fix(gatsby-source-contentful): fix structured content fields

[macklinu]

This PR fixes an issue with gatsby-source-contentful where the internal prepareStructuredTextNode() was trying to call an undefined function.

You can see here that the function defines 5 expected arguments:

gatsby/packages/gatsby-source-contentful/src/normalize.js

Lines 196 to 221 in 19f3d5a

	function prepareStructuredTextNode(
	node,
	key,
	content,
	createNode,
	createNodeId
	) {
	const str = JSON.stringify(content)
	const structuredTextNode = {
	...content,
	id: createNodeId(`${node.id}${key}RichTextNode`),
	parent: node.id,
	children: [],
	[key]: str,
	internal: {
	type: _.camelCase(`${node.internal.type} ${key} RichTextNode`),
	mediaType: `text/richtext`,
	content: str,
	contentDigest: digest(str),
	},
	}
	node.children = node.children.concat([structuredTextNode.id])
	return structuredTextNode
	}

The 4th argument is createNode (which is unused). And the only usage I could find of this function receives 4 arguments (with createNodeId being the last argument):

gatsby/packages/gatsby-source-contentful/src/normalize.js

Lines 415 to 420 in 19f3d5a

	const richTextNode = prepareStructuredTextNode(
	entryNode,
	entryItemFieldKey,
	entryItemFields[entryItemFieldKey],
	createNodeId
	)

[macklinu]

I'm working with Rich Text nodes in a Contentful space, and there isn't a unit test for this currently that I can tell in the normalize.js file, so I'm testing changes locally now. Will push up another commit or comment if something isn't working with this PR.

[macklinu]

Confirmed by modifying the gatsby-source-contentful package in my project's node_modules directory by removing the createNode argument, and I am now seeing my rich text models in the GraphQL inspector after running gatsby develop. 👍

[pieh]

Oh yeah! Thanks for the fix @macklinu!