ianstormtaylor/slate · error · Error

Properties specified for a hyperscript shorthand should be a

Error message

Properties specified for a hyperscript shorthand should be an object, but for the custom element <${tagName}>  tag you passed: ${props}

What it means

Thrown by normalizeElements in createHyperscript when a custom element shorthand maps a tag name to a non-object value. Each entry of the elements option must be a props object merged into the created element.

Source

Thrown at packages/slate-hyperscript/src/hyperscript.ts:114

    const ret = creator(tagName, attributes, children)
    return ret
  }

  return jsx
}

/**
 * Normalize a dictionary of element shorthands into creator functions.
 */

const normalizeElements = (elements: HyperscriptShorthands) => {
  const creators: HyperscriptCreators<Element> = {}

  for (const tagName in elements) {
    const props = elements[tagName]

    if (typeof props !== 'object') {
      throw new Error(
        `Properties specified for a hyperscript shorthand should be an object, but for the custom element <${tagName}>  tag you passed: ${props}`
      )
    }

    creators[tagName] = (
      tagName: string,
      attributes: { [key: string]: any },
      children: any[]
    ) => {
      return createElement('element', { ...props, ...attributes }, children)
    }
  }

  return creators
}

export { createHyperscript, HyperscriptCreators, HyperscriptShorthands }

View on GitHub (pinned to 72a37c701e)

Solutions

1. Change every elements entry to a plain object of props, e.g. { type: 'paragraph' }
2. If you need full control, provide a creator function via creators instead of elements
3. Verify no entry is null/undefined/string/number before creating the hyperscript

Example fix

// before
const jsx = createHyperscript({ elements: { block: 'paragraph' } })
// after
const jsx = createHyperscript({ elements: { block: { type: 'paragraph' } } })

for (const [tag, props] of Object.entries(elements)) {
  if (typeof props !== 'object' || props === null || Array.isArray(props)) {
    throw new Error(`elements.${tag} must be a props object, got ${typeof props}`)
  }
}

const isElementProps = (p: unknown): p is Record<string, unknown> =>
  typeof p === 'object' && p !== null && !Array.isArray(p)

null

When it happens

Trigger: Passing elements: { block: 'paragraph' } (a string) or elements: { block: null / 42 } to createHyperscript instead of elements: { block: { type: 'paragraph' } }.

Common situations: Confusing the elements shorthand format (assuming a string type is accepted); copy-pasting config from older hyperscript examples; passing arrays or undefined values.

Related errors

• Unexpected hyperscript child object: ${child}
• The <selection> hyperscript tag must have an <anchor> tag as
• The <selection> hyperscript tag must have a <focus> tag as a
• The <text> hyperscript tag must only contain a single node's
• The <text> hyperscript tag can only contain text conten

AI-assisted analysis of ianstormtaylor/slate@72a37c701e (2026-08-27). Data as JSON: /api/errors/f5265d2cda18e19e. Report an issue: GitHub.