Add option fail-on-failing-test-suite to not fail test run if there w…

…ere no infrastructure problem

lib/cli/run-helpers.js

@@ -19,49 +19,62 @@ const PluginLoader = require('../plugin-loader');
 
 /**
  * Exits Mocha when tests + code under test has finished execution (default)
- * @param {number} code - Exit code; typically # of failures
+ * @param {number} failOnFailingTestSuite - Exit code; typically # of failures
  * @ignore
  * @private
  */
-const exitMochaLater = code => {
-  process.on('exit', () => {
-    process.exitCode = Math.min(code, 255);
-  });
+const exitMochaLater = failOnFailingTestSuite => {
+  return code => {
+    process.on('exit', () => {
+      if (failOnFailingTestSuite) {
+        process.exitCode = Math.min(code, 255);
+      } else {
+        process.exitCode = 0;
+      }
+    });
+  };
 };
 
 /**
  * Exits Mocha when Mocha itself has finished execution, regardless of
  * what the tests or code under test is doing.
- * @param {number} code - Exit code; typically # of failures
+ * @param {number} failOnFailingTestSuite - Exit code; typically # of failures
  * @ignore
  * @private
  */
-const exitMocha = code => {
-  const clampedCode = Math.min(code, 255);
-  let draining = 0;
-
-  // Eagerly set the process's exit code in case stream.write doesn't
-  // execute its callback before the process terminates.
-  process.exitCode = clampedCode;
-
-  // flush output for Node.js Windows pipe bug
-  // https://github.com/joyent/node/issues/6247 is just one bug example
-  // https://github.com/visionmedia/mocha/issues/333 has a good discussion
-  const done = () => {
-    if (!draining--) {
-      process.exit(clampedCode);
+const exitMocha = failOnFailingTestSuite => {
+  return code => {
+    let clampedCode;
+    if (failOnFailingTestSuite) {
+      clampedCode = Math.min(code, 255);
+    } else {
+      clampedCode = 0;
     }
-  };
+    let draining = 0;
 
-  const streams = [process.stdout, process.stderr];
+    // Eagerly set the process's exit code in case stream.write doesn't
+    // execute its callback before the process terminates.
+    process.exitCode = clampedCode;
 
-  streams.forEach(stream => {
-    // submit empty write request and wait for completion
-    draining += 1;
-    stream.write('', done);
-  });
+    // flush output for Node.js Windows pipe bug
+    // https://github.com/joyent/node/issues/6247 is just one bug example
+    // https://github.com/visionmedia/mocha/issues/333 has a good discussion
+    const done = () => {
+      if (!draining--) {
+        process.exit(clampedCode);
+      }
+    };
+
+    const streams = [process.stdout, process.stderr];
 
-  done();
+    streams.forEach(stream => {
+      // submit empty write request and wait for completion
+      draining += 1;
+      stream.write('', done);
+    });
+
+    done();
+  };
 };
 
 /**
@@ -111,19 +124,28 @@ exports.handleRequires = async (requires = [], {ignoredPlugins = []} = {}) => {
  * @param {Mocha} mocha - Mocha instance
  * @param {Options} [opts] - Command line options
  * @param {boolean} [opts.exit] - Whether or not to force-exit after tests are complete
+ * @param {boolean} [opts.failOnFailingTestSuite] - Whether or not to fail test run if tests were failed
  * @param {Object} fileCollectParams - Parameters that control test
  *   file collection. See `lib/cli/collect-files.js`.
  * @returns {Promise<Runner>}
  * @private
  */
-const singleRun = async (mocha, {exit}, fileCollectParams) => {
+const singleRun = async (
+  mocha,
+  {exit, failOnFailingTestSuite},
+  fileCollectParams
+) => {
   const files = collectFiles(fileCollectParams);
   debug('single run with %d file(s)', files.length);
   mocha.files = files;
 
   // handles ESM modules
   await mocha.loadFilesAsync();
-  return mocha.run(exit ? exitMocha : exitMochaLater);
+  return mocha.run(
+    exit
+      ? exitMocha(failOnFailingTestSuite)
+      : exitMochaLater(failOnFailingTestSuite)
+  );
 };
 
 /**
@@ -145,7 +167,11 @@ const parallelRun = async (mocha, options, fileCollectParams) => {
   mocha.files = files;
 
   // note that we DO NOT load any files here; this is handled by the worker
-  return mocha.run(options.exit ? exitMocha : exitMochaLater);
+  return mocha.run(
+    options.exit
+      ? exitMocha(options.failOnFailingTestSuite)
+      : exitMochaLater(options.failOnFailingTestSuite)
+  );
 };
 
 /**

lib/cli/run-option-metadata.js

@@ -35,6 +35,7 @@ const TYPES = (exports.types = {
     'diff',
     'dry-run',
     'exit',
+    'fail-on-failing-test-suite',
     'fail-zero',
     'forbid-only',
     'forbid-pending',

lib/cli/run.js

@@ -98,6 +98,11 @@ exports.builder = yargs =>
         requiresArg: true,
         coerce: list
       },
+      'fail-on-failing-test-suite': {
+        default: true,
+        description: 'Fail test run if tests were failed',
+        group: GROUPS.RULES
+      },
       'fail-zero': {
         description: 'Fail test run if no test(s) encountered',
         group: GROUPS.RULES

lib/mocha.js

@@ -162,6 +162,7 @@ exports.run = function(...args) {
  * @param {boolean} [options.delay] - Delay root suite execution?
  * @param {boolean} [options.diff] - Show diff on failure?
  * @param {boolean} [options.dryRun] - Report tests without running them?
+ * @param {boolean} [options.failOnFailingTestSuite] - Fail test run if tests were failed?
  * @param {boolean} [options.failZero] - Fail test run if zero tests?
  * @param {string} [options.fgrep] - Test filter given string.
  * @param {boolean} [options.forbidOnly] - Tests marked `only` fail the suite?
@@ -222,6 +223,7 @@ function Mocha(options = {}) {
     'delay',
     'diff',
     'dryRun',
+    'failOnFailingTestSuite',
     'failZero',
     'forbidOnly',
     'forbidPending',
@@ -926,6 +928,20 @@ Mocha.prototype.failZero = function(failZero) {
   return this;
 };
 
+/**
+ * Fail test run if tests were failed.
+ *
+ * @public
+ * @see [CLI option](../#-fail-on-failing-test-suite)
+ * @param {boolean} [failOnFailingTestSuite=true] - Whether to fail test run.
+ * @return {Mocha} this
+ * @chainable
+ */
+Mocha.prototype.failOnFailingTestSuite = function(failOnFailingTestSuite) {
+  this.options.failOnFailingTestSuite = failOnFailingTestSuite !== false;
+  return this;
+};
+
 /**
  * Causes tests marked `only` to fail the suite.
  *