import stripAnsi from 'strip-ansi' import { nextTestSetup } from 'e2e-utils' describe('config validation - validation only runs once', () => { const { next } = nextTestSetup({ files: { 'pages/index.js': ` export default function Page() { return

hello world

} `, 'next.config.js': ` module.exports = { invalidOption: 'shouldTriggerValidation', anotherBadKey: 'anotherBadValue' } `, }, }) it('should validate config only once in root process', async () => { await next.fetch('/') const output = stripAnsi(next.cliOutput) const validationHeaderMatches = output.match( /Invalid next\.config\.js options detected:/g ) const validationHeaderCount = validationHeaderMatches ? validationHeaderMatches.length : 0 // Count occurrences of specific invalid option mentions const invalidOptionMatches = output.match(/invalidOption/g) const invalidOptionCount = invalidOptionMatches ? invalidOptionMatches.length : 0 const anotherBadKeyMatches = output.match(/anotherBadKey/g) const anotherBadKeyCount = anotherBadKeyMatches ? anotherBadKeyMatches.length : 0 // Expect validation to have occurred expect(output).toContain('Invalid next.config.js options detected') expect(output).toContain('invalidOption') expect(output).toContain('anotherBadKey') // Expect validation header to appear only once (not multiple times from different processes) expect(validationHeaderCount).toBe(1) // Each invalid option should also appear only once in the validation output expect(invalidOptionCount).toBe(1) expect(anotherBadKeyCount).toBe(1) }) })