From 381c3d75f2779ce8b1da8b122043c1005f68f09b Mon Sep 17 00:00:00 2001
From: Mark Wiemer <markwiemer@outlook.com>
Date: Wed, 1 Oct 2025 17:01:23 -0700
Subject: [PATCH] Reapply "chore: cleanup references of --opts (#5402)" (#5404)

This reverts commit 221ff727455ab8a1ff69c0734c15ac9a187da594.
---
 .wallaby.js                           |  1 -
 lib/cli/run.js                        | 18 ++++++++----------
 test/integration/options/opts.spec.js | 23 -----------------------
 3 files changed, 8 insertions(+), 34 deletions(-)
 delete mode 100644 test/integration/options/opts.spec.js

diff --git a/.wallaby.js b/.wallaby.js
index 62573c2f97..9d5d4bf5fe 100644
--- a/.wallaby.js
+++ b/.wallaby.js
@@ -16,7 +16,6 @@ module.exports = () => {
         instrument: false
       },
       'package.json',
-      'test/opts/mocha.opts',
       'mocharc.yml',
       '!lib/browser/growl.js'
     ],
diff --git a/lib/cli/run.js b/lib/cli/run.js
index 561592b916..73a9832500 100644
--- a/lib/cli/run.js
+++ b/lib/cli/run.js
@@ -169,11 +169,15 @@ exports.builder = yargs =>
         group: GROUPS.RULES
       },
       'list-interfaces': {
-        conflicts: Array.from(ONE_AND_DONE_ARGS).filter(arg => arg !== "list-interfaces"),
+        conflicts: Array.from(ONE_AND_DONE_ARGS).filter(
+          arg => arg !== 'list-interfaces'
+        ),
         description: 'List built-in user interfaces & exit'
       },
       'list-reporters': {
-        conflicts: Array.from(ONE_AND_DONE_ARGS).filter(arg => arg !== "list-reporters"),
+        conflicts: Array.from(ONE_AND_DONE_ARGS).filter(
+          arg => arg !== 'list-reporters'
+        ),
         description: 'List built-in reporters & exit'
       },
       'no-colors': {
@@ -196,7 +200,8 @@ exports.builder = yargs =>
         group: GROUPS.RULES
       },
       'posix-exit-codes': {
-        description: 'Use POSIX and UNIX shell exit codes as Mocha\'s return value',
+        description:
+          "Use POSIX and UNIX shell exit codes as Mocha's return value",
         group: GROUPS.RULES
       },
       recursive: {
@@ -342,13 +347,6 @@ exports.builder = yargs =>
         );
       }
 
-      if (argv.opts) {
-        throw createUnsupportedError(
-          `--opts: configuring Mocha via 'mocha.opts' is DEPRECATED and no longer supported.
-          Please use a configuration file instead.`
-        );
-      }
-
       return true;
     })
     .middleware(async (argv, yargs) => {
diff --git a/test/integration/options/opts.spec.js b/test/integration/options/opts.spec.js
deleted file mode 100644
index d66db40603..0000000000
--- a/test/integration/options/opts.spec.js
+++ /dev/null
@@ -1,23 +0,0 @@
-'use strict';
-
-var invokeMocha = require('../helpers').invokeMocha;
-
-describe('--opts', function () {
-  it('should report deprecation', function (done) {
-    invokeMocha(
-      ['--opts', './test/mocha.opts'],
-      function (err, res) {
-        if (err) {
-          return done(err);
-        }
-        expect(
-          res,
-          'to have failed with output',
-          /'mocha.opts' is DEPRECATED/i
-        );
-        done();
-      },
-      'pipe'
-    );
-  });
-});