Can't query data from contentful to gatsby project - graphql

Question

Don't get the query to contentful to work.
Receive error message:
TypeError: Cannot read property 'allContentfulMagArticle' of undefined
datais undefined inside the Posts component. Can't see what i'm doing wrong here.
import { graphql } from 'gatsby';
import Post from "./post.js";
import './posts.css';
export const query = graphql`
query {
allContentfulMagArticle{
edges{
node{
index
title
name
subHeading
extract {
raw
}
slug
}
}
}
}
`
const Posts = ({ data }) => {
return (
<section className="posts">
<ul className="post-list">
{data.allContentfulMagArticle.edges.map(({ node }) => (
<Post
key={node.index}
id={node.index}
node={node}
title={node.title}
name={node.name}
// image={node.frontmatter.featuredImage.childImageSharp.fluid}
subheading={node.subheading}
body={node.extract.raw}
/>
))}
</ul>
</section>
)
}
export default Posts
Here my gatsby-config.js:
require('dotenv').config({
path: `.env`,
})
module.exports = {
siteMetadata: {
title: `XX`,
description: `XX`,
author: `Lisa Lee`,
url: `https://www.tortmagazine.com`
},
plugins: [
`gatsby-plugin-react-helmet`,
'gatsby-plugin-fontawesome-css',
'gatsby-plugin-sharp',
`gatsby-transformer-sharp`,
`gatsby-transformer-remark`,
{
resolve: `gatsby-source-filesystem`,
options: {
path: `${__dirname}/src/`,
},
},
{
resolve: `gatsby-source-contentful`,
options: {
spaceId: process.env.GATSBY_CONTENTFUL_SPACE_ID,
accessToken: process.env.GATSBY_CONTENTFUL_ACCESS_TOKEN,
},
},
],
}

Answer 1

You used the word "component" to describe your Posts but the query you are using only works in a page, or in the context of createPage (so in a template file as well). If you are indeed in a component, that will be the issue. If not, then I'm not clear what is wrong, I use the same pattern (eg: data.edges.node.map()) and it works for me.
The only other difference I noticed is in gatsby-config, I define an environment key. I'm not sure what the behavior is if none is defined, probably defaults to master so you may also want to confirm you're on the right environment.