Feature/error management

07-behaviour_error_handling/cmd/beers-cli/main.go

@@ -1,28 +1,19 @@
 package main
 
 import (
-	"flag"
-
 	"github.com/CodelyTV/golang-examples/07-behaviour_error_handling/internal/storage/ontario"
 
-	beerscli "github.com/CodelyTV/golang-examples/07-behaviour_error_handling/internal"
 	"github.com/CodelyTV/golang-examples/07-behaviour_error_handling/internal/cli"
 	"github.com/CodelyTV/golang-examples/07-behaviour_error_handling/internal/storage/csv"
 	"github.com/spf13/cobra"
 )
 
 func main() {
 
-	csvData := flag.Bool("csv", false, "load data from csv")
-	flag.Parse()
-	var repo beerscli.BeerRepo
-	repo = csv.NewRepository()
-
-	if !*csvData {
-		repo = ontario.NewOntarioRepository()
-	}
+	repoAPI := csv.NewRepository()
+	repoCSV := ontario.NewOntarioRepository()
 
 	rootCmd := &cobra.Command{Use: "beers-cli"}
-	rootCmd.AddCommand(cli.InitBeersCmd(repo))
+	rootCmd.AddCommand(cli.InitBeersCmd(repoAPI, repoCSV))
 	rootCmd.Execute()
 }

07-behaviour_error_handling/internal/cli/beers.go

@@ -17,22 +17,36 @@ type CobraFn func(cmd *cobra.Command, args []string)
 const idFlag = "id"
 
 // InitBeersCmd initialize beers command
-func InitBeersCmd(repository beerscli.BeerRepo) *cobra.Command {
+func InitBeersCmd(repoAPI beerscli.BeerRepo, repoCSV beerscli.BeerRepo) *cobra.Command {
 	beersCmd := &cobra.Command{
 		Use:   "beers",
 		Short: "Print data about beers",
-		Run:   runBeersFn(repository),
+		Run:   runBeersFn(repoAPI, repoCSV),
 	}
 
 	beersCmd.Flags().StringP(idFlag, "i", "", "id of the beer")
+	beersCmd.Flags().Bool("csv", false, "load data from csv")
 
 	return beersCmd
 }
 
-func runBeersFn(repository beerscli.BeerRepo) CobraFn {
+func runBeersFn(repoAPI beerscli.BeerRepo, repoCSV beerscli.BeerRepo) CobraFn {
 	return func(cmd *cobra.Command, args []string) {
+		var repository beerscli.BeerRepo
+		useCSV, _ := cmd.Flags().GetBool("csv")
+		if useCSV {
+			repository = repoAPI
+		} else {
+			repository = repoCSV
+		}
 		beers, err := repository.GetBeers()
 		if errors.IsDataUnreacheable(err) {
+			log.Printf("https://github.com/caleeli/golang-examples.git/issues/new?assignees=&labels=&template=dataunreachable.md&title=")
+		}
+		if errors.IsLoadCSVError(err) {
+			log.Printf("https://github.com/caleeli/golang-examples.git/issues/new?assignees=&labels=&template=loadcsv.md&title=")
+		}
+		if err != nil {
 			log.Fatal(err)
 		}
 

07-behaviour_error_handling/internal/errors/load_csv_errors.go

@@ -0,0 +1,28 @@
+package errors
+
+import (
+	"github.com/pkg/errors"
+)
+
+type loadCSVError struct {
+	error
+}
+
+// WrapLoadCSVError returns an error which wraps err that satisfies
+// IsLoadCSVError()
+func WrapLoadCSVError(err error, format string, args ...interface{}) error {
+	return &loadCSVError{errors.Wrapf(err, format, args...)}
+}
+
+// NewLoadCSVError returns an error which satisfies IsLoadCSVError()
+func NewLoadCSVError(format string, args ...interface{}) error {
+	return &loadCSVError{errors.Errorf(format, args...)}
+}
+
+// IsLoadCSVError reports whether err was created with LoadCSVErrorf() or
+// NewLoadCSVError()
+func IsLoadCSVError(err error) bool {
+	err = errors.Cause(err)
+	_, ok := err.(*loadCSVError)
+	return ok
+}

07-behaviour_error_handling/internal/storage/csv/repository.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	beerscli "github.com/CodelyTV/golang-examples/07-behaviour_error_handling/internal"
+	"github.com/CodelyTV/golang-examples/07-behaviour_error_handling/internal/errors"
 )
 
 type repository struct {
@@ -19,15 +20,27 @@ func NewRepository() beerscli.BeerRepo {
 
 // GetBeers fetch beers data from csv
 func (r *repository) GetBeers() ([]beerscli.Beer, error) {
-	f, _ := os.Open("07-behaviour_error_handling/data/beers.csv")
+	file := "07-behaviour_error_handling/data/beers.csv"
+	f, err := os.Open(file)
+	if err != nil {
+		return nil, errors.WrapLoadCSVError(err, "Unable to open %s", file)
+	}
+
 	reader := bufio.NewReader(f)
 
 	var beers []beerscli.Beer
 
-	for line := readLine(reader); line != nil; line = readLine(reader) {
+	for line, err := readLine(reader); line != nil; line, err = readLine(reader) {
+		if err != nil {
+			return nil, errors.WrapLoadCSVError(err, "Failed reading of line %d", line)
+		}
+
 		values := strings.Split(string(line), ",")
 
-		productID, _ := strconv.Atoi(values[0])
+		productID, err := strconv.Atoi(values[0])
+		if err != nil {
+			return nil, errors.WrapLoadCSVError(err, "Invalid product ID '%s'", values[0])
+		}
 
 		beer := beerscli.NewBeer(
 			productID,
@@ -45,7 +58,7 @@ func (r *repository) GetBeers() ([]beerscli.Beer, error) {
 	return beers, nil
 }
 
-func readLine(reader *bufio.Reader) (line []byte) {
-	line, _, _ = reader.ReadLine()
+func readLine(reader *bufio.Reader) (line []byte, err error) {
+	line, _, err = reader.ReadLine()
 	return
 }