Add support for verification page property (#158)

* Add support for verification page property

1. Property documented [here](https://developers.notion.com/reference/page-property-values#verification)
2. Replace github.com/pkg/errors with native errors package

* linter warnings

* Add verification to property config

* add verification state enum

const.go

@@ -33,6 +33,7 @@ const (
 	PropertyConfigLastEditedBy    PropertyConfigType = "last_edited_by"
 	PropertyConfigStatus          PropertyConfigType = "status"
 	PropertyConfigUniqueID        PropertyConfigType = "unique_id"
+	PropertyConfigVerification    PropertyConfigType = "verification"
 )
 
 const (
@@ -58,6 +59,7 @@ const (
 	PropertyTypeLastEditedBy   PropertyType = "last_edited_by"
 	PropertyTypeStatus         PropertyType = "status"
 	PropertyTypeUniqueID       PropertyType = "unique_id"
+	PropertyTypeVerification   PropertyType = "verification"
 )
 
 const (
@@ -273,3 +275,8 @@ const (
 	RelationSingleProperty RelationConfigType = "single_property"
 	RelationDualProperty   RelationConfigType = "dual_property"
 )
+
+const (
+	VerificationStateVerified   VerificationState = "verified"
+	VerificationStateUnverified VerificationState = "unverified"
+)

database.go

@@ -3,8 +3,8 @@ package notionapi
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
-	"github.com/pkg/errors"
 	"log"
 	"net/http"
 	"time"

go.mod

@@ -1,5 +1,3 @@
 module github.com/jomei/notionapi
 
 go 1.14
-
-require github.com/pkg/errors v0.9.1

go.sum

@@ -1,2 +0,0 @@
-github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
-github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=

object.go

@@ -199,3 +199,16 @@ func (uID UniqueID) String() string {
 	}
 	return fmt.Sprintf("%d", uID.Number)
 }
+
+type VerificationState string
+
+func (vs VerificationState) String() string {
+	return string(vs)
+}
+
+// Verification documented here: https://developers.notion.com/reference/page-property-values#verification
+type Verification struct {
+	State      VerificationState `json:"state"`
+	VerifiedBy *User             `json:"verified_by,omitempty"`
+	Date       *DateObject       `json:"date,omitempty"`
+}

property.go

@@ -4,8 +4,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"time"
-
-	"github.com/pkg/errors"
 )
 
 type PropertyType string
@@ -381,6 +379,20 @@ func (p UniqueIDProperty) GetType() PropertyType {
 	return p.Type
 }
 
+type VerificationProperty struct {
+	ID           ObjectID     `json:"id,omitempty"`
+	Type         PropertyType `json:"type,omitempty"`
+	Verification Verification `json:"verification"`
+}
+
+func (p VerificationProperty) GetID() string {
+	return p.ID.String()
+}
+
+func (p VerificationProperty) GetType() PropertyType {
+	return p.Type
+}
+
 type Properties map[string]Property
 
 func (p *Properties) UnmarshalJSON(data []byte) error {
@@ -417,7 +429,7 @@ func parsePageProperties(raw map[string]interface{}) (map[string]Property, error
 
 			result[k] = p
 		default:
-			return nil, errors.New(fmt.Sprintf("unsupported property format %T", v))
+			return nil, fmt.Errorf("unsupported property format %T", v)
 		}
 	}
 
@@ -471,8 +483,10 @@ func decodeProperty(raw map[string]interface{}) (Property, error) {
 		p = &StatusProperty{}
 	case PropertyTypeUniqueID:
 		p = &UniqueIDProperty{}
+	case PropertyTypeVerification:
+		p = &VerificationProperty{}
 	default:
-		return nil, errors.New(fmt.Sprintf("unsupported property type: %s", raw["type"].(string)))
+		return nil, fmt.Errorf("unsupported property type: %s", raw["type"].(string))
 	}
 
 	return p, nil

property_config.go

@@ -281,6 +281,16 @@ func (i UniqueIDPropertyConfig) GetType() PropertyConfigType {
 	return ""
 }
 
+type VerificationPropertyConfig struct {
+	ID           ObjectID           `json:"id,omitempty"`
+	Type         PropertyConfigType `json:"type,omitempty"`
+	Verification Verification       `json:"verification"`
+}
+
+func (p VerificationPropertyConfig) GetType() PropertyConfigType {
+	return p.Type
+}
+
 type PropertyConfigs map[string]PropertyConfig
 
 func (p *PropertyConfigs) UnmarshalJSON(data []byte) error {
@@ -346,6 +356,8 @@ func parsePropertyConfigs(raw map[string]interface{}) (PropertyConfigs, error) {
 				p = &StatusPropertyConfig{}
 			case PropertyConfigUniqueID:
 				p = &UniqueIDPropertyConfig{}
+			case PropertyConfigVerification:
+				p = &VerificationPropertyConfig{}
 			default:
 
 				return nil, fmt.Errorf("unsupported property type: %s", rawProperty["type"].(string))