feat: utility to parse vertex properties and handle cardinality

gremlin-javascript/examples/browser/yarn.lock

@@ -729,14 +729,14 @@ __metadata:
 
 "gremlin@file:../../src/main/javascript/gremlin-javascript::locator=browser%40workspace%3A.":
   version: 4.0.0-alpha1
-  resolution: "gremlin@file:../../src/main/javascript/gremlin-javascript#../../src/main/javascript/gremlin-javascript::hash=83bc8e&locator=browser%40workspace%3A."
+  resolution: "gremlin@file:../../src/main/javascript/gremlin-javascript#../../src/main/javascript/gremlin-javascript::hash=fd5a82&locator=browser%40workspace%3A."
   dependencies:
     buffer: "npm:^6.0.3"
     eventemitter3: "npm:^5.0.1"
     readable-stream: "npm:^4.5.2"
     uuid: "npm:^9.0.1"
     ws: "npm:^8.16.0"
-  checksum: 10c0/13986e0b78a84a421e5542a7bb4ba8cca3fb7a12cb7fcce1426a40233f434a4ce86315aa943ce6818b101126a0167b8fa8e0a516dea0e98576fd68a22eef5650
+  checksum: 10c0/4ac483e068ae230130d3ca60718d3fac7031f00f2aba193f2bffffd444064281db5336ae55b16243d9427ff8ef60baad792c908ec3a41c21972f9dffcc85534f
   languageName: node
   linkType: hard
 

gremlin-javascript/src/main/javascript/gremlin-javascript/lib/index.ts

@@ -92,4 +92,5 @@ export const structure = {
   Vertex: graph.Vertex,
   VertexProperty: graph.VertexProperty,
   toLong: utils.toLong,
+  parseVertex: utils.parseVertex,
 };

gremlin-javascript/src/main/javascript/gremlin-javascript/lib/utils.ts

@@ -23,6 +23,7 @@
  */
 
 import * as uuid from 'uuid';
+import type { Vertex, VertexProperties } from './structure/graph.js';
 
 const gremlinVersion = '4.0.0-SNAPSHOT'; // DO NOT MODIFY - Configured automatically by Maven Replacer Plugin
 
@@ -119,3 +120,35 @@ export const DeferredPromise = <T>() => {
 
   return Object.assign(promise, { resolve, reject });
 };
+
+export const parseVertex = <
+  TVertex extends Vertex,
+  TCardinality extends { [P in keyof NonNullable<TVertex['properties']>]?: 'single' | 'list' | 'set' | undefined },
+>(
+  vertex: TVertex,
+  cardinality: TCardinality = {} as TCardinality,
+): {
+  [P in keyof NonNullable<TVertex['properties']>]: (typeof cardinality)[P] extends 'single'
+    ? NonNullable<TVertex['properties']>[P][0]['value']
+    : (typeof cardinality)[P] extends 'list'
+      ? Array<NonNullable<TVertex['properties']>[P][0]['value']>
+      : (typeof cardinality)[P] extends 'set'
+        ? Set<NonNullable<TVertex['properties']>[P][0]['value']>
+        : NonNullable<TVertex['properties']>[P][0]['value'];
+} =>
+  Object.fromEntries(
+    Object.entries<VertexProperties>(vertex.properties as any).map(([key, value]): any => [
+      key,
+      (() => {
+        switch (cardinality[key]) {
+          case 'list':
+            return value.map((x) => x.value);
+          case 'set':
+            return new Set(value.map((x) => x.value));
+          case 'single':
+          default:
+            return value[0].value;
+        }
+      })(),
+    ]),
+  ) as any;

gremlin-javascript/src/main/javascript/gremlin-javascript/package.json

@@ -33,6 +33,8 @@
     "@cucumber/cucumber": "^10.3.1",
     "@knighted/duel": "^1.0.7",
     "@tsconfig/node18": "^18.2.2",
+    "@types/chai": "^4.3.16",
+    "@types/mocha": "^10.0.6",
     "@types/readable-stream": "^4.0.10",
     "@types/uuid": "^9.0.8",
     "@types/ws": "^8.5.10",

gremlin-javascript/src/main/javascript/gremlin-javascript/test/unit/vertex-parser.ts

@@ -0,0 +1,60 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you under the Apache License, Version 2.0 (the
+ *  "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ */
+
+import { expect } from 'chai';
+import { describe, it } from 'mocha';
+import { Vertex, VertexProperties, VertexProperty } from '../../lib/structure/graph.js';
+import { parseVertex } from '../../lib/utils.js';
+
+describe('Vertex parser', () => {
+  it('should parse vertex properties with default cardinality', () => {
+    type PetVertex = Vertex<'pet', { name: VertexProperties<'name', string> }>;
+
+    const vertex: PetVertex = new Vertex(0, 'pet', {
+      name: [new VertexProperty(0, 'name', 'Pal')],
+    });
+
+    const parsedVertex = parseVertex(vertex);
+
+    expect(parsedVertex.name).to.equals('Fred');
+  });
+
+  it('should parse vertex properties with different cardinality', () => {
+    type PersonVertex = Vertex<
+      'person',
+      {
+        name: VertexProperties<'name', string>;
+        roles: VertexProperties<'role', string>;
+        weapons: VertexProperties<'weapon', string>;
+      }
+    >;
+
+    const vertex: PersonVertex = new Vertex(0, 'person', {
+      name: [new VertexProperty(0, 'name', 'Fred')],
+      roles: [new VertexProperty(0, 'role', 'hunter'), new VertexProperty(0, 'role', 'gatherer')],
+      weapons: [new VertexProperty(0, 'weapon', 'spear'), new VertexProperty(0, 'weapon', 'spear')],
+    });
+
+    const parsedVertex = parseVertex(vertex, { name: 'single', roles: 'set', weapons: 'list' });
+
+    expect(parsedVertex.name).to.equals('Fred');
+    expect(parsedVertex.roles).to.be.an.instanceOf(Set).to.have.all.keys(['hunter', 'gatherer']);
+    expect(parsedVertex.weapons).to.be.an.instanceOf(Array).to.includes.members(['spear', 'spear']);
+  });
+});