Allow writing JSON reporter to write directly to file

.gitignore

@@ -21,3 +21,4 @@ yarn.lock
 *_REMOTE_*
 docs/_site
 docs/_dist
+output.json.tmp

docs/index.md

@@ -1100,6 +1100,8 @@ The "JSON" reporter outputs a single large JSON object when the tests have compl
 
 ![json reporter](images/reporter-json.png?withoutEnlargement&resize=920,9999){:class="screenshot"}
 
+By default, it will output to the console.  To write directly to a file, use `--reporter-options output=filename.json`.
+
 ### JSON Stream
 
 The "JSON stream" reporter outputs newline-delimited JSON "events" as they occur, beginning with a "start" event, followed by test passes or failures, and then the final "end" event.

lib/reporters/json.js

@@ -5,6 +5,9 @@
  */
 
 var Base = require('./base');
+var fs = require('fs');
+var mkdirp = require('mkdirp');
+var path = require('path');
 
 /**
  * Expose `JSON`.
@@ -18,7 +21,7 @@ exports = module.exports = JSONReporter;
  * @api public
  * @param {Runner} runner
  */
-function JSONReporter (runner) {
+function JSONReporter (runner, options) {
   Base.call(this, runner);
 
   var self = this;
@@ -27,6 +30,16 @@ function JSONReporter (runner) {
   var failures = [];
   var passes = [];
 
+  if (options && options.reporterOptions) {
+    if (options.reporterOptions.output) {
+      if (!fs.writeFileSync) {
+        throw new Error('file output not supported in browser');
+      }
+      mkdirp.sync(path.dirname(options.reporterOptions.output));
+      self.fileName = path.resolve(options.reporterOptions.output);
+    }
+  }
+
   runner.on('test end', function (test) {
     tests.push(test);
   });
@@ -54,7 +67,7 @@ function JSONReporter (runner) {
 
     runner.testResults = obj;
 
-    process.stdout.write(JSON.stringify(obj, null, 2));
+    self.write(JSON.stringify(obj, null, 2));
   });
 }
 
@@ -90,3 +103,18 @@ function errorJSON (err) {
   }, err);
   return res;
 }
+
+/**
+ * Write out the given data.
+ *
+ * @param {string} data
+ */
+JSONReporter.prototype.write = function (data) {
+  if (this.fileName) {
+    fs.writeFileSync(this.fileName, data);
+  } else if (typeof process === 'object' && process.stdout) {
+    process.stdout.write(data);
+  } else {
+    console.log(data);
+  }
+};

lib/reporters/xunit.js

@@ -38,7 +38,6 @@ exports = module.exports = XUnit;
  */
 function XUnit (runner, options) {
   Base.call(this, runner);
-
   var stats = this.stats;
   var tests = [];
   var self = this;

test/reporters/json.spec.js

@@ -1,63 +1,226 @@
 'use strict';
 
+var fs = require('fs');
+var path = require('path');
+var assert = require('assert');
 var Mocha = require('../../');
 var Suite = Mocha.Suite;
 var Runner = Mocha.Runner;
 var Test = Mocha.Test;
 
+var TEMP_FILE_PATH = path.resolve('output.json.tmp');
+
 describe('json reporter', function () {
   var suite, runner;
 
-  beforeEach(function () {
-    var mocha = new Mocha({
-      reporter: 'json'
-    });
-    suite = new Suite('JSON suite', 'root');
-    runner = new Runner(suite);
-    /* eslint no-unused-vars: off */
-    var mochaReporter = new mocha._reporter(runner);
+  after(function () {
+    if (fs.existsSync(TEMP_FILE_PATH)) {
+      fs.unlinkSync(TEMP_FILE_PATH);
+    }
   });
 
-  it('should have 1 test failure', function (done) {
-    var testTitle = 'json test 1';
-    var error = { message: 'oh shit' };
+  describe('with no output specified', function () {
+    beforeEach(function () {
+      var mocha = new Mocha({
+        reporter: 'json'
+      });
+      suite = new Suite('JSON suite', 'root');
+      runner = new Runner(suite);
+      /* eslint no-unused-vars: off */
+      var mochaReporter = new mocha._reporter(runner);
+    });
+    it('should have 1 test failure', function (done) {
+      var testTitle = 'json test 1';
+      var error = { message: 'oh shit' };
 
-    suite.addTest(new Test(testTitle, function (done) {
-      done(new Error(error.message));
-    }));
+      suite.addTest(new Test(testTitle, function (done) {
+        done(new Error(error.message));
+      }));
 
-    runner.run(function (failureCount) {
-      expect(failureCount).to.be(1);
-      expect(runner).to.have.property('testResults');
-      expect(runner.testResults).to.have.property('failures');
-      expect(runner.testResults.failures).to.be.an('array');
-      expect(runner.testResults.failures).to.have.length(1);
+      runner.run(function (failureCount) {
+        expect(failureCount).to.be(1);
+        expect(runner).to.have.property('testResults');
+        expect(runner.testResults).to.have.property('failures');
+        expect(runner.testResults.failures).to.be.an('array');
+        expect(runner.testResults.failures).to.have.length(1);
 
-      var failure = runner.testResults.failures[0];
-      expect(failure).to.have.property('title', testTitle);
-      expect(failure.err.message).to.equal(error.message);
-      expect(failure).to.have.property('err');
+        var failure = runner.testResults.failures[0];
+        expect(failure).to.have.property('title', testTitle);
+        expect(failure.err.message).to.equal(error.message);
+        expect(failure).to.have.property('err');
 
-      done();
+        done();
+      });
+    });
+
+    it('should have 1 test pending', function (done) {
+      var testTitle = 'json test 1';
+
+      suite.addTest(new Test(testTitle));
+
+      runner.run(function (failureCount) {
+        expect(failureCount).to.be(0);
+        expect(runner).to.have.property('testResults');
+        expect(runner.testResults).to.have.property('pending');
+        expect(runner.testResults.pending).to.be.an('array');
+        expect(runner.testResults.pending).to.have.length(1);
+
+        var pending = runner.testResults.pending[0];
+        expect(pending).to.have.property('title', testTitle);
+
+        done();
+      });
     });
   });
 
-  it('should have 1 test pending', function (done) {
-    var testTitle = 'json test 1';
+  describe('with output specified', function () {
+    beforeEach(function () {
+      var mocha = new Mocha({
+        reporter: 'json'
+      });
+      suite = new Suite('JSON suite', 'root');
+      runner = new Runner(suite);
+      /* eslint no-unused-vars: off */
+      var mochaReporter = new mocha._reporter(runner, { reporterOptions: { output: TEMP_FILE_PATH } });
+    });
+
+    it('should have 1 test failure', function (done) {
+      var testTitle = 'json test 1';
+      var error = { message: 'oh shit' };
+
+      suite.addTest(new Test(testTitle, function (done) {
+        done(new Error(error.message));
+      }));
+
+      runner.run(function (failureCount) {
+        expect(failureCount).to.be(1);
+        expect(runner).to.have.property('testResults');
+        expect(runner.testResults).to.have.property('failures');
+        expect(runner.testResults.failures).to.be.an('array');
+        expect(runner.testResults.failures).to.have.length(1);
+
+        var failure = runner.testResults.failures[0];
+        expect(failure).to.have.property('title', testTitle);
+        expect(failure.err.message).to.equal(error.message);
+        expect(failure).to.have.property('err');
+
+        var fileContents;
+        try {
+          fileContents = JSON.parse(fs.readFileSync(TEMP_FILE_PATH, 'utf-8'));
+        } catch (e) {
+          done(e);
+          return;
+        }
+
+        assert.deepEqual(fileContents, {
+          stats: {
+            suites: 1,
+            tests: 1,
+            passes: 0,
+            pending: 0,
+            failures: 1,
+            start: fileContents.stats.start,
+            end: fileContents.stats.end,
+            duration: fileContents.stats.duration
+          },
+          tests: [{
+            title: 'json test 1',
+            fullTitle: 'JSON suite json test 1',
+            duration: fileContents.tests[0].duration,
+            currentRetry: 0,
+            err: {
+              stack: fileContents.tests[0].err.stack,
+              message: 'oh shit'
+            }
+          }],
+          pending: [],
+          failures: [{
+            title: 'json test 1',
+            fullTitle: 'JSON suite json test 1',
+            duration: fileContents.failures[0].duration,
+            currentRetry: 0,
+            err: {
+              stack: fileContents.failures[0].err.stack,
+              message: 'oh shit'
+            }
+          }],
+          passes: []
+        });
+        assert.equal(Date.now() - new Date(fileContents.stats.start).getTime() < 10000, true);
+        assert.equal(Date.now() - new Date(fileContents.stats.end).getTime() < 10000, true);
+        assert.equal(typeof fileContents.stats.duration, 'number', JSON.stringify({ fileContents }, null, 2));
+        assert.equal(fileContents.stats.duration <= 30, true, JSON.stringify({ fileContents }, null, 2));
+        assert.equal(typeof fileContents.tests[0].duration, 'number', JSON.stringify({ fileContents }, null, 2));
+        assert.equal(fileContents.tests[0].duration <= 30, true, JSON.stringify({ fileContents }, null, 2));
+        assert.equal(typeof fileContents.failures[0].duration, 'number', JSON.stringify({ fileContents }, null, 2));
+        assert.equal(fileContents.failures[0].duration <= 30, true, JSON.stringify({ fileContents }, null, 2));
+        var errLines = fileContents.tests[0].err.stack.split('\n');
+        assert.equal(errLines[0], 'Error: oh shit', JSON.stringify({ fileContents }, null, 2));
+        var regexResult = /^ {4}at ((Object)|(Context))\.<anonymous> \(test(\/|\\)reporters(\/|\\)json\.spec\.js:92:14\)$/g.exec(errLines[1]);
+        assert.equal(!!regexResult, true, JSON.stringify({ regexResult, fileContents, line: errLines[1] }, null, 2));
+        errLines = fileContents.failures[0].err.stack.split('\n');
+        assert.equal(errLines[0], 'Error: oh shit', JSON.stringify({ fileContents }, null, 2));
+        regexResult = /^ {4}at ((Object)|(Context))\.<anonymous> \(test(\/|\\)reporters(\/|\\)json\.spec\.js:92:14\)$/g.exec(errLines[1]);
+        assert.equal(!!regexResult, true, JSON.stringify({ regexResult, fileContents, line: errLines[1] }, null, 2));
+
+        done();
+      });
+    });
+
+    it('should have 1 test pending', function (done) {
+      var testTitle = 'json test 1';
+
+      suite.addTest(new Test(testTitle));
+
+      runner.run(function (failureCount) {
+        expect(failureCount).to.be(0);
+        expect(runner).to.have.property('testResults');
+        expect(runner.testResults).to.have.property('pending');
+        expect(runner.testResults.pending).to.be.an('array');
+        expect(runner.testResults.pending).to.have.length(1);
 
-    suite.addTest(new Test(testTitle));
+        var pending = runner.testResults.pending[0];
+        expect(pending).to.have.property('title', testTitle);
 
-    runner.run(function (failureCount) {
-      expect(failureCount).to.be(0);
-      expect(runner).to.have.property('testResults');
-      expect(runner.testResults).to.have.property('pending');
-      expect(runner.testResults.pending).to.be.an('array');
-      expect(runner.testResults.pending).to.have.length(1);
+        var fileContents;
+        try {
+          fileContents = JSON.parse(fs.readFileSync(TEMP_FILE_PATH, 'utf-8'));
+        } catch (e) {
+          done(e);
+          return;
+        }
 
-      var pending = runner.testResults.pending[0];
-      expect(pending).to.have.property('title', testTitle);
+        assert.deepEqual(fileContents, {
+          stats: {
+            suites: 1,
+            tests: 1,
+            passes: 0,
+            pending: 1,
+            failures: 0,
+            start: fileContents.stats.start,
+            end: fileContents.stats.end,
+            duration: fileContents.stats.duration
+          },
+          tests: [{
+            title: 'json test 1',
+            fullTitle: 'JSON suite json test 1',
+            currentRetry: 0,
+            err: {}
+          }],
+          pending: [{
+            title: 'json test 1',
+            fullTitle: 'JSON suite json test 1',
+            currentRetry: 0,
+            err: {}
+          }],
+          failures: [],
+          passes: []
+        });
+        assert.equal(Date.now() - new Date(fileContents.stats.start).getTime() < 10000, true);
+        assert.equal(Date.now() - new Date(fileContents.stats.end).getTime() < 10000, true);
 
-      done();
+        done();
+      });
     });
   });
 });