Fixed client error handling and README.md example usage

Author: nikitaksv

README.md

@@ -53,8 +53,11 @@ func main() {
 		CountryCode: "RU",
 	})
 	if err != nil {
+		if serviceErr, ok := err.(*apidq.ErrorResponse); ok {
+			fmt.Printf("Code: %d; Message: %s", serviceErr.Code, serviceErr.Message)
+		}
 		panic(err)
-    }
+	}
 
 	fmt.Println(cleanRsp.Address.Address) // -- print: г Москва, пл Спартаковская
 }

client.go

@@ -11,6 +11,8 @@ import (
 	"net/url"
 	"strings"
 	"time"
+
+	"github.com/pkg/errors"
 )
 
 const (
@@ -180,18 +182,21 @@ func (c *Client) do(_ context.Context, req *http.Request, v interface{}) (rsp *h
 		if rsp.StatusCode != 200 {
 			errRsp := &ErrorResponse{}
 			decErr := json.Unmarshal(body, errRsp)
-			if decErr == nil {
+			if decErr == nil && errRsp.Code != 0 && errRsp.Message != "" {
 				return nil, errRsp
 			}
-			return nil, decErr
+			if decErr == nil {
+				decErr = errors.New("invalid ErrorResponse struct")
+			}
+			return nil, errors.WithMessage(decErr, string(body))
 		}
 
 		decErr := json.Unmarshal(body, v)
 		if decErr == nil {
 			return rsp, nil
 		}
 
-		return nil, decErr
+		return nil, errors.WithMessage(decErr, string(body))
 	}
 
 	return rsp, nil

client_test.go

@@ -7,6 +7,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 
 	"github.com/nikitaksv/apidq-client-go/dto/address"
@@ -44,6 +45,82 @@ func NewTestClient(h http.HandlerFunc) (*Client, *httptest.Server) {
 	return c.WithAuth(TestAPIKey), s
 }
 
+func TestClientHost(t *testing.T) {
+	c, err := NewClient(http.DefaultClient, "http://no-connect-url.local:9999")
+	if err != nil {
+		panic(err)
+	}
+
+	_, _, err = c.Address.Clean(context.Background(), &address.CleanRequest{})
+	if err == nil {
+		t.Fatal(errors.New("need network error"))
+	}
+	if !strings.Contains(err.Error(), "dial tcp: lookup no-connect-url.local: no such host") {
+		t.Fatal(err.Error())
+	}
+}
+
+func TestClientIncorrectError(t *testing.T) {
+	invalidErrRsp := []byte(`{"code":"invalid code type","message":false}`)
+	c, s := NewTestClient(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(400)
+		_, err := w.Write(invalidErrRsp)
+		if err != nil {
+			panic(err)
+		}
+	})
+
+	defer s.Close()
+	_, _, err := c.Address.Clean(context.Background(), &address.CleanRequest{})
+	if err == nil {
+		t.Fatal(errors.New("need ErrorResponse"))
+	}
+	if err.Error() != "{\"code\":\"invalid code type\",\"message\":false}: json: cannot unmarshal string into Go struct field ErrorResponse.code of type int" {
+		t.Fatal(err)
+	}
+}
+func TestClientEmptyErrorResponse(t *testing.T) {
+	invalidErrRsp := []byte(`{"asd":"qwe"}`)
+	c, s := NewTestClient(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(400)
+		_, err := w.Write(invalidErrRsp)
+		if err != nil {
+			panic(err)
+		}
+	})
+
+	defer s.Close()
+	_, _, err := c.Address.Clean(context.Background(), &address.CleanRequest{})
+	if err == nil {
+		t.Fatal(errors.New("need error"))
+	}
+
+	if err.Error() != "{\"asd\":\"qwe\"}: invalid ErrorResponse struct" {
+		t.Fatal(err)
+	}
+}
+
+func TestClientIncorrectResponse(t *testing.T) {
+	invalidRsp := []byte(`{"origin":"123","area":false}`)
+	c, s := NewTestClient(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		_, err := w.Write(invalidRsp)
+		if err != nil {
+			panic(err)
+		}
+	})
+
+	defer s.Close()
+	_, _, err := c.Address.Clean(context.Background(), &address.CleanRequest{})
+	if err == nil {
+		t.Fatal(errors.New("need error"))
+	}
+	if err.Error() != "{\"origin\":\"123\",\"area\":false}: json: cannot unmarshal bool into Go struct field CleanResponse.area of type address.Part" {
+		t.Fatal(err)
+	}
+
+}
+
 func TestAuth(t *testing.T) {
 	client, tS := NewTestClient(func(w http.ResponseWriter, r *http.Request) {})
 	defer tS.Close()

go.mod

@@ -2,4 +2,7 @@ module github.com/nikitaksv/apidq-client-go
 
 go 1.15
 
-require github.com/stretchr/testify v1.7.0
+require (
+	github.com/pkg/errors v0.9.1
+	github.com/stretchr/testify v1.7.0
+)

go.sum

@@ -1,5 +1,7 @@
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=