From 110ffcca77d64e6de5a880dbf9e79fafd77088cb Mon Sep 17 00:00:00 2001
From: juergba <filodron@gmail.com>
Date: Thu, 12 Aug 2021 10:45:07 +0200
Subject: [PATCH] add new option 'fail-zero'

---
 lib/cli/run-option-metadata.js | 1 +
 lib/cli/run.js                 | 4 ++++
 lib/mocha.js                   | 1 +
 lib/runner.js                  | 2 ++
 4 files changed, 8 insertions(+)

diff --git a/lib/cli/run-option-metadata.js b/lib/cli/run-option-metadata.js
index 6bc6604018..984ad4b75e 100644
--- a/lib/cli/run-option-metadata.js
+++ b/lib/cli/run-option-metadata.js
@@ -35,6 +35,7 @@ const TYPES = (exports.types = {
     'diff',
     'dry-run',
     'exit',
+    'fail-zero',
     'forbid-only',
     'forbid-pending',
     'full-trace',
diff --git a/lib/cli/run.js b/lib/cli/run.js
index 06941fab8c..160315cd75 100644
--- a/lib/cli/run.js
+++ b/lib/cli/run.js
@@ -98,6 +98,10 @@ exports.builder = yargs =>
         requiresArg: true,
         coerce: list
       },
+      'fail-zero': {
+        description: 'Fail if no test(s) encountered',
+        group: GROUPS.RULES
+      },
       fgrep: {
         conflicts: 'grep',
         description: 'Only run tests containing this string',
diff --git a/lib/mocha.js b/lib/mocha.js
index 62a414a9fa..c501d91682 100644
--- a/lib/mocha.js
+++ b/lib/mocha.js
@@ -1025,6 +1025,7 @@ Mocha.prototype.run = function(fn) {
   const runner = new this._runnerClass(suite, {
     delay: options.delay,
     dryRun: options.dryRun,
+    failZero: options.failZero,
     cleanReferencesAfterRun: this._cleanReferencesAfterRun
   });
   createStatsCollector(runner);
diff --git a/lib/runner.js b/lib/runner.js
index 079ab3066d..388a8f394d 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -1044,6 +1044,8 @@ Runner.prototype.run = function(fn, opts = {}) {
   fn = fn || function() {};
 
   const end = () => {
+    if (!this.total && options.failZero) this.failures = 1;
+
     debug('run(): root suite completed; emitting %s', constants.EVENT_RUN_END);
     this.emit(constants.EVENT_RUN_END);
   };