/* eslint-env jest */ import { join } from 'path' import { PHASE_DEVELOPMENT_SERVER } from 'next/constants' const pathToConfig = join(__dirname, '_resolvedata', 'without-function') const pathToConfigFn = join(__dirname, '_resolvedata', 'with-function') // force require usage instead of dynamic import in jest // x-ref: https://github.com/nodejs/node/issues/35889 process.env.__NEXT_TEST_MODE = 'jest' describe('config', () => { let loadConfig: typeof import('next/dist/server/config').default beforeEach(async () => { // Reset the module cache to ensure each test gets a fresh config load // This is important because config.ts now has a module-level configCache jest.resetModules() // Dynamically import the module after reset to get a fresh instance const configModule = await import('next/dist/server/config') loadConfig = configModule.default }) it('Should get the configuration', async () => { const config = await loadConfig(PHASE_DEVELOPMENT_SERVER, pathToConfig) expect(config.customConfig).toBe(true) }) it('Should pass the phase correctly', async () => { const config = await loadConfig(PHASE_DEVELOPMENT_SERVER, pathToConfigFn) expect(config.phase).toBe(PHASE_DEVELOPMENT_SERVER) }) it('Should pass the defaultConfig correctly', async () => { const config = await loadConfig(PHASE_DEVELOPMENT_SERVER, pathToConfigFn) expect(config.defaultConfig).toBeDefined() }) it('Should assign object defaults deeply to user config', async () => { const config = await loadConfig(PHASE_DEVELOPMENT_SERVER, pathToConfigFn) expect(config.distDir).toEqual('.next') expect(config.onDemandEntries.maxInactiveAge).toBeDefined() }) it('Should pass the customConfig correctly', async () => { const config = await loadConfig(PHASE_DEVELOPMENT_SERVER, '', { customConfig: { customConfigKey: 'customConfigValue', }, }) expect(config.customConfigKey).toBe('customConfigValue') }) it('Should assign object defaults deeply to customConfig', async () => { const config = await loadConfig(PHASE_DEVELOPMENT_SERVER, '', { customConfig: { customConfig: true, onDemandEntries: { custom: true }, }, }) expect(config.customConfig).toBe(true) expect(config.onDemandEntries.maxInactiveAge).toBeDefined() }) it('Should allow setting objects which do not have defaults', async () => { const config = await loadConfig(PHASE_DEVELOPMENT_SERVER, '', { customConfig: { bogusSetting: { custom: true }, }, }) expect(config.bogusSetting).toBeDefined() expect(config.bogusSetting.custom).toBe(true) }) it('Should override defaults for arrays from user arrays', async () => { const config = await loadConfig(PHASE_DEVELOPMENT_SERVER, '', { customConfig: { pageExtensions: ['.bogus'], }, }) expect(config.pageExtensions).toEqual(['.bogus']) }) it('Should throw when an invalid target is provided', async () => { await expect(async () => { await loadConfig( PHASE_DEVELOPMENT_SERVER, join(__dirname, '_resolvedata', 'invalid-target') ) }).rejects.toThrow(/The "target" property is no longer supported/) }) it('Should throw an error when next.config.(js | mjs | ts) is not present', async () => { await expect( async () => await loadConfig( PHASE_DEVELOPMENT_SERVER, join(__dirname, '_resolvedata', 'missing-config') ) ).rejects.toThrow( /Configuring Next.js via .+ is not supported. Please replace the file with 'next.config.js'/ ) }) it('Should not throw an error when two versions of next.config.js are present', async () => { const config = await loadConfig( PHASE_DEVELOPMENT_SERVER, join(__dirname, '_resolvedata', 'js-ts-config') ) expect(config.__test__ext).toBe('js') }) it('Should not throw an error when next.config.ts is present', async () => { const config = await loadConfig( PHASE_DEVELOPMENT_SERVER, join(__dirname, '_resolvedata', 'typescript-config') ) expect(config.__test__ext).toBe('ts') }) })