Interface", "AddOns")
 
@@ -61,17 +62,17 @@ func (e *elvui) init(configPath string) error {
 func (e *elvui) getRemoteVersion() error {
 	doc, err := goquery.NewDocument(e.Page)
 	if err != nil {
-		return err
+		return errors.Wrapf(err, "cannot parse url: %s", e.Page)
 	}
 
 	sel := doc.Find(e.Versionselector)
 	if sel == nil {
-		return fmt.Errorf("Version not found at %s", e.Page)
+		return errors.Errorf("version not found at %s", e.Page)
 	}
 
-	span := sel.Text()
+	span := strings.TrimSpace(sel.Text())
 	if e.remoteVersion, err = strconv.ParseFloat(span, 64); err != nil {
-		return err
+		return errors.Wrapf(err, "cannot parse version number %s", span)
 	}
 
 	return nil
@@ -83,7 +84,7 @@ func (e *elvui) getLocalVersion() error {
 
 	toc, err := os.Open(tocFile)
 	if err != nil {
-		return err
+		return errors.Wrapf(err, "cannot open file %s", tocFile)
 	}
 	defer toc.Close()
 	tocReader := bufio.NewReader(toc)
@@ -93,18 +94,19 @@ func (e *elvui) getLocalVersion() error {
 		if err == io.EOF {
 			break
 		} else if err != nil {
-			return err
+			return errors.Wrapf(err, "cannot read lines from %s", tocFile)
 		}
 		if strings.HasPrefix(line, prefix) {
 			// retard windows need -1
-			if e.localVersion, err = strconv.ParseFloat(line[len(prefix):len(line)-1], 64); err != nil {
-				return err
+			rawVer := strings.TrimSpace(line[len(prefix) : len(line)-1])
+			if e.localVersion, err = strconv.ParseFloat(rawVer, 64); err != nil {
+				return errors.Wrapf(err, "cannot parse version number %s", rawVer)
 			}
 			return nil
 		}
 	}
 
-	return fmt.Errorf("Local version not found at %s", tocFile)
+	return errors.Errorf("local version not found at %s", tocFile)
 }
 
 func (e elvui) downloadAndExtract() error {
@@ -113,48 +115,51 @@ func (e elvui) downloadAndExtract() error {
 
 	response, err := http.Get(dlLink)
 	if err != nil {
-		return err
+		return errors.Wrapf(err, "cannot download file url %s", dlLink)
 	}
 	defer response.Body.Close()
 	// hope tukui don't overflow my memory
 	respBytes, err := ioutil.ReadAll(response.Body)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "cannot read response")
 	}
 	readerBytes := bytes.NewReader(respBytes)
 	// zip work
 	zipReader, err := zip.NewReader(readerBytes, response.ContentLength)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "cannot create zip reader")
 	}
 
 	// remove older directories
 	for _, dir := range e.Directories {
-		if err := os.RemoveAll(filepath.Join(e.addon, dir)); err != nil {
-			return err
+		addonDir := filepath.Join(e.addon, dir)
+		if err := os.RemoveAll(addonDir); err != nil {
+			return errors.Wrapf(err, "cannot remove directory %s", addonDir)
 		}
 	}
 
 	for _, f := range zipReader.File {
 		if f.FileInfo().IsDir() {
-			if err := os.MkdirAll(filepath.Join(e.addon, f.Name), f.Mode()); err != nil {
-				return err
+			addonDir := filepath.Join(e.addon, f.Name)
+			if err := os.MkdirAll(addonDir, f.Mode()); err != nil {
+				return errors.Wrapf(err, "cannot create directory %s", addonDir)
 			}
 		} else {
 			// open file inside zip for copy
 			fileInZip, err := f.Open()
 			if err != nil {
-				return err
+				return errors.Wrapf(err, "cannot open file %s inside zip", f.Name)
 			}
 			// create local file
-			fileLocal, err := os.Create(filepath.Join(e.addon, f.Name))
+			localName := filepath.Join(e.addon, f.Name)
+			fileLocal, err := os.Create(localName)
 			if err != nil {
-				return err
+				return errors.Wrapf(err, "cannot create file %s", localName)
 			}
 			// copy contents over
 			_, err = io.Copy(fileLocal, fileInZip)
 			if err != nil {
-				return err
+				return errors.Wrapf(err, "cannot extract content from %s to %s", f.Name, localName)
 			}
 
 			fileLocal.Close()
@@ -168,19 +173,19 @@ func (e elvui) downloadAndExtract() error {
 func main() {
 	conf := elvui{localName: "ElvUI"}
 	if err := conf.init("config.json"); err != nil {
-		log.Fatal(err)
+		log.Fatalf("Fatal: %+v\n", err)
 	}
 
 	if err := conf.getLocalVersion(); err != nil {
-		log.Fatal(err)
+		log.Fatalf("Fatal: %+v\n", err)
 	}
 	if err := conf.getRemoteVersion(); err != nil {
-		log.Fatal(err)
+		log.Fatalf("Fatal: %+v\n", err)
 	}
 	if conf.remoteVersion > conf.localVersion {
 		log.Printf("Upgrading %.2f->%.2f\n", conf.localVersion, conf.remoteVersion)
 		if err := conf.downloadAndExtract(); err != nil {
-			log.Fatal(err)
+			log.Fatalf("Fatal: %+v\n", err)
 		}
 		log.Println("Success")
 	} else {