feat: add support for --no-clean, to disable deleting raw coverage output (#558)

Author: bcoe

bin/nyc.js

@@ -38,8 +38,7 @@ if (argv._[0] === 'report') {
  else config.instrumenter = './lib/instrumenters/istanbul'
 
  var nyc = (new NYC(config))
- nyc.reset()
-
+ if (config.clean) nyc.reset()
  if (config.all) nyc.addAllFiles()
 
  var env = {

lib/config-util.js

@@ -64,7 +64,7 @@ Config.buildYargs = function (cwd) {
  default: 'coverage'
  })
  .option('temp-directory', {
- describe: 'directory from which coverage JSON files are read',
+ describe: 'directory to read raw coverage information from',
  default: './.nyc_output'
  })
  .option('show-process-tree', {
@@ -219,6 +219,17 @@ Config.buildYargs = function (cwd) {
  type: 'boolean',
  global: false
  })
+ .option('clean', {
+ describe: 'should the .nyc_output folder be cleaned before executing tests',
+ default: true,
+ type: 'boolean',
+ global: false
+ })
+ .option('temp-directory', {
+ describe: 'directory to output raw coverage information to',
+ default: './.nyc_output',
+ global: false
+ })
  .pkgConf('nyc', cwd || process.cwd())
  .example('$0 npm test', 'instrument your tests with coverage')
  .example('$0 --require babel-core/register npm test', 'instrument your tests with coverage and babel')

package.json

@@ -11,7 +11,7 @@
  "build": "node ./build-tests",
  "instrument": "node ./build-self-coverage.js",
  "test-integration": "tap -t120 --no-cov -b ./test/build/*.js && mocha --timeout=15000 ./test/src/nyc-bin.js",
- "test-mocha": "node ./bin/nyc --silent --temp-directory=./.self_coverage mocha ./test/nyc.js ./test/process-args.js",
+ "test-mocha": "node ./bin/nyc --no-clean --silent --temp-directory=./.self_coverage mocha ./test/nyc.js ./test/process-args.js",
  "report": "node ./bin/nyc --temp-directory ./.self_coverage/ -r text -r lcov report",
  "release": "standard-version"
  },