cloudflare: update RequestError to expose Messages

The messages field isn't really used broadly in the API as it was designed for
informational feedback as opposed to errors, however, the page rules endpoint
uses it to communicate validation failures. For these messages to be raised in
other tools, namely the Terraform provider, it needs a dedicated field on the
struct and to be included in the `Error()` method.

Closes cloudflare/terraform-provider-cloudflare#1579

cloudflare.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -16,8 +17,6 @@ import (
 	"strings"
 	"time"
 
-	"errors"
-
 	"golang.org/x/time/rate"
 )
 
@@ -347,6 +346,7 @@ func (api *API) makeRequestWithAuthTypeAndHeadersComplete(ctx context.Context, m
 			Errors:        errBody.Errors,
 			ErrorCodes:    errCodes,
 			ErrorMessages: errMsgs,
+			Messages:      errBody.Messages,
 		}
 
 		switch resp.StatusCode {

errors.go

@@ -70,6 +70,9 @@ type Error struct {
 	// ErrorMessages is a list of all the error codes.
 	ErrorMessages []string
 
+	// Messages is a list of informational messages provided by the endpoint.
+	Messages []ResponseInfo
+
 	// RayID is the internal identifier for the request that was made.
 	RayID string
 }
@@ -90,7 +93,21 @@ func (e Error) Error() string {
 		errMessages = append(errMessages, m)
 	}
 
-	return errString + strings.Join(errMessages, ", ")
+	msgs := []string{}
+	for _, m := range e.Messages {
+		msgs = append(msgs, m.Message)
+	}
+
+	errString += strings.Join(errMessages, ", ")
+
+	// `Messages` is primarily used for additional validation failure notes in
+	// page rules. This shouldn't be used going forward but instead, use the
+	// error fields appropriately.
+	if len(msgs) > 0 {
+		errString += "\n" + strings.Join(msgs, "  \n")
+	}
+
+	return errString
 }
 
 // RequestError is for 4xx errors that we encounter not covered elsewhere
@@ -119,6 +136,10 @@ func (e RequestError) InternalErrorCodeIs(code int) bool {
 	return e.cloudflareError.InternalErrorCodeIs(code)
 }
 
+func (e RequestError) Messages() []ResponseInfo {
+	return e.cloudflareError.Messages
+}
+
 func (e RequestError) RayID() string {
 	return e.cloudflareError.RayID
 }