From a9745f100322114fbe8f73e77a678be4e45a0ed4 Mon Sep 17 00:00:00 2001
From: Paul Roebuck <plroebuck@users.noreply.github.com>
Date: Thu, 3 May 2018 17:10:22 -0500
Subject: [PATCH 1/2] feat(bin/options.js): Add support for comment lines in
 "mocha.opts"

Modified code to strip comment lines, those beginning with a hash character ('#'), from "mocha.opts"
prior to processing its contents.

Fixes #3370
---
 bin/options.js                      | 1 +
 test/integration/regression.spec.js | 1 +
 test/mocha.opts                     | 5 +++++
 3 files changed, 7 insertions(+)

diff --git a/bin/options.js b/bin/options.js
index 60cbcd705e..a25a18e28e 100644
--- a/bin/options.js
+++ b/bin/options.js
@@ -32,6 +32,7 @@ function getOptions() {
   try {
     const opts = fs
       .readFileSync(optsPath, 'utf8')
+      .replace(/^#.*$/gm, '')
       .replace(/\\\s/g, '%20')
       .split(/\s/)
       .filter(Boolean)
diff --git a/test/integration/regression.spec.js b/test/integration/regression.spec.js
index e1f6b19dde..92f2223c7a 100644
--- a/test/integration/regression.spec.js
+++ b/test/integration/regression.spec.js
@@ -32,6 +32,7 @@ describe('regressions', function() {
     var processArgv = process.argv.join('');
     var mochaOpts = fs
       .readFileSync(path.join(__dirname, '..', 'mocha.opts'), 'utf-8')
+      .replace(/^#.*$/gm, '')
       .split(/[\s]+/)
       .join('');
     assert.notEqual(
diff --git a/test/mocha.opts b/test/mocha.opts
index c233b95260..c6f308ee28 100644
--- a/test/mocha.opts
+++ b/test/mocha.opts
@@ -1,6 +1,11 @@
+###
+### mocha.opts
+###
+
 --require ./test/setup
 --ui bdd
 --globals okGlobalA,okGlobalB
 --globals okGlobalC
 --globals callback*
 --timeout 200
+

From ddd15ed38385c24b7b88e2265d97cd948b003611 Mon Sep 17 00:00:00 2001
From: Paul Roebuck <plroebuck@users.noreply.github.com>
Date: Sat, 5 May 2018 10:26:34 -0500
Subject: [PATCH 2/2] docs(docs/index.md): Update "mocha.opts" documentation

Added information on file content, noting support for comment/blank lines.
---
 docs/index.md | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/docs/index.md b/docs/index.md
index a5acfc9945..b56610e043 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -1257,15 +1257,32 @@ The "HTML" reporter is what you see when running Mocha in the browser.  It looks
 
 ## `mocha.opts`
 
-Back on the server, Mocha will attempt to load `./test/mocha.opts` as a configuration file of sorts. The lines in this file are combined with any command-line arguments.  The command-line arguments take precedence.  For example, suppose you have the following `mocha.opts` file:
+Back on the server, Mocha will attempt to load `"./test/mocha.opts"` as a
+Run-Control file of sorts.
+
+Beginning-of-line comment support is available; any line _starting_ with a
+hash (#) symbol will be considered a comment. Blank lines may also be used.
+Any other line will be treated as a command-line argument (along with any
+associated option value) to be used as a default setting. Settings should be
+specified one per line.
+
+The lines in this file are prepended to any actual command-line arguments.
+As such, actual command-line arguments will take precedence over the defaults.
+
+For example, suppose you have the following `mocha.opts` file:
 
 ```sh
+# mocha.opts
+
   --require should
   --reporter dot
   --ui bdd
 ```
 
-This will default the reporter to `dot`, require the `should` library, and use `bdd` as the interface. With this, you may then invoke `mocha` with additional arguments, here enabling [Growl](http://growl.info) support, and changing the reporter to `list`:
+The settings above will default the reporter to `dot`, require the `should`
+library, and use `bdd` as the interface. With this, you may then invoke `mocha`
+with additional arguments, here enabling [Growl](http://growl.info/) support,
+and changing the reporter to `list`:
 
 ```sh
 $ mocha --reporter list --growl