feat: add support for per file coverage checking (#591)

README.md

@@ -153,6 +153,12 @@ nyc --check-coverage --lines 100 npm test
 
 The above check fails if coverage falls below 100%.
 
+To check thresholds on a per-file basis run:
+
+```shell
+nyc check-coverage --lines 95 --per-file
+```
+
 ## Running reports
 
 Once you've run your tests with nyc, simply run:
@@ -240,6 +246,7 @@ Any configuration options that can be set via the command line can also be speci
   "description": "These are just examples for demonstration, nothing prescriptive",
   "nyc": {
     "check-coverage": true,
+    "per-file": true,
     "lines": 99,
     "statements": 99,
     "functions": 99,

bin/nyc.js

@@ -97,5 +97,5 @@ function checkCoverage (argv, cb) {
     functions: argv.functions,
     branches: argv.branches,
     statements: argv.statements
-  })
+  }, argv['per-file'])
 }

index.js

@@ -441,21 +441,36 @@ NYC.prototype.showProcessTree = function () {
   console.log(processTree.render(this))
 }
 
-NYC.prototype.checkCoverage = function (thresholds) {
+NYC.prototype.checkCoverage = function (thresholds, perFile) {
   var map = this._getCoverageMapFromAllCoverageFiles()
-  var summary = map.getCoverageSummary()
+  var nyc = this
 
-  // ERROR: Coverage for lines (90.12%) does not meet global threshold (120%)
+  if (perFile) {
+    map.files().forEach(function (file) {
+      // ERROR: Coverage for lines (90.12%) does not meet threshold (120%) for index.js
+      nyc._checkCoverage(map.fileCoverageFor(file).toSummary(), thresholds, file)
+    })
+  } else {
+    // ERROR: Coverage for lines (90.12%) does not meet global threshold (120%)
+    nyc._checkCoverage(map.getCoverageSummary(), thresholds)
+  }
+
+  // process.exitCode was not implemented until v0.11.8.
+  if (/^v0\.(1[0-1]\.|[0-9]\.)/.test(process.version) && process.exitCode !== 0) process.exit(process.exitCode)
+}
+
+NYC.prototype._checkCoverage = function (summary, thresholds, file) {
   Object.keys(thresholds).forEach(function (key) {
     var coverage = summary[key].pct
     if (coverage < thresholds[key]) {
       process.exitCode = 1
-      console.error('ERROR: Coverage for ' + key + ' (' + coverage + '%) does not meet global threshold (' + thresholds[key] + '%)')
+      if (file) {
+        console.error('ERROR: Coverage for ' + key + ' (' + coverage + '%) does not meet threshold (' + thresholds[key] + '%) for ' + file)
+      } else {
+        console.error('ERROR: Coverage for ' + key + ' (' + coverage + '%) does not meet global threshold (' + thresholds[key] + '%)')
+      }
     }
   })
-
-  // process.exitCode was not implemented until v0.11.8.
-  if (/^v0\.(1[0-1]\.|[0-9]\.)/.test(process.version) && process.exitCode !== 0) process.exit(process.exitCode)
 }
 
 NYC.prototype._loadProcessInfos = function () {

lib/config-util.js

@@ -93,6 +93,10 @@ Config.buildYargs = function (cwd) {
           default: 0,
           description: 'what % of statements must be covered?'
         })
+        .option('per-file', {
+          default: false,
+          description: 'check thresholds per file'
+        })
         .example('$0 check-coverage --lines 95', "check whether the JSON in nyc's output folder meets the thresholds provided")
     })
     .option('reporter', {
@@ -195,6 +199,12 @@ Config.buildYargs = function (cwd) {
       description: 'should nyc detect and handle source maps?',
       global: false
     })
+    .option('per-file', {
+      default: false,
+      type: 'boolean',
+      description: 'check thresholds per file',
+      global: false
+    })
     .option('produce-source-map', {
       default: false,
       type: 'boolean',

test/nyc-bin.js

@@ -141,6 +141,27 @@ describe('the nyc cli', function () {
         done()
       })
     })
+
+    it('fails when the expected file coverage is below a threshold', function (done) {
+      var args = [bin, '--check-coverage', '--lines', '51', '--per-file', process.execPath, './half-covered.js']
+      var matcher = RegExp('ERROR: Coverage for lines \\(50%\\) does not meet threshold \\(51%\\) for .+/half-covered.js')
+
+      var proc = spawn(process.execPath, args, {
+        cwd: fixturesCLI,
+        env: env
+      })
+
+      var stderr = ''
+      proc.stderr.on('data', function (chunk) {
+        stderr += chunk
+      })
+
+      proc.on('close', function (code) {
+        code.should.not.equal(0)
+        stderr.trim().should.match(matcher)
+        done()
+      })
+    })
   })
 
   // https://github.com/bcoe/nyc/issues/190