chore(config): deprecate mode option (#8044)

packages/config/src/config/_common.js

@@ -1,6 +1,6 @@
 import capitalize from 'lodash/capitalize'
 import env from 'std-env'
-import { TARGETS, MODES } from '@nuxt/utils'
+import { TARGETS } from '@nuxt/utils'
 
 export default () => ({
   // Env
@@ -17,9 +17,10 @@ export default () => ({
   // Rendering
   ssr: true,
 
-  // TODO: remove in Nuxt 3
-  // Mode
-  mode: MODES.universal,
+  // Mode (deprecated)
+  mode: undefined,
+
+  // Modern
   modern: undefined,
 
   // Modules

packages/config/src/options.js

@@ -97,6 +97,18 @@ export function getNuxtConfig (_options) {
     options.target = 'server'
   }
 
+  // Deprecate Mode
+  if (options.mode) {
+    if ((options.mode === MODES.universal && options.ssr) || (options.mode === MODES.spa && !options.ssr)) {
+      consola.warn('`mode` option is deprecated. You can safely remove it from `nuxt.config`')
+    } else {
+      consola.warn('`mode` option is deprecated. Please use `ssr: true` for universal mode or `ssr: false` for spa mode and remove `mode` from `nuxt.config`')
+    }
+  } else {
+    // For backward compat we need default value
+    options.mode = MODES.universal
+  }
+
   // SSR root option
   if (options.ssr === false) {
     options.mode = MODES.spa

packages/config/test/config/__snapshots__/index.test.js.snap

@@ -241,7 +241,7 @@ Object {
     "server_error": "Server error",
     "server_error_details": "An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details.",
   },
-  "mode": "universal",
+  "mode": undefined,
   "modern": undefined,
   "modes": Object {
     "spa": Object {
@@ -617,7 +617,7 @@ Object {
     "server_error": "Server error",
     "server_error_details": "An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details.",
   },
-  "mode": "universal",
+  "mode": undefined,
   "modern": undefined,
   "modes": Object {
     "spa": Object {

packages/types/config/index.d.ts

@@ -50,6 +50,7 @@ export interface NuxtOptions extends Configuration {
   layoutTransition: Transition
   loading: NuxtOptionsLoading | false | string
   loadingIndicator: NuxtOptionsLoadingIndicator | false | string
+  /** @deprecated Use ssr option instead */
   mode: 'spa' | 'universal'
   target: 'server' | 'static'
   modern: 'client' | 'server' | boolean

test/fixtures/with-config/with-config.test.js

@@ -14,10 +14,11 @@ const hooks = [
 
 describe('with-config', () => {
   buildFixture('with-config', () => {
-    expect(consola.warn).toHaveBeenCalledTimes(7)
+    expect(consola.warn).toHaveBeenCalledTimes(8)
     expect(consola.fatal).toHaveBeenCalledTimes(0)
     expect(consola.warn.mock.calls).toMatchObject([
       ['`router.scrollBehavior` property is deprecated in favor of using `~/app/router.scrollBehavior.js` file, learn more: https://nuxtjs.org/api/configuration-router#scrollbehavior'],
+      ['`mode` option is deprecated. Please use `ssr: true` for universal mode or `ssr: false` for spa mode and remove `mode` from `nuxt.config`'],
       ['Unknown mode: unknown. Falling back to universal'],
       ['Invalid plugin mode (server/client/all): \'abc\'. Falling back to \'all\''],
       [{