Suspense Has No Built-in Error Handling

Rule

<Suspense> does not provide error handling via the component itself. You must implement error handling using errorCaptured option or onErrorCaptured() hook in a parent component to catch async errors.

Why This Matters

Without explicit error handling, async errors in suspended components will propagate uncaught, potentially crashing the application or leaving users stuck on loading states. Unlike React's Error Boundaries, Vue's Suspense requires manual error boundary implementation.

Bad Code

<script setup>
// No error handling - async errors will propagate uncaught
</script>

<template>
  <Suspense>
    <AsyncComponent />
    <template #fallback>
      Loading...
    </template>
  </Suspense>
</template>

Good Code

<script setup>
import { ref, onErrorCaptured } from 'vue'
import AsyncComponent from './AsyncComponent.vue'

const error = ref(null)

onErrorCaptured((err) => {
  error.value = err
  return false // Prevent error from propagating further
})
</script>

<template>
  <div v-if="error" class="error-state">
    <p>Something went wrong: {{ error.message }}</p>
    <button @click="error = null">Retry</button>
  </div>

  <Suspense v-else>
    <AsyncComponent />
    <template #fallback>
      Loading...
    </template>
  </Suspense>
</template>

Reusable Error Boundary Pattern

<!-- ErrorBoundary.vue -->
<script setup>
import { ref, onErrorCaptured } from 'vue'

const props = defineProps({
  fallback: {
    type: String,
    default: 'Something went wrong'
  }
})

const emit = defineEmits(['error'])

const error = ref(null)

onErrorCaptured((err, instance, info) => {
  error.value = { err, instance, info }
  emit('error', { err, instance, info })
  return false
})

const reset = () => {
  error.value = null
}

defineExpose({ reset })
</script>

<template>
  <slot v-if="!error" />
  <slot v-else name="error" :error="error" :reset="reset">
    <div class="error-boundary">
      {{ fallback }}
      <button @click="reset">Retry</button>
    </div>
  </slot>
</template>

<!-- Usage -->
<template>
  <ErrorBoundary @error="logError">
    <Suspense>
      <AsyncDashboard />
      <template #fallback>Loading dashboard...</template>
    </Suspense>

    <template #error="{ error, reset }">
      <DashboardError :error="error" @retry="reset" />
    </template>
  </ErrorBoundary>
</template>

Key Points

1. Always wrap <Suspense> with error handling logic in production
2. Use onErrorCaptured for Composition API or errorCaptured option for Options API
3. Return false from the error handler to stop propagation
4. Consider creating a reusable ErrorBoundary component to reduce boilerplate
5. Provide a way for users to retry failed operations

References

• Vue.js Suspense Documentation
• Vue.js onErrorCaptured