feat: standard error structures (#177)

* feat: add standard errors

Author: kindermoumoute

scw/errors.go

@@ -3,7 +3,9 @@ package scw
 import (
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"net/http"
+	"strings"
 
 	"github.com./scaleway/scaleway-sdk-go/internal/errors"
 )
@@ -71,10 +73,137 @@ func hasResponseError(res *http.Response) SdkError {
 		return newErr
 	}
 
-	err := json.NewDecoder(res.Body).Decode(newErr)
+	body, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return errors.Wrap(err, "cannot read error response body")
+	}
+
+	err = json.Unmarshal(body, newErr)
 	if err != nil {
 		return errors.Wrap(err, "could not parse error response body")
 	}
+	stdErr := unmarshalStandardError(newErr.Type, body)
+	if stdErr != nil {
+		return stdErr
+	}
 
 	return newErr
 }
+
+func unmarshalStandardError(errorType string, body []byte) SdkError {
+	var stdErr SdkError
+
+	switch errorType {
+	case "invalid_arguments":
+		stdErr = &InvalidArgumentsError{}
+	case "quotas_exceeded":
+		stdErr = &QuotasExceededError{}
+	case "transient_state":
+		stdErr = &TransientStateError{}
+	case "not_found":
+		stdErr = &ResourceNotFound{}
+	case "permissions_denied":
+		stdErr = &PermissionsDeniedError{}
+	default:
+		return nil
+	}
+
+	err := json.Unmarshal(body, stdErr)
+	if err != nil {
+		return errors.Wrap(err, "could not parse error %s response body", errorType)
+	}
+
+	return stdErr
+}
+
+type InvalidArgumentsError struct {
+	Details []struct {
+		ArgumentName string `json:"argument_name"`
+		Reason       string `json:"reason"`
+		HelpMessage  string `json:"help_message"`
+	} `json:"details"`
+}
+
+// IsScwSdkError implements the SdkError interface
+func (e *InvalidArgumentsError) IsScwSdkError() {}
+func (e *InvalidArgumentsError) Error() string {
+	invalidArgs := make([]string, len(e.Details))
+	for i, d := range e.Details {
+		invalidArgs[i] = d.ArgumentName
+		switch d.Reason {
+		case "unknown":
+			invalidArgs[i] += " is invalid for unexpected reason"
+		case "required":
+			invalidArgs[i] += " is required"
+		case "format":
+			invalidArgs[i] += " is wrongly formatted"
+		case "constraint":
+			invalidArgs[i] += " does not respect constraint"
+		}
+		if d.HelpMessage != "" {
+			invalidArgs[i] += ", " + d.HelpMessage
+		}
+	}
+
+	return "scaleway-sdk-go: invalid argument(s): " + strings.Join(invalidArgs, "; ")
+}
+
+type QuotasExceededError struct {
+	Details []struct {
+		Resource string `json:"resource"`
+		Quota    uint32 `json:"quota"`
+		Current  uint32 `json:"current"`
+	} `json:"details"`
+}
+
+// IsScwSdkError implements the SdkError interface
+func (e *QuotasExceededError) IsScwSdkError() {}
+func (e *QuotasExceededError) Error() string {
+	invalidArgs := make([]string, len(e.Details))
+	for i, d := range e.Details {
+		invalidArgs[i] = fmt.Sprintf("%s has reached its quota (%d/%d)", d.Resource, d.Current, d.Current)
+	}
+
+	return "scaleway-sdk-go: quota exceeded(s): " + strings.Join(invalidArgs, "; ")
+}
+
+type PermissionsDeniedError struct {
+	Details []struct {
+		Resource string `json:"resource"`
+		Action   string `json:"action"`
+	} `json:"details"`
+}
+
+// IsScwSdkError implements the SdkError interface
+func (e *PermissionsDeniedError) IsScwSdkError() {}
+func (e *PermissionsDeniedError) Error() string {
+	invalidArgs := make([]string, len(e.Details))
+	for i, d := range e.Details {
+		invalidArgs[i] = fmt.Sprintf("%s %s", d.Action, d.Resource)
+	}
+
+	return "scaleway-sdk-go: insufficient permissions: " + strings.Join(invalidArgs, "; ")
+}
+
+type TransientStateError struct {
+	Resource     string `json:"resource"`
+	ResourceID   string `json:"resource_id"`
+	CurrentState string `json:"current_state"`
+}
+
+// IsScwSdkError implements the SdkError interface
+func (e *TransientStateError) IsScwSdkError() {}
+func (e *TransientStateError) Error() string {
+	return fmt.Sprintf("scaleway-sdk-go: resource %s with ID %s is in a transient state: %s", e.Resource, e.ResourceID, e.CurrentState)
+}
+
+type ResourceNotFound struct {
+	Resource   string `json:"resource"`
+	ResourceID string `json:"resource_id"`
+}
+
+// IsScwSdkError implements the SdkError interface
+func (e *ResourceNotFound) IsScwSdkError() {}
+func (e *ResourceNotFound) Error() string {
+	return fmt.Sprintf("scaleway-sdk-go: resource %s with ID %s is not found", e.Resource, e.ResourceID)
+}