improved error handling in middleware

authorisation/middleware.go

@@ -3,10 +3,11 @@ package authorisation
 import (
 	"context"
 	"errors"
+	"fmt"
 	"net/http"
 	"strings"
 
-	"github.com/ONSdigital/dp-api-clients-go/headers"
+	"github.com/ONSdigital/dp-api-clients-go/v2/headers"
 	"github.com/ONSdigital/dp-authorisation/v2/identityclient"
 	"github.com/ONSdigital/dp-authorisation/v2/jwt"
 	"github.com/ONSdigital/dp-authorisation/v2/permissions"
@@ -200,15 +201,21 @@ func (m PermissionCheckMiddleware) Parse(token string) (*permsdk.EntityData, err
 }
 
 // GetCollectionIdAttribute provides an implementation of GetAttributesFromRequest. Retrieves and returns
-// header 'Collection-Id' from the request if it exists, otherwise returns an empty map. Never returns an
-// error as the header is not mandatory
+// header 'Collection-Id' from the request if it exists, otherwise returns an empty map.
+// It may return an error only if the header cannot be retrieved by some other reason (e.g. nil request).
 func GetCollectionIDAttribute(req *http.Request) (map[string]string, error) {
 	attributes := make(map[string]string, 0)
 
-	collectionIDAttribute, _ := headers.GetCollectionID(req)
-	if collectionIDAttribute != "" {
-		attributes[collectionIDAttributeKey] = collectionIDAttribute
+	collectionIDAttribute, err := headers.GetCollectionID(req)
+	if err != nil {
+		if err == headers.ErrHeaderNotFound {
+			// empty header is allowed (no value returned in attributes map for CollectionID)
+			return attributes, nil
+		}
+		// any other error must be returned
+		return nil, fmt.Errorf("error getting Collection-Id header from request: %w", err)
 	}
 
+	attributes[collectionIDAttributeKey] = collectionIDAttribute
 	return attributes, nil
 }

authorisation/middleware_test.go

@@ -456,6 +456,19 @@ func TestGetCollectionIdAttribute_NoCollectionIdHeader(t *testing.T) {
 			})
 		})
 	})
+
+	Convey("Given a nil request", t, func() {
+		var request *http.Request = nil
+
+		Convey("When the function is called", func() {
+			_, err := authorisation.GetCollectionIDAttribute(request)
+
+			Convey("Then the expected error is returned", func() {
+				So(err, ShouldNotBeNil)
+				So(err.Error(), ShouldResemble, "error getting Collection-Id header from request: error setting request header request was nil")
+			})
+		})
+	})
 }
 
 func TestMiddleware_NewMiddlewareFromConfig_JWTKeys(t *testing.T) {

go.mod

@@ -3,7 +3,6 @@ module github.com/ONSdigital/dp-authorisation/v2
 go 1.19
 
 require (
-	github.com/ONSdigital/dp-api-clients-go v1.43.0
 	github.com/ONSdigital/dp-api-clients-go/v2 v2.159.1
 	github.com/ONSdigital/dp-healthcheck v1.3.0
 	github.com/ONSdigital/dp-net v1.4.1
@@ -17,6 +16,7 @@ require (
 )
 
 require (
+	github.com/ONSdigital/dp-api-clients-go v1.43.0 // indirect
 	github.com/aws/aws-sdk-go v1.44.75 // indirect
 	github.com/fatih/color v1.13.0 // indirect
 	github.com/gopherjs/gopherjs v1.17.2 // indirect