config: default support of .jsonc extension (#3753)

.gitignore

@@ -79,6 +79,7 @@ Session.vim
 out/
 .idea_modules/
 atlassian-ide-plugin.xml
+mocha.iml
 
 # SourceTree
 *_BACKUP_*

example/config/.mocharc.jsonc

@@ -0,0 +1,14 @@
+// This config file contains Mocha's defaults.
+// As you can see, comments are allowed.
+// This same configuration could be provided in the `mocha` property of your
+// project's `package.json`.
+{
+  diff: true,
+  "extension": ["js"],
+  "opts": "./test/mocha.opts",
+  "package": /* 📦 */ "./package.json",
+  "reporter": /* 📋 */ "spec",
+  "slow": 75.,
+  "timeout": /* ⏱ */ +2000,
+  "ui": "bdd",
+}

lib/cli/config.js

@@ -24,6 +24,8 @@ exports.CONFIG_FILES = [
   '.mocharc.js',
   '.mocharc.yaml',
   '.mocharc.yml',
+  '.mocharc.jsonc',
+  '.mocharc.json5',
   '.mocharc.json'
 ];
 
@@ -35,6 +37,7 @@ const parsers = (exports.parsers = {
   yaml: filepath =>
     require('js-yaml').safeLoad(fs.readFileSync(filepath, 'utf8')),
   js: filepath => require(filepath),
+  json5: filepath => require('json5').parse(fs.readFileSync(filepath, 'utf8')),
   json: filepath =>
     JSON.parse(
       require('strip-json-comments')(fs.readFileSync(filepath, 'utf8'))
@@ -56,6 +59,8 @@ exports.loadConfig = filepath => {
       config = parsers.yaml(filepath);
     } else if (ext === '.js') {
       config = parsers.js(filepath);
+    } else if (/\.json[5c]/.test(ext)) {
+      config = parsers.json5(filepath);
     } else {
       config = parsers.json(filepath);
     }

package.json

@@ -411,6 +411,7 @@
     "Sulabh Bista <sul4bh@gmail.com>",
     "Sune Simonsen <sune@we-knowhow.dk>",
     "Svetlana <39729453+Lana-Light@users.noreply.github.com>",
+    "Sylvain Stéphant <sstephant+github@gmail.com>",
     "Tapiwa Kelvin <tapiwa@munzwa.tk>",
     "Ted Yavuzkurt <hello@TedY.io>",
     "Teddy Zeenny <teddyzeenny@gmail.com>",
@@ -500,6 +501,7 @@
     "growl": "1.10.5",
     "he": "1.2.0",
     "js-yaml": "3.12.0",
+    "json5": "2.1.0",
     "log-symbols": "2.2.0",
     "minimatch": "3.0.4",
     "mkdirp": "0.5.1",

test/integration/config.spec.js

@@ -11,8 +11,10 @@ describe('config', function() {
     var configDir = path.join(__dirname, 'fixtures', 'config');
     var js = loadConfig(path.join(configDir, 'mocharc.js'));
     var json = loadConfig(path.join(configDir, 'mocharc.json'));
+    var jsonc = loadConfig(path.join(configDir, 'mocharc.jsonc'));
     var yaml = loadConfig(path.join(configDir, 'mocharc.yaml'));
     expect(js, 'to equal', json);
     expect(json, 'to equal', yaml);
+    expect(yaml, 'to equal', jsonc);
   });
 });

test/integration/fixtures/config/mocharc.jsonc

@@ -0,0 +1,7 @@
+// Comment
+{
+  require: ["foo", "bar"],
+  "bail": true,
+  "reporter": /* 📋 */ "dot",
+  "slow": +60,
+}

test/node-unit/cli/config.spec.js

@@ -21,6 +21,7 @@ describe('cli/config', function() {
       beforeEach(function() {
         sandbox.stub(parsers, 'yaml').returns(config);
         sandbox.stub(parsers, 'json').returns(config);
+        sandbox.stub(parsers, 'json5').returns(config);
         sandbox.stub(parsers, 'js').returns(config);
       });
 
@@ -57,6 +58,28 @@ describe('cli/config', function() {
         });
       });
 
+      describe('when supplied a filepath with .jsonc extension', function() {
+        const filepath = 'foo.jsonc';
+
+        it('should use the JSON5 parser', function() {
+          loadConfig('foo.jsonc');
+          expect(parsers.json5, 'to have calls satisfying', [
+            {args: [filepath], returned: config}
+          ]).and('was called times', 1);
+        });
+      });
+
+      describe('when supplied a filepath with .json5 extension', function() {
+        const filepath = 'foo.json5';
+
+        it('should use the JSON5 parser', function() {
+          loadConfig('foo.json5');
+          expect(parsers.json5, 'to have calls satisfying', [
+            {args: [filepath], returned: config}
+          ]).and('was called times', 1);
+        });
+      });
+
       describe('when supplied a filepath with .json extension', function() {
         const filepath = 'foo.json';