fix: remove check constraint

Tests now use the new httpclient to properly handle empty strings vs
<nil> strings (where the value is omitted in the JSON request).

.docker/Dockerfile-build

@@ -10,6 +10,9 @@ ADD go.sum go.sum
 ADD proto/go.mod proto/go.mod
 ADD proto/go.sum proto/go.sum
 
+ADD internal/httpclient-next/go.mod internal/httpclient-next/go.mod
+ADD internal/httpclient-next/go.sum internal/httpclient-next/go.sum
+
 ENV CGO_ENABLED 1
 
 RUN go mod download

go.mod

@@ -5,6 +5,7 @@ replace (
 	github.com/gogo/protobuf => github.com/gogo/protobuf v1.3.2
 	github.com/mattn/go-sqlite3 => github.com/mattn/go-sqlite3 v1.14.10
 	github.com/oleiade/reflections => github.com/oleiade/reflections v1.0.1
+	github.com/ory/keto/internal/httpclient-next => ./internal/httpclient-next
 	github.com/ory/keto/proto => ./proto
 	github.com/soheilhy/cmux => github.com/soheilhy/cmux v0.1.5-0.20210114230657-cdd3331e3e7c
 )
@@ -27,6 +28,7 @@ require (
 	github.com/ory/graceful v0.1.3
 	github.com/ory/herodot v0.9.13
 	github.com/ory/jsonschema/v3 v3.0.7
+	github.com/ory/keto/internal/httpclient-next v0.0.0-00010101000000-000000000000
 	github.com/ory/keto/proto v0.0.0-00010101000000-000000000000
 	github.com/ory/x v0.0.463
 	github.com/pelletier/go-toml v1.9.5

internal/e2e/cases_test.go

@@ -49,6 +49,36 @@ func runCases(c client, m *namespaceTestManager) func(*testing.T) {
 			assert.True(t, c.check(t, tuple))
 		})
 
+		t.Run("case=creates tuple with empty IDs", func(t *testing.T) {
+			n := &namespace.Namespace{Name: t.Name()}
+			m.add(t, n)
+
+			tuples := []*ketoapi.RelationTuple{{
+				Namespace: n.Name,
+				Object:    "",
+				Relation:  "access",
+				SubjectID: x.Ptr(""),
+			}, {
+				Namespace: n.Name,
+				Object:    "",
+				Relation:  "access",
+				SubjectSet: &ketoapi.SubjectSet{
+					Namespace: n.Name,
+					Object:    "",
+					Relation:  "access",
+				},
+			}}
+
+			for _, tp := range tuples {
+				c.createTuple(t, tp)
+				// try the check API to see whether the tuple is interpreted correctly
+				assert.True(t, c.check(t, tp))
+			}
+
+			resp := c.queryTuple(t, &ketoapi.RelationQuery{Namespace: &n.Name})
+			assert.ElementsMatch(t, tuples, resp.RelationTuples)
+		})
+
 		t.Run("case=check subjectSet relations", func(t *testing.T) {
 			n := &namespace.Namespace{Name: t.Name()}
 			m.add(t, n)
@@ -216,7 +246,7 @@ func runCases(c client, m *namespaceTestManager) func(*testing.T) {
 
 			c.deleteAllTuples(t, q)
 			resp = c.queryTuple(t, q)
-			assert.Equal(t, len(resp.RelationTuples), 0)
+			assert.Equal(t, 0, len(resp.RelationTuples))
 		})
 
 		t.Run("case=returns error with status code on unknown namespace", func(t *testing.T) {

internal/e2e/full_suit_test.go

@@ -7,8 +7,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/ory/keto/ketoapi"
-
 	"github.com/ory/herodot"
 	"github.com/ory/x/cmdx"
 	prometheus "github.com/ory/x/prometheusx"
@@ -21,6 +19,7 @@ import (
 	"github.com/ory/keto/internal/relationtuple"
 	"github.com/ory/keto/internal/x"
 	"github.com/ory/keto/internal/x/dbx"
+	"github.com/ory/keto/ketoapi"
 )
 
 type (