feat: Add support for yaml configuration file

README.md

@@ -341,7 +341,15 @@ modules should be required in the subprocess collecting coverage:
 
 ## Configuring `nyc`
 
-Any configuration options that can be set via the command line can also be specified in the `nyc` stanza of your package.json, or within a `.nycrc`, `.nycrc.json`, or `nyc.config.js` file:
+Any configuration options that can be set via the command line can also be specified in the `nyc` stanza of your package.json, or within a seperate configuration file - a variety of flavors are available:
+
+| File name       | File Association |
+|-----------------|------------------|
+| `.nycrc`        | JSON             |
+| `.nycrc.json`   | JSON             |
+| `.nycrc.yaml`   | YAML             |
+| `.nycrc.yml`    | YAML             |
+| `nyc.config.js` | CommonJS export  |
 
 **package.json:**
 

lib/config-util.js

@@ -21,14 +21,21 @@ Config.loadConfig = function (argv, cwd) {
   const rcOptions = [
     argv.nycrcPath || '.nycrc',
     '.nycrc.json',
+    '.nycrc.yml',
+    '.nycrc.yaml',
     'nyc.config.js'
   ]
   const rcPath = findUp.sync(rcOptions, { cwd: guessCWD(cwd) })
   let config = {}
 
   if (rcPath) {
-    if (rcPath.toLowerCase().endsWith('.js')) {
+    const rcExt = path.extname(rcPath.toLowerCase())
+    if (rcExt === '.js') {
       config = require(rcPath)
+    } else if (rcExt === '.yml' || rcExt === '.yaml') {
+      config = require('js-yaml').load(
+        fs.readFileSync(rcPath, 'utf8')
+      )
     } else {
       config = JSON.parse(
         fs.readFileSync(rcPath, 'utf-8')

package.json

@@ -80,6 +80,7 @@
     "istanbul-lib-report": "^2.0.7",
     "istanbul-lib-source-maps": "^3.0.5",
     "istanbul-reports": "^2.2.2",
+    "js-yaml": "^3.13.1",
     "make-dir": "^2.1.0",
     "merge-source-map": "^1.1.0",
     "resolve-from": "^4.0.0",

test/fixtures/cli/nycrc/.nycrc.yaml

@@ -0,0 +1,2 @@
+exclude:
+- ignore.js

test/fixtures/cli/nycrc/.nycrc.yml

@@ -0,0 +1,2 @@
+exclude:
+- ignore.js

test/nyc-integration.js

@@ -488,6 +488,48 @@ describe('the nyc cli', function () {
         })
       })
 
+      it('loads configuration from .nycrc.yml', function (done) {
+        var args = [bin, '--nycrc-path', './.nycrc.yml', process.execPath, './index.js']
+
+        var proc = spawn(process.execPath, args, {
+          cwd: cwd,
+          env: env
+        })
+
+        var stdout = ''
+        proc.stdout.on('data', function (chunk) {
+          stdout += chunk
+        })
+
+        proc.on('close', function (code) {
+          code.should.equal(0)
+          stdout.should.match(/SF:.*index\.js/)
+          stdout.should.not.match(/SF:.*ignore\.js/)
+          done()
+        })
+      })
+
+      it('loads configuration from .nycrc.yaml', function (done) {
+        var args = [bin, '--nycrc-path', './.nycrc.yaml', process.execPath, './index.js']
+
+        var proc = spawn(process.execPath, args, {
+          cwd: cwd,
+          env: env
+        })
+
+        var stdout = ''
+        proc.stdout.on('data', function (chunk) {
+          stdout += chunk
+        })
+
+        proc.on('close', function (code) {
+          code.should.equal(0)
+          stdout.should.match(/SF:.*index\.js/)
+          stdout.should.not.match(/SF:.*ignore\.js/)
+          done()
+        })
+      })
+
       it('allows .nycrc configuration to be overridden with command line args', function (done) {
         var args = [bin, '--exclude=foo.js', process.execPath, './index.js']