fix: 9919 no exported config found

vercel · Jan 23, 2020 · 1418998 · 1418998
1 parent 53e9983
commit 1418998
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Showing 3 changed files with 26 additions and 0 deletions.
diff --git a/packages/next/next-server/server/config.ts b/packages/next/next-server/server/config.ts
@@ -228,6 +228,14 @@ export default function loadConfig(
       phase,
       userConfigModule.default || userConfigModule
     )
+
+    if (Object.keys(userConfig).length === 0) {
+      console.warn(
+        chalk.yellow.bold('Warning: ') +
+          'Detected next.config.js, no exported configuration found.'
+      )
+    }
+
     if (userConfig.target && !targets.includes(userConfig.target)) {
       throw new Error(
         `Specified target is invalid. Provided: "${

diff --git a/test/isolated/_resolvedata/no-export/next.config.js b/test/isolated/_resolvedata/no-export/next.config.js
@@ -0,0 +1,3 @@
+// eslint-disable-next-line no-lone-blocks
+{
+}
diff --git a/test/isolated/config.test.js b/test/isolated/config.test.js
@@ -108,4 +108,19 @@ describe('config', () => {
     )
     expect(config.__test__ext).toBe('js')
   })
+
+  it('Should log a warning when no exported configuration found', () => {
+    const spy = jest.spyOn(console, 'warn')
+
+    loadConfig(
+      PHASE_DEVELOPMENT_SERVER,
+      join(__dirname, '_resolvedata', 'no-export')
+    )
+
+    expect(spy.mock.calls[0][0]).toMatch(
+      'Detected next.config.js, no exported configuration found'
+    )
+
+    spy.mockRestore()
+  })
 })