Subchapter 1.6

Architecture Avoid Boolean Props

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Avoid Boolean Prop Proliferation

Don’t add boolean props like isThread, isEditing, isDMThread to customize component behavior. Each boolean doubles possible states and creates unmaintainable conditional logic. Use composition instead.

Architecture Avoid Boolean Props · Vercel Composition Patterns · vercel-labs/agent-skills · Skills Docs

function Composer({
  onSubmit,
  isThread,
  channelId,
  isDMThread,
  dmId,
  isEditing,
  isForwarding,
}: Props) {
  return (
    <form>
      <Header />
      <Input />
      {isDMThread ? (
        <AlsoSendToDMField id={dmId} />
      ) : isThread ? (
        <AlsoSendToChannelField id={channelId} />
      ) : null}
      {isEditing ? (
        <EditActions />
      ) : isForwarding ? (
        <ForwardActions />
      ) : (
        <DefaultActions />
      )}
      <Footer onSubmit={onSubmit} />
    </form>
  )
}

// Channel composer
function ChannelComposer() {
  return (
    <Composer.Frame>
      <Composer.Header />
      <Composer.Input />
      <Composer.Footer>
        <Composer.Attachments />
        <Composer.Formatting />
        <Composer.Emojis />
        <Composer.Submit />
      </Composer.Footer>
    </Composer.Frame>
  )
}

// Thread composer - adds "also send to channel" field
function ThreadComposer({ channelId }: { channelId: string }) {
  return (
    <Composer.Frame>
      <Composer.Header />
      <Composer.Input />
      <AlsoSendToChannelField id={channelId} />
      <Composer.Footer>
        <Composer.Formatting />
        <Composer.Emojis />
        <Composer.Submit />
      </Composer.Footer>
    </Composer.Frame>
  )
}

// Edit composer - different footer actions
function EditComposer() {
  return (
    <Composer.Frame>
      <Composer.Input />
      <Composer.Footer>
        <Composer.Formatting />
        <Composer.Emojis />
        <Composer.CancelEdit />
        <Composer.SaveEdit />
      </Composer.Footer>
    </Composer.Frame>
  )
}