Handler for action X Not Found Workflow Error

The following error may occur in production if you use a when-then block in your workflow:

custom-workflow:when-then-01JE8Z0M1FXSE2NCK1G04S0RR2:invoke - Handler for action \"when-then-01JE8Z0M1FXSE2NCK1G04S0RR2\" not found...

Why this Error Occurred#

This error occurs if the when-then block doesn't return a step's result and doesn't have a name specified.

For example:

when(input, (input) => !input.is_active)
  .then(() => {
    console.log("not returning anything")
  })

The above when-then block doesn't return a step's result, which causes the error.

How to Fix it#

You can resolve this error by passing a name as a first parameter of when:

const result = when(
    "custom-when-condition",
    input, 
    (input) => !input.is_active
  )
  .then(() => {
    console.log("not returning anything")
  })

Additional Resources#

• When-Then documentation