File size: 2,062 Bytes
1e92f2d |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 |
import { defineRule } from '../utils/define-rule'
const url = 'https://nextjs.org/docs/messages/no-duplicate-head'
export = defineRule({
meta: {
docs: {
description:
'Prevent duplicate usage of `<Head>` in `pages/_document.js`.',
recommended: true,
url,
},
type: 'problem',
schema: [],
},
create(context) {
const { sourceCode } = context
let documentImportName
return {
ImportDeclaration(node) {
if (node.source.value === 'next/document') {
const documentImport = node.specifiers.find(
({ type }) => type === 'ImportDefaultSpecifier'
)
if (documentImport && documentImport.local) {
documentImportName = documentImport.local.name
}
}
},
ReturnStatement(node) {
const ancestors = sourceCode.getAncestors(node)
const documentClass = ancestors.find(
(ancestorNode) =>
ancestorNode.type === 'ClassDeclaration' &&
ancestorNode.superClass &&
'name' in ancestorNode.superClass &&
ancestorNode.superClass.name === documentImportName
)
if (!documentClass) {
return
}
if (
node.argument &&
'children' in node.argument &&
node.argument.children
) {
// @ts-expect-error - `node.argument` could be a `JSXElement` which has property `children`
const headComponents = node.argument.children.filter(
(childrenNode) =>
childrenNode.openingElement &&
childrenNode.openingElement.name &&
childrenNode.openingElement.name.name === 'Head'
)
if (headComponents.length > 1) {
for (let i = 1; i < headComponents.length; i++) {
context.report({
node: headComponents[i],
message: `Do not include multiple instances of \`<Head/>\`. See: ${url}`,
})
}
}
}
},
}
},
})
|