vu-error-boundary v0.0.4

This solution

This component provides a simple and reusable wrapper that you can use to wrap around your components. Any rendering errors in your components hierarchy can then be gracefully handled.

Table of Contents

• Installation
• Usage
• API
  • ErrorBoundary props
  • useErrorHandler(error?: Error)
• Issues
  • 🐛 Bugs
  • 💡 Feature Requests
• LICENSE

Installation

This module is distributed via npm which is bundled with node and should be installed as one of your project's dependencies:

$ npm i vu-error-boundary
# or
$ yarn add vu-error-boundary

Usage

The simplest way to use <ErrorBoundary> is to wrap it around any component that may throw an error. This will handle errors thrown by that component and its descendants too.

<script>
import {ErrorBoundary} from 'vu-error-boundary'
</script>

<template>
  <ErrorBoundary @reset="reset">
    <ComponentThatMayError />
    <template #fallback="{ resetErrorBoundary, error }">
      <div role="alert">
        <p>Something went wrong:</p>
        <pre>{{ error.message }}</pre>
        <button @click="resetErrorBoundary">Try again</button>
      </div>
    </template>
  </ErrorBoundary>
</template>

You can vue to errors (e.g. for logging) by providing an @error callback:

<script>
import {ErrorBoundary} from 'vu-error-boundary'

export default {
  setup() {
    const handleError = useErrorHandler()

    const myErrorHandler = (err: unknown, instance: ComponentPublicInstance | null, info: string) => {
      // Do something with the error
      // E.g. log to an error logging client here
    }

    return {
     myErrorHandler
    }
  },
}
</script>

<template>
  <ErrorBoundary @error="myErrorHandler">
    <ComponentThatMayError />
</template>

API

ErrorBoundary props

children

This is what you want rendered when everything's working fine. If there's an error that Vue can handle within the children of the ErrorBoundary, the ErrorBoundary will catch that and allow you to handle it gracefully.

FallbackComponent

This is a component you want rendered in the event of an error. As props it will be passed the error and resetErrorBoundary (which will reset the error boundary's state when called, useful for a "try again" button when used in combination with the onReset prop).

This is required if no fallback or fallbackRender prop is provided.

onError

This will be called when there's been an error that the ErrorBoundary has handled. It will be called with two arguments: error, info.

onReset

This will be called immediately before the ErrorBoundary resets it's internal state (which will result in rendering the children again). You should use this to ensure that re-rendering the children will not result in a repeat of the same error happening again.

onReset will be called with whatever resetErrorBoundary is called with.

Important: onReset will not be called when reset happens from a change in resetKeys. Use onResetKeysChange for that.

useErrorHandler(error?: Error)

Vue's onErrorCaptured feature is limited in that the boundaries can only handle errors thrown during Vue's lifecycles. To quote

Error boundaries do not catch errors for:

• Event handlers
• Asynchronous code (e.g. setTimeout or requestAnimationFrame callbacks)
• Server side rendering
• Errors thrown in the error boundary itself (rather than its children)

This means you have to handle those errors yourself, but you probably would like to reuse the error boundaries you worked hard on creating for those kinds of errors as well. This is what useErrorHandler is for.

There are two ways to use useErrorHandler:

1. const handleError = useErrorHandler(): call handleError(theError)
2. useErrorHandler(error): useful if you are managing the error state yourself or get it from another hook.

Here's an example:

<script>
export default {
  setup() {
    const handleError = useErrorHandler()

    function handleSubmit(event) {
      event.preventDefault()
      const name = event.target.elements.name.value
      fetchGreeting(name).then(
        newGreeting => setGreeting(newGreeting),
        handleError,
      )
    }

    return {
     handleSubmit
    }
  },
}
</script>

<template>
  <div v-if="greeting">{{greeting}}</div>
  <form v-else @submit="handleSubmit">
    <label>Name</label>
    <input id="name" />
    <button type="submit">get a greeting</button>
  </form>
</template>

Note, in case it's not clear what's happening here, you could also write handleSubmit like this:

function handleSubmit(event) {
  event.preventDefault()
  const name = event.target.elements.name.value
  fetchGreeting(name).then(
    newGreeting => setGreeting(newGreeting),
    error => handleError(error),
  )
}

Alternatively, let's say you're using a hook that gives you the error:

<script>
export default {
  setup() {
    const name = ref('')
    const {greeting, error} = useGreeting(name)
    useErrorHandler(error)

    function handleSubmit(event) {
      event.preventDefault()
      name.value = event.target.elements.name.value
    }

    return {
     handleSubmit
    }
  },
}
</script>

<template>
  <div v-if="greeting">{{greeting}}</div>
  <form v-else @submit="handleSubmit">
    <label>Name</label>
    <input id="name" />
    <button type="submit">get a greeting</button>
  </form>
</template>

In this case, if the error is ever set to a truthy value, then it will be propagated to the nearest error boundary.

In either case, you could handle those errors like this:

<template>
   <ErrorBoundary>
    <Greeting />
    <template #fallback="{ resetErrorBoundary, error }">
     ...
  </ErrorBoundary>
</template>

And now that'll handle your runtime errors as well as the async errors in the fetchGreeting or useGreeting code.

Issues

Looking to contribute? Look for the Good First Issue label.

🐛 Bugs

Please file an issue for bugs, missing documentation, or unexpected behavior.

See Bugs

💡 Feature Requests

Please file an issue to suggest new features. Vote on feature requests by adding a 👍. This helps maintainers prioritize what to work on.

See Feature Requests

LICENSE

MIT