add better generate

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

vendor/github.com/genuinetools/reg/registry/authchallenge_test.go

@@ -0,0 +1,55 @@
+package registry
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+)
+
+type authServiceMock struct {
+	service string
+	realm   string
+	scope   []string
+}
+
+type challengeTestCase struct {
+	header      string
+	errorString string
+	value       authServiceMock
+}
+
+func (asm authServiceMock) equalTo(v *authService) bool {
+	if asm.service != v.Service {
+		return false
+	}
+	if reflect.DeepEqual(asm.scope, v.Scope) {
+		return false
+	}
+	if asm.realm != v.Realm.String() {
+		return false
+	}
+	return true
+}
+
+func TestParseChallenge(t *testing.T) {
+	challengeHeaderCases := []challengeTestCase{
+		{
+			header: `Bearer realm="https://foobar.com/api/v1/token",service=foobar.com,scope=""`,
+			value: authServiceMock{
+				service: "foobar.com",
+				realm:   "https://foobar.com/api/v1/token",
+			},
+		},
+	}
+
+	for _, tc := range challengeHeaderCases {
+		val, err := parseChallenge(tc.header)
+		if err != nil && !strings.Contains(err.Error(), tc.errorString) {
+			t.Fatalf("expected error to contain %v,  got %s", tc.errorString, err)
+		}
+		if !tc.value.equalTo(val) {
+			t.Fatalf("got %v, expected %v", val, tc.value)
+		}
+
+	}
+}