feat: allow 0-line files to be ignored in coverage output (#808)

Author: bcoe

index.js

@@ -451,8 +451,10 @@ NYC.prototype.report = function () {
 
   tree = libReport.summarizers.pkg(map)
 
-  this.reporter.forEach(function (_reporter) {
-    tree.visit(reports.create(_reporter), context)
+  this.reporter.forEach((_reporter) => {
+    tree.visit(reports.create(_reporter, {
+      skipEmpty: this.config.skipEmpty
+    }), context)
   })
 
   if (this._showProcessTree) {

lib/commands/report.js

@@ -29,6 +29,12 @@ exports.builder = function (yargs) {
       default: false,
       type: 'boolean'
     })
+    .option('skip-empty', {
+      describe: 'don\'t show empty files (no lines of code) in report',
+      default: false,
+      type: 'boolean',
+      global: false
+    })
     .example('$0 report --reporter=lcov', 'output an HTML lcov report to ./coverage')
 }
 

lib/config-util.js

@@ -215,6 +215,12 @@ Config.buildYargs = function (cwd) {
       default: './.nyc_output',
       global: false
     })
+    .option('skip-empty', {
+      describe: 'don\'t show empty files (no lines of code) in report',
+      default: false,
+      type: 'boolean',
+      global: false
+    })
     .pkgConf('nyc', cwd)
     .example('$0 npm test', 'instrument your tests with coverage')
     .example('$0 --require babel-core/register npm test', 'instrument your tests with coverage and transpile with Babel')

test/fixtures/cli/empty.js

@@ -937,6 +937,41 @@ describe('the nyc cli', function () {
       })
     })
   })
+
+  describe('skip-empty', () => {
+    it('does not display 0-line files in coverage output', (done) => {
+      const args = [
+        bin,
+        '--cache', 'false',
+        '--skip-empty', 'true',
+        process.execPath, './empty.js'
+      ]
+
+      const proc = spawn(process.execPath, args, {
+        cwd: fixturesCLI,
+        env: env
+      })
+
+      var stdout = ''
+      proc.stdout.on('data', function (chunk) {
+        stdout += chunk
+      })
+
+      proc.stdout.on('error', function (chunk) {
+        stdout += chunk
+      })
+
+      proc.on('close', function (code) {
+        code.should.equal(0)
+        stdoutShouldEqual(stdout, `
+        ----------|----------|----------|----------|----------|-------------------|
+        File      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
+        ----------|----------|----------|----------|----------|-------------------|
+        ----------|----------|----------|----------|----------|-------------------|`)
+        done()
+      })
+    })
+  })
 })
 
 function stdoutShouldEqual (stdout, expected) {