fix: require index.js or index.ts as entrypoint for the plugin

src/actions/verify-package.ts

@@ -21,6 +21,7 @@ import {
   validateScripts,
   validateTsConfig,
   validateSanityDependencies,
+  validateSrcIndexFile,
 } from './verify/validations'
 import {PackageJson, TsConfig} from './verify/types'
 import chalk from 'chalk'
@@ -37,6 +38,7 @@ export async function verifyPackage({basePath, flags}: {basePath: string; flags:
 
   await validation('packageName', async () => validatePackageName(packageJson))
   await validation('pkg-utils', async () => validatePkgUtilsDependency(packageJson))
+  await validation('srcIndex', async () => validateSrcIndexFile(basePath))
   await validation('scripts', async () => validateScripts(packageJson))
   await validation('module', async () => validateModule(packageJson))
   await validation('nodeEngine', async () => validateNodeEngine(packageJson))

src/actions/verify/validations.ts

@@ -421,3 +421,25 @@ export function validatePackageName(packageJson: PackageJson) {
     ]
   }
 }
+
+export async function validateSrcIndexFile(basePath: string) {
+  const paths = ['index.js', 'index.ts'].map((p) => path.join('src', p))
+  const allowedIndexFiles = paths.map((file) => path.join(basePath, file))
+
+  let hasIndex = false
+  for (const indexFile of allowedIndexFiles) {
+    hasIndex = hasIndex || (await fileExists(indexFile))
+  }
+  if (!hasIndex) {
+    return [
+      outdent`
+      Expected one of [${paths.join(', ')}] to exist.
+
+      @sanity/pkg-utils expects a non-jsx file to be the source entry-point for the plugin.
+      If you currently have JSX in your index file, extract it into a separate file and import it.
+      `,
+    ]
+  }
+
+  return []
+}

src/actions/verify/verify-common.ts

@@ -23,6 +23,7 @@ export const verifyPackageConfigDefaults = {
   'pkg-utils': true,
   nodeEngine: true,
   studioConfig: true,
+  srcIndex: true,
 } as const
 
 export type VerifyPackageConfig = Partial<Record<keyof typeof verifyPackageConfigDefaults, boolean>>

src/npm/package.ts

@@ -253,12 +253,7 @@ export async function writePackageJson(data: PackageData, options: InjectOptions
     license: license ? license.id : 'UNLICENSE',
   }
 
-  let source = flags.typescript ? './src/index.ts' : './src/index.js'
-  // account for existing (j|t)sx
-  if (prev?.source?.endsWith('x')) {
-    source += 'x'
-  }
-
+  const source = flags.typescript ? './src/index.ts' : './src/index.js'
   const manifest: PackageJson = {
     ...alwaysOnTop,
     // Use already configured values by default