feat: support computed relations in graph (#309)

Author: miparnisari

pkg/go/graph/graph_builder.go

@@ -63,6 +63,10 @@ func parseModel(model *openfgav1.AuthorizationModel) (*multi.DirectedGraph, erro
 			if _, ok := rewrite.GetUserset().(*openfgav1.Userset_This); ok {
 				parseThis(typeDef, relation, graphBuilder, relationNode)
 			}
+
+			if _, ok := rewrite.GetUserset().(*openfgav1.Userset_ComputedUserset); ok {
+				parseComputed(rewrite, typeDef.GetType(), graphBuilder, relationNode)
+			}
 		}
 	}
 
@@ -104,6 +108,15 @@ func parseThis(typeDef *openfgav1.TypeDefinition, relation string, graphBuilder
 	}
 }
 
+func parseComputed(rewrite *openfgav1.Userset, typeName string, graphBuilder *AuthorizationModelGraphBuilder, relationNode *AuthorizationModelNode) {
+	// e.g. define x: y. Here y is the rewritten relation
+	rewrittenRelation := rewrite.GetComputedUserset().GetRelation()
+	rewrittenNodeName := fmt.Sprintf("%s#%s", typeName, rewrittenRelation)
+	newNode := graphBuilder.GetOrAddNode(rewrittenNodeName, rewrittenNodeName, SpecificTypeAndRelation)
+	// new edge from y to x
+	graphBuilder.AddEdge(newNode, relationNode, ComputedEdge)
+}
+
 func (g *AuthorizationModelGraphBuilder) GetOrAddNode(uniqueLabel, label string, nodeType NodeType) *AuthorizationModelNode {
 	if existingNode := g.GetNodeFor(uniqueLabel); existingNode != nil {
 		return existingNode

pkg/go/graph/graph_builder_test.go

@@ -139,6 +139,57 @@ rankdir=BT
 
 // Edge definitions.
 2 -> 1 [label=direct];
+}`,
+		},
+		`computed_relation`: {
+			model: `
+				model
+					schema 1.1
+				type folder
+					relations
+						define x: y
+						define y: [user]
+				type user`,
+			expectedOutput: `digraph {
+graph [
+rankdir=BT
+];
+
+// Node definitions.
+0 [label=folder];
+1 [label="folder#x"];
+2 [label="folder#y"];
+3 [label=user];
+
+// Edge definitions.
+2 -> 1 [style=dashed];
+3 -> 2 [label=direct];
+}`,
+		},
+		`computed_relation_with_cycle`: {
+			model: `
+				model
+					schema 1.1
+				type folder
+					relations
+						define x: y
+						define y: z
+						define z: x`,
+			expectedOutput: `digraph {
+graph [
+rankdir=BT
+];
+
+// Node definitions.
+0 [label=folder];
+1 [label="folder#x"];
+2 [label="folder#y"];
+3 [label="folder#z"];
+
+// Edge definitions.
+1 -> 3 [style=dashed];
+2 -> 1 [style=dashed];
+3 -> 2 [style=dashed];
 }`,
 		},
 	}
@@ -159,7 +210,7 @@ rankdir=BT
 
 			diff := cmp.Diff(expectedSorted, actualSorted)
 
-			require.Empty(t, diff, "expected %s\ngot %s", test.expectedOutput, actualDOT)
+			require.Empty(t, diff, "expected %s\ngot\n%s", test.expectedOutput, actualDOT)
 		})
 	}
 }

pkg/go/graph/graph_edge.go

@@ -8,7 +8,8 @@ import (
 type EdgeType int64
 
 const (
-	DirectEdge EdgeType = 0 // e.g. `group`
+	DirectEdge   EdgeType = 0
+	ComputedEdge EdgeType = 1
 )
 
 type AuthorizationModelEdge struct {
@@ -30,5 +31,12 @@ func (n *AuthorizationModelEdge) Attributes() []encoding.Attribute {
 		})
 	}
 
+	if n.edgeType == ComputedEdge {
+		attrs = append(attrs, encoding.Attribute{
+			Key:   "style",
+			Value: "dashed",
+		})
+	}
+
 	return attrs
 }