fix: disable linting on builds without a eslint configuration present

test/lib/next-modes/next-start.ts

@@ -4,6 +4,7 @@ import { NextInstance } from './base'
 import spawn from 'cross-spawn'
 import { Span } from 'next/dist/trace'
 import stripAnsi from 'strip-ansi'
+import { providesESLintConfiguration } from 'next-test-utils'
 
 export class NextStartInstance extends NextInstance {
   private _buildId: string
@@ -68,6 +69,13 @@ export class NextStartInstance extends NextInstance {
     if (this.buildCommand) {
       buildArgs = this.buildCommand.split(' ')
     }
+
+    // Disable linting if the directory provides an ESLint configuration. This
+    // prevents the project's eslint configuration from affecting the test.
+    if (!providesESLintConfiguration(this.testDir)) {
+      buildArgs.push('--no-lint')
+    }
+
     if (this.startCommand) {
       startArgs = this.startCommand.split(' ')
     }

test/lib/next-test-utils.ts

@@ -437,11 +437,43 @@ export function launchApp(
   )
 }
 
+/**
+ * Check if the directory provides an ESLint configuration.
+ *
+ * @param dir The directory to check.
+ * @returns Whether the directory provides an ESLint configuration.
+ */
+export function providesESLintConfiguration(dir: string) {
+  // If some of these files exist, we should not disable linting.
+  if (
+    ['.eslintrc.json', '.eslintrc.js', '.eslintrc'].some((file) =>
+      existsSync(path.join(dir, file))
+    )
+  ) {
+    return true
+  }
+
+  // If the `eslintConfig` field is present in the `package.json` file, we
+  // should not disable linting.
+  if (
+    existsSync(path.join(dir, 'package.json')) &&
+    readJson(path.join(dir, 'package.json')).eslintConfig
+  ) {
+    return true
+  }
+
+  return false
+}
+
 export function nextBuild(
   dir: string,
   args: string[] = [],
   opts: NextOptions = {}
 ) {
+  // Disable linting if the directory provides an ESLint configuration. This
+  // prevents the project's eslint configuration from affecting the test.
+  if (!providesESLintConfiguration(dir)) args.push('--no-lint')
+
   return runNextCommand(['build', dir, ...args], opts)
 }