Using Meteor.wrapAsync correctly

help
1

Hopefully this is a newbie question.
I have the following code that I am trying to convert to using meteor.wrapAsync. I am getting a “Exception while invoking method ‘emailSend’ ReferenceError: syncfunc is not defined” exception. What am i missing?

stacktrace:

I20191031-06:21:16.246(-5)? Exception while invoking method 'emailSend' ReferenceError: syncfunc is not defined
I20191031-06:21:16.248(-5)?     at MethodInvocation.emailSend (src/imports/api/email.js:13:27)
I20191031-06:21:16.249(-5)?     at maybeAuditArgumentChecks (packages/ddp-server/livedata_server.js:1771:12)
I20191031-06:21:16.273(-5)?     at DDP._CurrentMethodInvocation.withValue (packages/ddp-server/livedata_server.js:719:19)  
I20191031-06:21:16.275(-5)?     at Meteor.EnvironmentVariable.EVp.withValue (packages\meteor.js:1234:12)
I20191031-06:21:16.276(-5)?     at DDPServer._CurrentWriteFence.withValue (packages/ddp-server/livedata_server.js:717:46)  
I20191031-06:21:16.277(-5)?     at Meteor.EnvironmentVariable.EVp.withValue (packages\meteor.js:1234:12)
I20191031-06:21:16.277(-5)?     at Promise (packages/ddp-server/livedata_server.js:715:46)
I20191031-06:21:16.278(-5)?     at new Promise (<anonymous>)
I20191031-06:21:16.279(-5)?     at Session.method (packages/ddp-server/livedata_server.js:689:23)
I20191031-06:21:16.280(-5)?     at packages/ddp-server/livedata_server.js:559:43

email.js:

Meteor.methods(
{
  emailSend(fromAddress, subject, emailText) 
  {
    if (Meteor.isServer) 
    {     
      const { Email } = require('../server/email.js');
      var syncFunc = Meteor.wrapAsync(Email.send); 
      var sendEmailReturn=syncfunc(fromAddress, subject, emailText);      
      return sendEmailReturn;
      **//if I comment out the above three lines and uncomment the line below then the application works fine.** 
      //return Email.send(fromAddress, subject, emailText);      
    }
  },  
})
2

You declare this as syncFunc, but use it as syncfunc.

Additionally, it’s often necessary to ensure the scope of the wrapped function is also set in the wrapAsync. I would rewrite your code to something like:

Meteor.methods(
  {
    emailSend(fromAddress, subject, emailText) {
      if (Meteor.isServer) {
        const { Email } = require('../server/email.js');
        const syncFunc = Meteor.wrapAsync(Email.send, Email);
        const sendEmailReturn = syncFunc(fromAddress, subject, emailText);
        return sendEmailReturn;
      }
    },
  });
1 Like
3

Thank you @robfallows. I need to drink some coffee before I post questions. :frowning:

1 Like
4

The best way to use Meteor.wrapAsync is to not use it and instead manage with Promises ahah !

===> I’m leaving already

2 Likes
5

Does Email.send have the right signature? I always thought it just ran synchronously (in a Fiber), and didn’t return anything. The docs aren’t perfectly clear…

6

Yes Meteor’s Email.send is synchronous, but in this case Email comes from user code, so it’s likely not the version given by Meteor: