feat: expose function to generate OPL

cmd/namespace/.snapshots/TestGenerateOPLConfig-case=empty.json

@@ -0,0 +1 @@
+"import { Namespace, SubjectSet, Context } from '@ory/keto-namespace-types'\n\n// Declare new namespaces as classes that implement `Namespace`"

cmd/namespace/.snapshots/TestGenerateOPLConfig-case=many.json

@@ -0,0 +1 @@
+"import { Namespace, SubjectSet, Context } from '@ory/keto-namespace-types'\n\n// Declare new namespaces as classes that implement `Namespace`\nclass one implements Namespace {\n  related: {\n    // Define relations to other objects here.\n    // Examples:\n    //\n    // parents: (File | Folder)[]\n    // viewers: SubjectSet\u003cGroup, \"members\"\u003e[]\n  }\n\n  permits = {\n    // Define permissions here. These can be derived from the relations above.\n    // Examples:\n    //\n    // view: (ctx: Context): boolean =\u003e\n    //  this.related.viewers.includes(ctx.subject) ||\n    //  this.related.parents.traverse((p) =\u003e p.permits.view(ctx)),\n  }\n}\n\nclass two implements Namespace {\n  related: {\n    // Define relations to other objects here.\n    // Examples:\n    //\n    // parents: (File | Folder)[]\n    // viewers: SubjectSet\u003cGroup, \"members\"\u003e[]\n  }\n\n  permits = {\n    // Define permissions here. These can be derived from the relations above.\n    // Examples:\n    //\n    // view: (ctx: Context): boolean =\u003e\n    //  this.related.viewers.includes(ctx.subject) ||\n    //  this.related.parents.traverse((p) =\u003e p.permits.view(ctx)),\n  }\n}\n\nclass three implements Namespace {\n  related: {\n    // Define relations to other objects here.\n    // Examples:\n    //\n    // parents: (File | Folder)[]\n    // viewers: SubjectSet\u003cGroup, \"members\"\u003e[]\n  }\n\n  permits = {\n    // Define permissions here. These can be derived from the relations above.\n    // Examples:\n    //\n    // view: (ctx: Context): boolean =\u003e\n    //  this.related.viewers.includes(ctx.subject) ||\n    //  this.related.parents.traverse((p) =\u003e p.permits.view(ctx)),\n  }\n}\n"

cmd/namespace/.snapshots/TestGenerateOPLConfig-case=one.json

@@ -0,0 +1 @@
+"import { Namespace, SubjectSet, Context } from '@ory/keto-namespace-types'\n\n// Declare new namespaces as classes that implement `Namespace`\nclass one implements Namespace {\n  related: {\n    // Define relations to other objects here.\n    // Examples:\n    //\n    // parents: (File | Folder)[]\n    // viewers: SubjectSet\u003cGroup, \"members\"\u003e[]\n  }\n\n  permits = {\n    // Define permissions here. These can be derived from the relations above.\n    // Examples:\n    //\n    // view: (ctx: Context): boolean =\u003e\n    //  this.related.viewers.includes(ctx.subject) ||\n    //  this.related.parents.traverse((p) =\u003e p.permits.view(ctx)),\n  }\n}\n"

cmd/namespace/config_template/namespaces.ts.tmpl

@@ -0,0 +1,22 @@
+import { Namespace, SubjectSet, Context } from '@ory/keto-namespace-types'
+
+// Declare new namespaces as classes that implement `Namespace`{{ range .Namespaces }}
+class {{ . }} implements Namespace {
+  related: {
+    // Define relations to other objects here.
+    // Examples:
+    //
+    // parents: (File | Folder)[]
+    // viewers: SubjectSet<Group, "members">[]
+  }
+
+  permits = {
+    // Define permissions here. These can be derived from the relations above.
+    // Examples:
+    //
+    // view: (ctx: Context): boolean =>
+    //  this.related.viewers.includes(ctx.subject) ||
+    //  this.related.parents.traverse((p) => p.permits.view(ctx)),
+  }
+}
+{{ end }}

cmd/namespace/opl_generate.go

@@ -0,0 +1,25 @@
+package namespace
+
+import (
+	"embed"
+	"io"
+	"text/template"
+
+	"github.com/pkg/errors"
+)
+
+//go:embed config_template/*
+var configTemplate embed.FS
+
+// GenerateOPLConfig derives an Ory Permission Language config from the
+// namespaces and writes it to out. The OPL config is functionally equivalent to
+// the list of namespaces.
+func GenerateOPLConfig(namespaces []string, out io.Writer) error {
+	t, err := template.New("config_template").ParseFS(configTemplate, "config_template/*")
+	if err != nil {
+		return errors.WithStack(err)
+	}
+	return errors.WithStack(t.ExecuteTemplate(out,
+		"namespaces.ts.tmpl",
+		struct{ Namespaces []string }{Namespaces: namespaces}))
+}

cmd/namespace/opl_generate_test.go

@@ -0,0 +1,35 @@
+package namespace_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/ory/x/snapshotx"
+	"github.com/stretchr/testify/require"
+
+	"github.com/ory/keto/cmd/namespace"
+)
+
+func TestGenerateOPLConfig(t *testing.T) {
+	cases := []struct {
+		name       string
+		namespaces []string
+	}{{
+		name:       "empty",
+		namespaces: []string{},
+	}, {
+		name:       "one",
+		namespaces: []string{"one"},
+	}, {
+		name:       "many",
+		namespaces: []string{"one", "two", "three"},
+	}}
+
+	for _, tc := range cases {
+		t.Run("case="+tc.name, func(t *testing.T) {
+			var out bytes.Buffer
+			require.NoError(t, namespace.GenerateOPLConfig(tc.namespaces, &out))
+			snapshotx.SnapshotT(t, out.String())
+		})
+	}
+}