Add output option to JSON reporter (mochajs#4131)

dorny · Mar 14, 2021 · 97b0b70 · 97b0b70
1 parent c6f874f
commit 97b0b70
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Showing 3 changed files with 180 additions and 98 deletions.
diff --git a/docs/index.md b/docs/index.md
@@ -1884,6 +1884,8 @@ Alias: `JSON`, `json`
 
 The JSON reporter outputs a single large JSON object when the tests have completed (failures or not).
 
+By default, it will output to the console. To write directly to a file, use `--reporter-option output=filename.json`.
+
 ![json reporter](images/reporter-json.png?withoutEnlargement&resize=920,9999){:class="screenshot" loading="lazy"}
 
 ### JSON Stream

diff --git a/lib/reporters/json.js b/lib/reporters/json.js
@@ -7,6 +7,10 @@
  */
 
 var Base = require('./base');
+var fs = require('fs');
+var path = require('path');
+var errors = require('../errors');
+var createUnsupportedError = errors.createUnsupportedError;
 var constants = require('../runner').constants;
 var EVENT_TEST_PASS = constants.EVENT_TEST_PASS;
 var EVENT_TEST_FAIL = constants.EVENT_TEST_FAIL;
@@ -38,6 +42,14 @@ function JSONReporter(runner, options) {
   var pending = [];
   var failures = [];
   var passes = [];
+  var output;
+
+  if (options && options.reporterOptions && options.reporterOptions.output) {
+    if (!fs || !fs.writeFileSync) {
+      throw createUnsupportedError('file output not supported in browser');
+    }
+    output = options.reporterOptions.output;
+  }
 
   runner.on(EVENT_TEST_END, function(test) {
     tests.push(test);
@@ -66,7 +78,15 @@ function JSONReporter(runner, options) {
 
     runner.testResults = obj;
 
-    process.stdout.write(JSON.stringify(obj, null, 2));
+    var json = JSON.stringify(obj, null, 2);
+    if (output) {
+      fs.mkdirSync(path.dirname(output), {recursive: true});
+      fs.writeFileSync(output, json);
+    } else if (typeof process === 'object' && process.stdout) {
+      process.stdout.write(json);
+    } else {
+      Base.consoleLog(json);
+    }
   });
 }
 

diff --git a/test/reporters/json.spec.js b/test/reporters/json.spec.js
@@ -1,144 +1,204 @@
 'use strict';
 
+var fs = require('fs');
 var sinon = require('sinon');
+var JSONReporter = require('../../lib/reporters/json');
 var Mocha = require('../../');
 var Suite = Mocha.Suite;
 var Runner = Mocha.Runner;
 var Test = Mocha.Test;
 
 describe('JSON reporter', function() {
+  var mocha;
   var suite;
   var runner;
   var testTitle = 'json test 1';
   var testFile = 'someTest.spec.js';
   var noop = function() {};
 
   beforeEach(function() {
-    var mocha = new Mocha({
+    mocha = new Mocha({
       reporter: 'json'
     });
     suite = new Suite('JSON suite', 'root');
     runner = new Runner(suite);
-    var options = {};
-    /* eslint no-unused-vars: off */
-    var mochaReporter = new mocha._reporter(runner, options);
-  });
-
-  beforeEach(function() {
-    sinon.stub(process.stdout, 'write').callsFake(noop);
   });
 
   afterEach(function() {
     sinon.restore();
   });
 
-  it('should have 1 test failure', function(done) {
-    var error = {message: 'oh shit'};
+  describe('test results', function() {
+    beforeEach(function() {
+      var options = {};
+      /* eslint no-unused-vars: off */
+      var mochaReporter = new mocha._reporter(runner, options);
+    });
 
-    var test = new Test(testTitle, function(done) {
-      done(new Error(error.message));
+    beforeEach(function() {
+      sinon.stub(process.stdout, 'write').callsFake(noop);
     });
 
-    test.file = testFile;
-    suite.addTest(test);
-
-    runner.run(function(failureCount) {
-      sinon.restore();
-      expect(runner, 'to satisfy', {
-        testResults: {
-          failures: [
-            {
-              title: testTitle,
-              file: testFile,
-              err: {
-                message: error.message
+    it('should have 1 test failure', function(done) {
+      var error = {message: 'oh shit'};
+
+      var test = new Test(testTitle, function(done) {
+        done(new Error(error.message));
+      });
+
+      test.file = testFile;
+      suite.addTest(test);
+
+      runner.run(function(failureCount) {
+        sinon.restore();
+        expect(runner, 'to satisfy', {
+          testResults: {
+            failures: [
+              {
+                title: testTitle,
+                file: testFile,
+                err: {
+                  message: error.message
+                }
               }
-            }
-          ]
-        }
+            ]
+          }
+        });
+        expect(failureCount, 'to be', 1);
+        done();
       });
-      expect(failureCount, 'to be', 1);
-      done();
     });
-  });
 
-  it('should have 1 test pending', function(done) {
-    var test = new Test(testTitle);
-    test.file = testFile;
-    suite.addTest(test);
-
-    runner.run(function(failureCount) {
-      sinon.restore();
-      expect(runner, 'to satisfy', {
-        testResults: {
-          pending: [
-            {
-              title: testTitle,
-              file: testFile
-            }
-          ]
-        }
+    it('should have 1 test pending', function(done) {
+      var test = new Test(testTitle);
+      test.file = testFile;
+      suite.addTest(test);
+
+      runner.run(function(failureCount) {
+        sinon.restore();
+        expect(runner, 'to satisfy', {
+          testResults: {
+            pending: [
+              {
+                title: testTitle,
+                file: testFile
+              }
+            ]
+          }
+        });
+        expect(failureCount, 'to be', 0);
+        done();
       });
-      expect(failureCount, 'to be', 0);
-      done();
     });
-  });
 
-  it('should have 1 test pass', function(done) {
-    const test = new Test(testTitle, () => {});
-
-    test.file = testFile;
-    suite.addTest(test);
-
-    runner.run(function(failureCount) {
-      expect(runner, 'to satisfy', {
-        testResults: {
-          passes: [
-            {
-              title: testTitle,
-              file: testFile,
-              speed: /(slow|medium|fast)/
-            }
-          ]
-        }
+    it('should have 1 test pass', function(done) {
+      const test = new Test(testTitle, () => {});
+
+      test.file = testFile;
+      suite.addTest(test);
+
+      runner.run(function(failureCount) {
+        expect(runner, 'to satisfy', {
+          testResults: {
+            passes: [
+              {
+                title: testTitle,
+                file: testFile,
+                speed: /(slow|medium|fast)/
+              }
+            ]
+          }
+        });
+        expect(failureCount, 'to be', 0);
+        done();
+      });
+    });
+
+    it('should handle circular objects in errors', function(done) {
+      var testTitle = 'json test 1';
+      function CircleError() {
+        this.message = 'oh shit';
+        this.circular = this;
+      }
+      var error = new CircleError();
+
+      var test = new Test(testTitle, function(done) {
+        throw error;
+      });
+
+      test.file = testFile;
+      suite.addTest(test);
+
+      runner.run(function(failureCount) {
+        sinon.restore();
+        expect(runner, 'to satisfy', {
+          testResults: {
+            failures: [
+              {
+                title: testTitle,
+                file: testFile,
+                err: {
+                  message: error.message
+                }
+              }
+            ]
+          }
+        });
+        expect(failureCount, 'to be', 1);
+        done();
       });
-      expect(failureCount, 'to be', 0);
-      done();
     });
   });
 
-  it('should handle circular objects in errors', function(done) {
-    var testTitle = 'json test 1';
-    function CircleError() {
-      this.message = 'oh shit';
-      this.circular = this;
-    }
-    var error = new CircleError();
+  describe("when 'reporterOptions.output' is provided", function() {
+    var expectedDirName = 'reports';
+    var expectedFileName = 'reports/test-results.json';
+    var options = {
+      reporterOptions: {
+        output: expectedFileName
+      }
+    };
+
+    beforeEach(function() {
+      /* eslint no-unused-vars: off */
+      var mochaReporter = new mocha._reporter(runner, options);
+    });
 
-    var test = new Test(testTitle, function(done) {
-      throw error;
+    beforeEach(function() {
+      // Add one test to suite to avoid assertions against empty test results
+      var test = new Test(testTitle, () => {});
+      test.file = testFile;
+      suite.addTest(test);
     });
 
-    test.file = testFile;
-    suite.addTest(test);
-
-    runner.run(function(failureCount) {
-      sinon.restore();
-      expect(runner, 'to satisfy', {
-        testResults: {
-          failures: [
-            {
-              title: testTitle,
-              file: testFile,
-              err: {
-                message: error.message
-              }
-            }
-          ]
-        }
+    describe('when file can be created', function() {
+      it('should write test results to file', function(done) {
+        var fsMkdirSync = sinon.stub(fs, 'mkdirSync');
+        var fsWriteFileSync = sinon.stub(fs, 'writeFileSync');
+
+        fsWriteFileSync.callsFake(function(filename, content) {
+          var expectedJson = JSON.stringify(runner.testResults, null, 2);
+          expect(expectedFileName, 'to be', filename);
+          expect(content, 'to be', expectedJson);
+        });
+
+        runner.run(function() {
+          fsMkdirSync.calledWith(expectedDirName, {recursive: true});
+          expect(fsWriteFileSync.calledOnce, 'to be true');
+          done();
+        });
+      });
+    });
+
+    describe('when run in browser', function() {
+      it('should throw unsupported error', function() {
+        sinon.stub(fs, 'writeFileSync').value(false);
+        expect(
+          () => new JSONReporter(runner, options),
+          'to throw',
+          'file output not supported in browser'
+        );
       });
-      expect(failureCount, 'to be', 1);
-      done();
     });
   });
 });