New function TypeIDFromContext to get @id attribute from JSON-LD type (…

…#65)

merklize/merklize.go

@@ -162,6 +162,41 @@ func NewFieldPathFromContext(ctxBytes []byte, ctxType, fieldPath string) (Path,
 	return resPath, nil
 }
 
+// TypeIDFromContext returns @id attribute for type from JSON-LD context
+func TypeIDFromContext(ctxBytes []byte, typeName string) (string, error) {
+	var ctxObj map[string]interface{}
+	err := json.Unmarshal(ctxBytes, &ctxObj)
+	if err != nil {
+		return "", err
+	}
+
+	ldCtx, err := ld.NewContext(nil, nil).Parse(ctxObj["@context"])
+	if err != nil {
+		return "", err
+	}
+
+	typeDef := ldCtx.GetTermDefinition(typeName)
+
+	_, isType := typeDef["@context"]
+	if !isType {
+		return "", fmt.Errorf("looks like %v is not a type", typeName)
+	}
+
+	typeID, idFound := typeDef["@id"]
+	if !idFound {
+		return "", fmt.Errorf("@id attribute is not found for type %v",
+			typeName)
+	}
+
+	typeIDStr, ok := typeID.(string)
+	if !ok {
+		return "", fmt.Errorf("@id attribute is not a string for type %v",
+			typeName)
+	}
+
+	return typeIDStr, nil
+}
+
 // TypeFromContext returns type of field from context by path.
 func TypeFromContext(ctxBytes []byte, path string) (string, error) {
 	var ctxObj map[string]interface{}

merklize/merklize_test.go

@@ -1081,6 +1081,31 @@ func TestTypeFromContext(t *testing.T) {
 	require.Equal(t, "http://www.w3.org/2001/XMLSchema#integer", typ)
 }
 
+func TestTypeIDFromContext(t *testing.T) {
+	t.Run("url-like id", func(t *testing.T) {
+		ctxBytes, err := os.ReadFile("testdata/kyc_schema.json-ld")
+		require.NoError(t, err)
+
+		typeName := "KYCCountryOfResidenceCredential"
+		typeID, err := TypeIDFromContext(ctxBytes, typeName)
+		require.NoError(t, err)
+		require.Equal(t,
+			"https://raw.githubusercontent.com/iden3/claim-schema-vocab/main/schemas/json-ld/kyc-v4.json-ld#KYCCountryOfResidenceCredential",
+			typeID)
+	})
+
+	t.Run("urn-like id", func(t *testing.T) {
+		ctxBytes, err := os.ReadFile("testdata/kyc-v102.jsonld")
+		require.NoError(t, err)
+
+		typeName := "KYCCountryOfResidenceCredential"
+		typeID, err := TypeIDFromContext(ctxBytes, typeName)
+		require.NoError(t, err)
+		require.Equal(t, "urn:uuid:a81d4fae-7dec-11d0-a765-00a0c91e6bf0",
+			typeID)
+	})
+}
+
 func TestHashValues_FromDocument(t *testing.T) {
 	ctxBytes, err := os.ReadFile("testdata/kyc_schema.json-ld")
 	require.NoError(t, err)

merklize/testdata/kyc-v102.jsonld

@@ -0,0 +1,79 @@
+{
+  "@context": [
+    {
+      "@version": 1.1,
+      "@protected": true,
+      "id": "@id",
+      "type": "@type",
+      "KYCAgeCredential": {
+        "@id": "urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6",
+        "@context": {
+          "@version": 1.1,
+          "@protected": true,
+          "id": "@id",
+          "type": "@type",
+          "kyc-vocab": "https://github.com/iden3/claim-schema-vocab/blob/main/credentials/kyc.md#",
+          "xsd": "http://www.w3.org/2001/XMLSchema#",
+          "birthday": {
+            "@id": "kyc-vocab:birthday",
+            "@type": "xsd:integer"
+          },
+          "documentType": {
+            "@id": "kyc-vocab:documentType",
+            "@type": "xsd:integer"
+          }
+        }
+      },
+      "KYCCountryOfResidenceCredential": {
+        "@id": "urn:uuid:a81d4fae-7dec-11d0-a765-00a0c91e6bf0",
+        "@context": {
+          "@version": 1.1,
+          "@protected": true,
+          "id": "@id",
+          "type": "@type",
+          "kyc-vocab": "https://github.com/iden3/claim-schema-vocab/blob/main/credentials/kyc.md#",
+          "xsd": "http://www.w3.org/2001/XMLSchema#",
+          "countryCode": {
+            "@id": "kyc-vocab:countryCode",
+            "@type": "xsd:integer"
+          },
+          "documentType": {
+            "@id": "kyc-vocab:documentType",
+            "@type": "xsd:integer"
+          }
+        }
+      },
+      "KYCEmployee": {
+        "@id": "urn:uuid:b71d4fae-7dec-11d0-a765-00a0c91e6bf1",
+        "@context": {
+          "@version": 1.1,
+          "@protected": true,
+          "id": "@id",
+          "type": "@type",
+          "kyc-vocab": "https://github.com/iden3/claim-schema-vocab/blob/main/credentials/kyc.md#",
+          "xsd": "http://www.w3.org/2001/XMLSchema#",
+          "documentType": {
+            "@id": "kyc-vocab:documentType",
+            "@type": "xsd:integer"
+          },
+          "ZKPexperiance": {
+            "@id": "kyc-vocab:hasZKPexperiance",
+            "@type": "xsd:boolean"
+          },
+          "hireDate": {
+            "@id": "kyc-vocab:hireDate",
+            "@type": "xsd:dateTime"
+          },
+          "position": {
+            "@id": "kyc-vocab:position",
+            "@type": "xsd:string"
+          },
+          "salary": {
+            "@id": "kyc-vocab:salary",
+            "@type": "xsd:double"
+          }
+        }
+      }
+    }
+  ]
+}