Use gabs package to improve parsing of json data

editions.go

@@ -1,15 +1,19 @@
 package gol
 
 import (
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
 	"strings"
+
+	"github.com/Jeffail/gabs/v2"
 )
 
-type Book map[string]interface{}
+type Book struct {
+	Container
+	Authors []string
+}
 
 // GetEdition returns a book from its open library id
 func GetEdition(olid string) (b Book, err error) {
@@ -21,11 +25,16 @@ func GetEdition(olid string) (b Book, err error) {
 
 	defer resp.Body.Close()
 	bodyBytes, _ := ioutil.ReadAll(resp.Body)
-	json.Unmarshal(bodyBytes, &b)
+	b.Container, err = gabs.ParseJSON(bodyBytes)
+	if err != nil {
+		return b, err
+	}
 
-	if error, ok := b["error"]; ok {
-		return b, fmt.Errorf("GetEdition: Error fetching book; %s", error)
+	// verify if an error field is present in the returned data
+	if err := HasError(b.Container); err != nil {
+		return b, err
 	}
+
 	return
 }
 
@@ -50,23 +59,37 @@ func GetEditionISBN(isbnid string) (b Book, err error) {
 
 	defer resp.Body.Close()
 	bodyBytes, _ := ioutil.ReadAll(resp.Body)
-	json.Unmarshal(bodyBytes, &b)
-	if error, ok := b["error"]; ok {
-		return b, fmt.Errorf("Book/Edition not found; %s", error)
+	b.Container, err = gabs.ParseJSON(bodyBytes)
+	if err != nil {
+		return b, err
 	}
+	if err != nil {
+		return b, err
+	}
+
+	// verify if an error field is present in the returned data
+	if err := HasError(b.Container); err != nil {
+		return b, err
+	}
+
 	return
 }
 
-/*
 // KeyAuthors returns array of all authors keys
-func (b Book) KeyAuthors() []string {
-	a := make([]string, len(b.AuthorsKey))
-	for i, AuthorKey := range b.AuthorsKey {
-		a[i] = AuthorKey.Key[9:]
+func (b *Book) KeyAuthors() (err error) {
+	for _, child := range b.S("authors").Children() {
+		for _, v := range child.ChildrenMap() {
+			b.Authors = append(b.Authors, v.Data().(string))
+		}
+	}
+
+	if len(b.Authors) == 0 {
+		return fmt.Errorf("Could not find any authors")
 	}
-	return a
+	return
 }
 
+/*
 // Authors returns all the information related to the book's authors
 func (b Book) Authors() (a []Author, err error) {
 	return Authors(b)

editions_test.go

@@ -36,14 +36,32 @@ func TestGetEditionISBN(t *testing.T) {
 		})
 	}
 }
+func TestEditionKeyAuthors(t *testing.T) {
+	t.Parallel()
+	t.Run("Existing Author", func(t *testing.T) {
+		t.Parallel()
+		b, _ := gol.GetEdition("OL4554174M")
+		ok := b.KeyAuthors()
+		if ok != nil {
+			t.Fatalf("KeyAuthors() did not return authors for an existing book")
+		}
+	})
 
-//func TestEditionKeyAuthors(t *testing.T) {
-//a := b.KeyAuthors()
-//if !cmp.Equal(a, []string{"OL236174A"}) {
-//t.Errorf("Unexpected returned array. Expecting [OL18295A] got %v", a)
-//}
-//}
+	t.Run("Non-Existing Author", func(t *testing.T) {
+		t.Parallel()
+		b, _ := gol.GetEdition("OL0000000M")
+		ok := b.KeyAuthors()
+		if ok == nil {
+			t.Fatalf("KeyAuthors() did not return an error for non existing book")
+		}
+	})
+
+	//if !cmp.Equal(a, []string{"OL236174A"}) {
+	//	t.Errorf("Unexpected returned array. Expecting [OL18295A] got %v", a)
+	//}
+}
 
+/*
 //func TestEditionAuthors(t *testing.T) {
 //tr, err := editions[0].Authors()
 //if err != nil {
@@ -53,3 +71,4 @@ func TestGetEditionISBN(t *testing.T) {
 //t.Errorf("Expected set of authors incorrect")
 //}
 //}
+*/

go.mod

@@ -2,4 +2,4 @@ module github.com/Open-pi/gol
 
 go 1.16
 
-require github.com/google/go-cmp v0.5.5
+require github.com/Jeffail/gabs/v2 v2.6.1

go.sum

@@ -1,4 +1,2 @@
-github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
-github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+github.com/Jeffail/gabs/v2 v2.6.1 h1:wwbE6nTQTwIMsMxzi6XFQQYRZ6wDc1mSdxoAN+9U4Gk=
+github.com/Jeffail/gabs/v2 v2.6.1/go.mod h1:xCn81vdHKxFUuWWAaD5jCTQDNPBMh5pPs9IJ+NcziBI=

gol.go

@@ -5,4 +5,19 @@ gol uses the WorkAPI, the EditionAPI, and the CoverAPI
 */
 package gol
 
-type JsonData map[string]interface{}
+import (
+	"fmt"
+
+	"github.com/Jeffail/gabs/v2"
+)
+
+type Container = *gabs.Container
+
+func HasError(data Container) error {
+
+	// verify if an error field is present in the returned data
+	if err, ok := data.Path("error").Data().(string); ok {
+		return fmt.Errorf("Error fetching data; %s", err)
+	}
+	return nil
+}