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Vue 3 debugging and error handling for runtime errors, warnings, async failures, and SSR/hydration issues. Use when diagnosing or fixing Vue issues.

Use this Skill: https://skilld.dev/gh/vuejs-ai/skills/vue-debug-guides

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referenceselect-initial-value-ios-bug.md

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Select Element iOS Bug - Always Include Disabled Placeholder Option

Impact: HIGH - When a <select> element's v-model initial value doesn't match any option, iOS renders it as "unselected" and users CANNOT select the first item. iOS doesn't fire a change event when selecting an already-visually-selected option, leaving users stuck.

This is a platform-specific bug that only manifests on iOS Safari. Desktop browsers and Android handle this gracefully, making it easy to miss during development. The fix is simple: always include a disabled placeholder option.

Task Checklist

  • Always add a disabled placeholder option with empty value to select elements
  • Ensure v-model initial value is empty string to match the placeholder
  • Test select inputs on iOS devices or simulators
  • Consider this for any user-facing forms, especially on mobile-first apps

Problem - iOS users cannot select first option:

<script setup>
import { ref } from 'vue'

// Initial value is empty string, doesn't match any option
const selected = ref('')
</script>

<template>
  <!-- PROBLEM: On iOS, "Apple" appears selected but user cannot actually select it -->
  <!-- Tapping "Apple" does nothing because iOS doesn't fire change event -->
  <select v-model="selected">
    <option value="apple">Apple</option>
    <option value="banana">Banana</option>
    <option value="orange">Orange</option>
  </select>

  <!-- selected remains '' even though "Apple" appears highlighted -->
</template>

Solution - Add disabled placeholder option:

<script setup>
import { ref } from 'vue'

const selected = ref('')  // Matches the placeholder option
</script>

<template>
  <!-- CORRECT: Disabled placeholder ensures user must actively select -->
  <select v-model="selected">
    <option disabled value="">Please select a fruit</option>
    <option value="apple">Apple</option>
    <option value="banana">Banana</option>
    <option value="orange">Orange</option>
  </select>
</template>
<!-- Variant with required attribute for form validation -->
<select v-model="selected" required>
  <option disabled value="">-- Select an option --</option>
  <option value="a">Option A</option>
  <option value="b">Option B</option>
</select>
<!-- If you MUST have a pre-selected default, set the initial value to match -->
<script setup>
import { ref } from 'vue'

// Set initial value to match an actual option
const country = ref('us')  // Pre-selects "United States"
</script>

<template>
  <select v-model="country">
    <option value="us">United States</option>
    <option value="uk">United Kingdom</option>
    <option value="ca">Canada</option>
  </select>
</template>

Reference

Source: SKILL.md on GitHub

1 warning17d5 checks · Risk SAFE
  • Gen Agent Trust Hub17d

    This skill is a comprehensive collection of educational debugging guides and best practices for Vue 3 developers. It contains no executable code or malicious instructions and focuses solely on diagnosing common runtime errors and performance issues.

  • Socket17d

    No alerts

  • Snyk17d

    Risk: LOW · No issues

  • Runlayer7mo

    140/140 files flagged

  • ZeroLeaks5mo

    Score: 93/100 · 2 sections analyzed

Signed by skilld at a5fc891. This ties the file your Agent reads to that commit on GitHub. It does not review the instructions.

Last checked against GitHub 2 months ago.

Steadyupdated 8 months ago

README badge

README badge for vuejs-ai/skills/vue-debug-guides

Guides for diagnosing Vue 3 runtime errors, reactivity bugs, component lifecycle issues, and SSR hydration problems. Covers reactivity traps (refs, computed, watchers), component mechanics (props, emits, slots), templates (v-if, v-for, refs), forms (v-model), and composition API gotchas.

Generated from the current SKILL.md.

Does this cover Vue 2 or only Vue 3?
This skill is for Vue 3 only. It addresses Vue 3-specific debugging patterns like reactivity proxies, script setup, and defineEmits/defineProps.
Does this skill help with performance optimization?
No. This skill focuses on runtime errors, warnings, and behavioral bugs. For development best practices and optimization, use the separate `vue-best-practices` skill.
What kinds of issues does this cover?
Reactivity traps (refs, computed, watchers), component lifecycle bugs, template directives, form binding edge cases, SSR/hydration mismatches, slot scoping, and async-related failures.
Does this include debugging for Nuxt or other Vue frameworks?
No. This skill focuses on core Vue 3 runtime issues. Framework-specific bugs are outside its scope.

Generated from the current SKILL.md. These answers refresh after source changes.