fix: resolve _app deps in API routes

Author: ascorbic

package-lock.json

@@ -49,9 +49,13 @@ export const generateFunctions = async (
       join(__dirname, '..', '..', 'lib', 'templates', 'handlerUtils.js'),
       join(functionsDir, functionName, 'handlerUtils.js'),
     )
+
+    const resolveSourceFile = (file: string) => join(publish, 'server', file)
+
     const resolverSource = await getSinglePageResolver({
       functionsDir,
-      sourceFile: join(publish, 'server', compiled),
+      // These extra pages are always included by Next.js
+      sourceFiles: [compiled, 'pages/_app.js', 'pages/_document.js', 'pages/_error.js'].map(resolveSourceFile),
     })
     await writeFile(join(functionsDir, functionName, 'pages.js'), resolverSource)
   }

packages/runtime/src/helpers/functions.ts

@@ -39,16 +39,18 @@ export const getPageResolver = async ({ publish, target }: { publish: string; ta
  */
 export const getSinglePageResolver = async ({
   functionsDir,
-  sourceFile,
+  sourceFiles,
 }: {
   functionsDir: string
-  sourceFile: string
+  sourceFiles: Array<string>
 }) => {
-  const dependencies = await getDependenciesOfFile(sourceFile)
+  const dependencies = await Promise.all(sourceFiles.map((sourceFile) => getDependenciesOfFile(sourceFile)))
   // We don't need the actual name, just the relative path.
   const functionDir = resolve(functionsDir, 'functionName')
 
-  const pageFiles = [sourceFile, ...dependencies]
+  const deduped = [...new Set(dependencies.flat())]
+
+  const pageFiles = [...sourceFiles, ...deduped]
     .map((file) => `require.resolve('${relative(functionDir, file)}')`)
     .sort()