f5792c40be
Pulled ALL skills from 15 source repositories: - anthropics/skills: 16 (docs, design, MCP, testing) - obra/superpowers: 14 (TDD, debugging, agents, planning) - coreyhaines31/marketingskills: 25 (marketing, CRO, SEO, growth) - better-auth/skills: 5 (auth patterns) - vercel-labs/agent-skills: 5 (React, design, Vercel) - antfu/skills: 16 (Vue, Vite, Vitest, pnpm, Turborepo) - Plus 13 individual skills from various repos Mosaic Stack is not limited to coding — the Orchestrator and subagents serve coding, business, design, marketing, writing, logistics, analysis, and more. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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1.8 KiB
title, impact, impactDescription, tags
| title | impact | impactDescription | tags |
|---|---|---|---|
| Never Use && with Potentially Falsy Values | CRITICAL | prevents production crash | rendering, conditional, jsx, crash |
Never Use && with Potentially Falsy Values
Never use {value && <Component />} when value could be an empty string or
0. These are falsy but JSX-renderable—React Native will try to render them as
text outside a <Text> component, causing a hard crash in production.
Incorrect (crashes if count is 0 or name is ""):
function Profile({ name, count }: { name: string; count: number }) {
return (
<View>
{name && <Text>{name}</Text>}
{count && <Text>{count} items</Text>}
</View>
)
}
// If name="" or count=0, renders the falsy value → crash
Correct (ternary with null):
function Profile({ name, count }: { name: string; count: number }) {
return (
<View>
{name ? <Text>{name}</Text> : null}
{count ? <Text>{count} items</Text> : null}
</View>
)
}
Correct (explicit boolean coercion):
function Profile({ name, count }: { name: string; count: number }) {
return (
<View>
{!!name && <Text>{name}</Text>}
{!!count && <Text>{count} items</Text>}
</View>
)
}
Best (early return):
function Profile({ name, count }: { name: string; count: number }) {
if (!name) return null
return (
<View>
<Text>{name}</Text>
{count > 0 ? <Text>{count} items</Text> : null}
</View>
)
}
Early returns are clearest. When using conditionals inline, prefer ternary or explicit boolean checks.
Lint rule: Enable react/jsx-no-leaked-render from
eslint-plugin-react
to catch this automatically.