Question

我正在尝试实现以下教程中描述的GrapgQL API。

GraphQL API using Serverless + AWS AppSync + DynamoDB + Lambda resolvers + Cognito. [Part 1]

我正在使用最新版本的无服务器和其他涉及的依赖项。（请参阅package.json）我的操作系统是Manjaro 5.4.2-1。

我的问题是common-response.vtl无法离线。部署到AWS后一切正常。

* file: mapping-templates/common-response.vtl *
## If there is a datasource invocation error, we choose to raise the same error
## the field data will be set to null.
#if($ctx.error)
  $util.error($ctx.error.message, $ctx.error.type, $ctx.result)
#end

$util.toJson($ctx.result)

* file: lambda-functions/book/listBooks/index.js *
exports.handler = async (event) => {
  console.log({event});

  const books = [
    {
      id: '1',
      title: 'First mocked book'
    },
    {
      id: '2',
      title: 'Second mocked book'
    }
  ];
  console.log(books);
  return books;
};

lambda解析器日志看起来不错

* console *
Serverless: dynamoDB started: http://localhost:62226/
listening for subscriptions at: ws://localhost:38643/
Serverless: AppSync started: http://localhost:62222/graphql
Serverless: Starting Offline: local/eu-west-1.

Serverless: Routes for listBooks:
Serverless: POST /{apiVersion}/functions/sls-appsync-demo-local-listBooks/invocations

Serverless: Offline [HTTP] listening on http://localhost:3001
Serverless: Enter "rp" to replay the last request
{ event: { arguments: {} } }
[
  { id: '1', title: 'First mocked book' },
  { id: '2', title: 'Second mocked book' }
]
{ event: { arguments: {} } }
[
  { id: '1', title: 'First mocked book' },
  { id: '2', title: 'Second mocked book' }
]

但是邮递员的回复是一个错误

* postman *
{
    "errors": [
        {
            "message": "JSON5: invalid character '&' at 2:3",
            "locations": [
                {
                    "line": 2,
                    "column": 3
                }
            ],
            "path": [
                "listBooks"
            ]
        }
    ],
    "data": {
        "listBooks": null
    }
}

当我将记录的响应粘贴到解析器中时，邮递员会打印出预期的结果。我还尝试将结果放入错误响应中。

* file: mapping-templates/common-response.vtl *
## If there is a datasource invocation error, we choose to raise the same error
## the field data will be set to null.
#if($ctx.error)
  $util.error($ctx.error.message, $ctx.error.type, $ctx.result)
#end

$util.error($ctx.result)

结果在那里...

* postman *
{
    "data": {
        "listBooks": null
    },
    "errors": [
        {
            "message": [
                {
                    "id": "1",
                    "title": "First mocked book"
                },
                {
                    "id": "2",
                    "title": "Second mocked book"
                }
            ],
            "locations": [
                {
                    "line": 2,
                    "column": 3
                }
            ],
            "path": [
                "listBooks"
            ],
            "errorType": null,
            "data": null,
            "errorInfo": null
        }
    ]
}

因此toJson函数与脱机appsync结合使用时出现问题，但我不知道如何解决此问题

完整的示例代码：github repo

AppSync离线-“ JSON5：无效字符'＆'在2：3处”

0 个答案: