import { graphql , useStaticQuery } from 'gatsby' ; import React from 'react' ; import Helmet from 'react-helmet' ; /**
 * SEO component that queries for data with
 *  Gatsby's useStaticQuery React hook
 *
 * See: https://www.gatsbyjs.org/docs/use-static-query/
 */ type Props = { title : string ; keywords : string [ ] ; description ? : string ; lang ? : string ; meta ? : { name : string ; content : string ; } [ ] ; } ; function SEO ( { description , lang = 'en' , meta = [ ] , keywords = [ ] , title } ) { const { site } = useStaticQuery ( graphql `
      query {
        site {
          siteMetadata {
            title
            description
            author
          }
        }
      }
    ` ) ; const metaDescription = description || site . siteMetadata . description ; return ( < Helmet htmlAttributes = { { lang } } title = { title } titleTemplate = { title } meta = { [ { name : `description` , content : metaDescription } , { property : `og:title` , content : title } , { property : `og:description` , content : metaDescription } , { property : `og:type` , content : `website` } , { name : `twitter:card` , content : `summary` } , { name : `twitter:creator` , content : site . siteMetadata . author } , { name : `twitter:title` , content : title } , { name : `twitter:description` , content : metaDescription } , ] . concat ( keywords . length > 0 ? { name : `keywords` , content : keywords . join ( `, ` ) } : [ ] ) . concat ( meta ) } / > ) ; } export default SEO ;