fix: use import attributes rather than json assertions

Author: lishaduck

packages/@contentlayer/core/src/generation/generate-dotpkg.ts

@@ -192,16 +192,16 @@ const writeFilesForCache = ({
         T.succeedWith(() => process.versions.node.split('.').map((_) => parseInt(_, 10)) as [number, number, number]),
       )
 
-      // NOTE Type assert statements for `.json` files are neccessary from Node v16.14 onwards
-      const needsJsonAssertStatement = nodeVersionMajor > 16 || (nodeVersionMajor === 16 && nodeVersionMinor >= 14)
-      const assertStatement = needsJsonAssertStatement ? ` assert { type: 'json' }` : ''
+      // NOTE: An import attribute for `.json` files is neccessary from Node v16.14 onwards.
+      const needsTypeJsonAttribute = nodeVersionMajor > 16 || (nodeVersionMajor === 16 && nodeVersionMinor >= 14)
+      const importAttributeStatement = needsJsonimportAttributeStatement ? ` with { type: 'json' }` : ''
 
       const typeNameField = generationOptions.options.fieldOptions.typeFieldName
       const dataBarrelFiles = documentDefs.map((docDef) => ({
         content: makeDataExportFile({
           docDef,
           documentIds: allDocuments.filter((_) => _[typeNameField] === docDef.name).map((_) => _._id),
-          assertStatement,
+          importAttributeStatement,
         }),
         filePath: withPrefix('generated', docDef.name, `_index.mjs`),
       }))
@@ -255,7 +255,7 @@ const writeFilesForCache = ({
             filePath: withPrefix('generated', 'index.mjs'),
             content: makeIndexMjs({
               schemaDef,
-              assertStatement,
+              importAttributeStatement,
               bundleFilePath: relativeBundleFilePath,
               isDev,
               options,
@@ -338,19 +338,19 @@ const writeFileWithWrittenFilesCache =
 const makeDataExportFile = ({
   docDef,
   documentIds,
-  assertStatement,
+  importAttributeStatement,
 }: {
   docDef: DocumentTypeDef
   documentIds: string[]
-  assertStatement: string
+  importAttributeStatement: string
 }): string => {
   const dataVariableName = getDataVariableName({ docDef })
 
   if (docDef.isSingleton) {
     const documentId = documentIds[0]!
     return `\
 // ${autogeneratedNote}
-export { default as ${dataVariableName} } from './${idToFileName(documentId)}.json'${assertStatement}
+export { default as ${dataVariableName} } from './${idToFileName(documentId)}.json'${importAttributeStatement}
 `
   }
 
@@ -376,7 +376,7 @@ export { default as ${dataVariableName} } from './${idToFileName(documentId)}.js
   )
 
   const docImports = documentIds
-    .map((_) => `import ${idToVariableNameMap.get(_)} from './${idToFileName(_)}.json'${assertStatement}`)
+    .map((_) => `import ${idToVariableNameMap.get(_)} from './${idToFileName(_)}.json'${importAttributeStatement}`)
     .join('\n')
 
   return `\
@@ -390,13 +390,13 @@ export const ${dataVariableName} = [${Array.from(idToVariableNameMap.values()).j
 
 const makeIndexMjs = ({
   schemaDef,
-  assertStatement,
+  importAttributeStatement,
   bundleFilePath,
   options,
   isDev,
 }: {
   schemaDef: SchemaDef
-  assertStatement: string
+  importAttributeStatement: string
   bundleFilePath: RelativePosixFilePath
   options: PluginOptions
   isDev: boolean
@@ -413,7 +413,7 @@ const makeIndexMjs = ({
     .map(({ documentDefName, dataVariableName }) =>
       isDev
         ? `import { ${dataVariableName} } from './${documentDefName}/_index.mjs'`
-        : `import ${dataVariableName} from './${documentDefName}/_index.json'${assertStatement}`,
+        : `import ${dataVariableName} from './${documentDefName}/_index.json'${importAttributeStatement}`,
     )
     .join('\n')
 
@@ -434,7 +434,7 @@ export const fetchContent = async (sourceKey) => {
   const worker = new Worker(workerFilePath, { workerData: { sourceKey } })
 
   return new Promise((resolve, reject) => {
-    worker.on('message', (data) => { 
+    worker.on('message', (data) => {
       if (data.result) {
         resolve(data.result)
       } else if (data.fatalError) {
@@ -485,7 +485,7 @@ export const makeDataTypes = ({ schemaDef, options }: { schemaDef: SchemaDef; op
     if (options.experimental.enableDynamicBuild === false) return ''
 
     return `\
-export type FetchContentResult = 
+export type FetchContentResult =
   | { _tag: 'Error', error: SourceProvideSchemaErrorJSON | SourceFetchDataErrorJSON }
   | { _tag: 'Data', data: DataExports }