feat: nyc is being refactored to become the official Istanbul 1.0 bin (#286)

BREAKING CHANGE:

significant chunks of nyc's API have been reworked, to use the Istanbul 1.0 API: source-map support, instrumentation, the check-coverage command, etc.

Author: bcoe

README.md

@@ -1,13 +1,15 @@
 # nyc
 
-[![Build Status](https://travis-ci.org/bcoe/nyc.svg?branch=master)](https://travis-ci.org/bcoe/nyc)
-[![Coverage Status](https://coveralls.io/repos/bcoe/nyc/badge.svg?branch=)](https://coveralls.io/r/bcoe/nyc?branch=)
+[![Build Status](https://travis-ci.org/istanbuljs/nyc.svg?branch=master)](https://travis-ci.org/istanbuljs/nyc)
+[![Coverage Status](https://coveralls.io/repos/istanbuljs/nyc/badge.svg?branch=)](https://coveralls.io/r/istanbuljs/nyc?branch=master)
 [![NPM version](https://img.shields.io/npm/v/nyc.svg)](https://www.npmjs.com/package/nyc)
-[![Windows Tests](https://img.shields.io/appveyor/ci/bcoe/nyc/master.svg?label=Windows%20Tests)](https://ci.appveyor.com/project/bcoe/nyc)
+[![Windows Tests](https://img.shields.io/appveyor/ci/istanbuljs/nyc/master.svg?label=Windows%20Tests)](https://ci.appveyor.com/project/istanbuljs/nyc)
 [![Standard Version](https://img.shields.io/badge/release-standard%20version-brightgreen.svg)](https://github.com/conventional-changelog/standard-version)
 
-a code coverage tool built on [istanbul](https://www.npmjs.com/package/istanbul)
-that works for applications that spawn subprocesses.
+Istanbul's high-tech command line interface, with support for:
+
+* applications that spawn subprocesses.
+* ES2015 transforms, via [babel-plugin-istanbul](https://github.com/istanbuljs/babel-plugin-istanbul), or source-maps.
 
 ## Instrumenting Your Code
 
@@ -60,26 +62,27 @@ of the pre-transpiled code. You'll have to configure your custom require hook
 to inline the source map in the transpiled code. For Babel that means setting
 the `sourceMaps` option to `inline`.
 
-## Use babel-plugin__coverage__ for Better ES6/ES7 Support
+## Use with babel-plugin-istanbul for Better ES6/ES7 Support
 
-[`babel-plugin-__coverage__`](https://github.com/dtinth/babel-plugin-__coverage__) can be used to enable better first-class ES6 support.
+[`babel-plugin-istanbul`](https://github.com/istanbuljs/babel-plugin-istanbul) can be used to enable better first-class ES6 support.
 
-1. enable the `__coverage__` plugin:
+1. enable the `babel-plugin-istanbul` plugin:
 
   ```json
     {
       "babel": {
         "presets": ["es2015"],
         "env": {
           "test": {
-            "plugins": ["__coverage__"]
+            "plugins": ["istanbul"]
           }
         }
       }
     }
   ```
 
-  Note: With this configuration, the `__coverage__` will only be active when `NODE_ENV` or `BABEL_ENV` is `test`.
+  Note: With this configuration, the Istanbul instrumentation will only be active when `NODE_ENV` or `BABEL_ENV` is `test`.
+
   We recommend using the [`cross-env`](https://npmjs.com/package/cross-env) package to set these environment variables
   in your `package.json` scripts in a way that works cross-platform.
 
@@ -125,15 +128,13 @@ nyc --extension .jsx --extension .es6 npm test
 
 ## Checking Coverage
 
-nyc exposes istanbul's check-coverage tool. After running your tests with nyc,
-simply run:
+nyc can fail tests if coverage falls below a threshold.
+After running your tests with nyc, simply run:
 
 ```shell
 nyc check-coverage --lines 95 --functions 95 --branches 95
 ```
 
-This feature makes it easy to fail your tests if coverage drops below a given threshold.
-
 nyc also accepts a `--check-coverage` shorthand, which can be used to
 both run tests and check that coverage falls within the threshold provided:
 
@@ -239,17 +240,6 @@ can also be specified in the `nyc` stanza of your package.json:
 }
 ```
 
-## Configuring Istanbul
-
-Behind the scenes nyc uses [istanbul](https://www.npmjs.com/package/istanbul). You
-can place a `.istanbul.yml` file in your project's root directory to pass config
-setings to istanbul's code instrumenter:
-
-```yml
-instrumentation:
-  preserve-comments: true
-```
-
 ## Integrating With Coveralls
 
 [coveralls.io](https://coveralls.io) is a great tool for adding
@@ -285,7 +275,6 @@ That's all there is to it!
 
 > Note: by default coveralls.io adds comments to pull-requests on GitHub, this can feel intrusive. To disable this, click on your repo on coveralls.io and uncheck `LEAVE COMMENTS?`.
 
-
 ## Integrating with codecov
 
 `nyc npm test && nyc report --reporter=text-lcov > coverage.lcov && codecov`

bin/nyc.js

@@ -8,7 +8,6 @@ try {
   NYC = require('../index.js')
 }
 
-var path = require('path')
 var sw = require('spawn-wrap')
 var wrapper = require.resolve('./wrap.js')
 
@@ -64,7 +63,7 @@ var yargs = require('yargs/yargs')(process.argv.slice(2))
   })
   .option('cache', {
     alias: 'c',
-    default: false,
+    default: true,
     type: 'boolean',
     describe: 'cache instrumentation results for improved performance'
   })
@@ -108,19 +107,14 @@ var yargs = require('yargs/yargs')(process.argv.slice(2))
     type: 'boolean',
     description: 'should nyc handle instrumentation?'
   })
-  .option('instrumenter', {
-    default: './lib/instrumenters/istanbul',
-    type: 'string',
-    description: 'what library should be used to instrument coverage?'
-  })
   .help('h')
   .alias('h', 'help')
   .version()
   .pkgConf('nyc', process.cwd())
   .example('$0 npm test', 'instrument your tests with coverage')
-  .example('$0 --require babel-core/polyfill --require babel-core/register npm test', 'instrument your tests with coverage and babel')
+  .example('$0 --require --require babel-core/register npm test', 'instrument your tests with coverage and babel')
   .example('$0 report --reporter=text-lcov', 'output lcov report after running your tests')
-  .epilog('visit http://git.io/vTJJB for list of available reporters')
+  .epilog('visit https://git.io/voHar for list of available reporters')
 
 var argv = yargs.argv
 
@@ -141,12 +135,14 @@ if (argv._[0] === 'report') {
   // if instrument is set to false,
   // enable a noop instrumenter.
   if (!argv.instrument) argv.instrumenter = './lib/instrumenters/noop'
+  else argv.instrumenter = './lib/instrumenters/istanbul'
 
   var nyc = (new NYC({
     require: argv.require,
     include: argv.include,
     exclude: argv.exclude,
-    sourceMap: !!argv.sourceMap
+    sourceMap: !!argv.sourceMap,
+    instrumenter: argv.instrumenter
   }))
   nyc.reset()
 
@@ -180,12 +176,10 @@ if (argv._[0] === 'report') {
     var mainChildExitCode = process.exitCode
 
     if (argv.checkCoverage) {
-      checkCoverage(argv, function (done) {
-        process.exitCode = process.exitCode || mainChildExitCode
-
-        if (!argv.silent) report(argv)
-        return done()
-      })
+      checkCoverage(argv)
+      process.exitCode = process.exitCode || mainChildExitCode
+      if (!argv.silent) report(argv)
+      return done()
     } else {
       if (!argv.silent) report(argv)
       return done()
@@ -206,17 +200,12 @@ function report (argv) {
 }
 
 function checkCoverage (argv, cb) {
-  foreground(
-    process.execPath,
-    [
-      require.resolve('istanbul/lib/cli'),
-      'check-coverage',
-      '--lines=' + argv.lines,
-      '--functions=' + argv.functions,
-      '--branches=' + argv.branches,
-      '--statements=' + argv.statements,
-      path.resolve(process.cwd(), './.nyc_output/*.json')
-    ],
-    cb
-  )
+  process.env.NYC_CWD = process.cwd()
+
+  ;(new NYC()).checkCoverage({
+    lines: argv.lines,
+    functions: argv.functions,
+    branches: argv.branches,
+    statements: argv.statements
+  })
 }

build-self-coverage.js

@@ -3,8 +3,7 @@ var fs = require('fs')
 var path = require('path')
 
 ;[
-  'index.js',
-  'lib/source-map-cache.js'
+  'index.js'
 ].forEach(function (name) {
   var indexPath = path.join(__dirname, name)
   var source = fs.readFileSync(indexPath, 'utf8')