Added a flag (-R, --rejections) to make the test fail if an unhandled…

… Promise rejection happened during its execution (#658)

* Changed the npm scripts so they can be run in Windows (some tests keep failing though)

* Removed duplicate object key

* Added a flag (-R, --rejections) to make the test fail if an unhandled Promise rejection happened during its execution

* Added runner.js test case to cover the -R flag

lib/cli.js

@@ -280,6 +280,12 @@ internals.options = function () {
             description: 'file pattern to use for locating tests',
             default: null
         },
+        rejections: {
+            alias: 'R',
+            type: 'boolean',
+            description: 'fail test on unhandled Promise rejections',
+            default: null
+        },
         reporter: {
             alias: 'r',
             type: 'string',
@@ -343,7 +349,6 @@ internals.options = function () {
     };
 
     const defaults = {
-        verbose: false,
         paths: ['test'],
         coverage: false,
         debug: false,
@@ -357,6 +362,7 @@ internals.options = function () {
         'lint-errors-threshold': 0,
         'lint-warnings-threshold': 0,
         parallel: false,
+        rejections: false,
         reporter: 'console',
         shuffle: false,
         silence: false,
@@ -390,7 +396,7 @@ internals.options = function () {
     const keys = ['assert', 'colors', 'context-timeout', 'coverage', 'coverage-exclude',
         'coverage-path', 'debug', 'dry', 'environment', 'flat', 'globals', 'grep',
         'lint', 'lint-errors-threshold', 'lint-fix', 'lint-options', 'lint-warnings-threshold',
-        'linter', 'output', 'parallel', 'pattern', 'reporter', 'shuffle', 'silence',
+        'linter', 'output', 'parallel', 'pattern', 'rejections', 'reporter', 'shuffle', 'silence',
         'silent-skips', 'sourcemaps', 'threshold', 'timeout', 'transform', 'verbose'];
     for (let i = 0; i < keys.length; ++i) {
         if (argv.hasOwnProperty(keys[i]) && argv[keys[i]] !== undefined && argv[keys[i]] !== null) {

lib/runner.js

@@ -48,6 +48,7 @@ internals.defaults = {
     output: process.stdout,                         // Stream.Writable or string (filename)
     parallel: false,
     progress: 1,
+    rejections: false,
     reporter: 'console',
     shuffle: false,
 
@@ -517,6 +518,7 @@ internals.protect = function (item, state, callback) {
     let isFirst = true;
     let timeoutId;
     let countBefore = -1;
+    let failedWithUnhandledRejection = false;
 
     if (state.options.assert && state.options.assert.count) {
         countBefore = state.options.assert.count();
@@ -531,6 +533,11 @@ internals.protect = function (item, state, callback) {
     const finish = function (err, cause) {
 
         clearTimeout(timeoutId);
+        setImmediate(() => process.removeListener('unhandledRejection', promiseRejectionHandler));
+        if (failedWithUnhandledRejection) {
+            return;
+        }
+
         if (state.options.assert && state.options.assert.count) {
             item.assertions = state.options.assert.count() - countBefore;
         }
@@ -623,6 +630,16 @@ internals.protect = function (item, state, callback) {
     domain.on('error', onError);
     domains.push(domain);
 
+    const promiseRejectionHandler = function (reason) {
+
+        finish(reason, 'unhandledRejection');
+        failedWithUnhandledRejection = true;
+    };
+
+    if (state.options.rejections) {
+        process.on('unhandledRejection', promiseRejectionHandler);
+    }
+
     setImmediate(() => {
 
         domain.enter();

package.json

@@ -37,10 +37,10 @@
     "lab": "./bin/lab"
   },
   "scripts": {
-    "test": "./bin/_lab -fL -t 100 -m 3000",
+    "test": "node ./bin/_lab -fL -t 100 -m 3000",
     "posttest": "npm run lint-md",
-    "test-cov-html": "./bin/_lab -fL -r html -m 3000 -o coverage.html",
-    "lint": "./bin/_lab -d -f -L",
+    "test-cov-html": "node ./bin/_lab -fL -r html -m 3000 -o coverage.html",
+    "lint": "node ./bin/_lab -d -f -L",
     "lint-md": "eslint --config hapi --rule 'strict: 0, eol-last: 0' --plugin markdown --ext md  ."
   },
   "license": "BSD-3-Clause"

test/cli.js

@@ -1019,4 +1019,24 @@ describe('CLI', () => {
             done();
         });
     });
+
+    it('passes even with an unhandled Promise rejection in the code under test', (done) => {
+
+        RunCli(['test/cli_reject_promise/reject_promise.js'], (error, result) => {
+
+            expect(error).to.not.exist();
+            expect(result.code).to.equal(0);
+            done();
+        });
+    });
+
+    it('fails with an unhandled Promise rejection if the specified flag is set', (done) => {
+
+        RunCli(['test/cli_reject_promise/reject_promise.js', '-R'], (error, result) => {
+
+            expect(error).to.not.exist();
+            expect(result.code).to.equal(1);
+            done();
+        });
+    });
 });

test/cli_reject_promise/reject_promise.js

@@ -0,0 +1,28 @@
+'use strict';
+
+// Load modules
+
+const Code = require('code');
+const _Lab = require('../../test_runner');
+
+
+// Declare internals
+
+const internals = {};
+
+
+// Test shortcuts
+
+const lab = exports.lab = _Lab.script();
+const describe = lab.describe;
+const it = lab.it;
+const expect = Code.expect;
+
+
+describe('Test Promises', () => {
+
+    it('handles a Promise rejection', ( done ) => {
+        Promise.reject(new Error('Rejection!'));
+        done();
+    });
+});

test/runner.js

@@ -1824,4 +1824,24 @@ describe('Runner', () => {
             });
         });
     });
+
+    it('fails with an unhandled Promise rejection if the specified flag is set', (done) => {
+
+        const script = Lab.script();
+        script.test('handles a Promise rejection', (done) => {
+
+            Promise.reject(new Error('Rejection!'));
+            setImmediate(done);
+        });
+
+        Lab.execute(script, { rejections: true }, null, (err, notebook) => {
+
+            expect(err).not.to.exist();
+            expect(notebook.tests).to.have.length(1);
+            expect(notebook.failures).to.equal(1);
+            expect(notebook.tests[0].err.toString()).to.contain('Rejection!');
+            done();
+        });
+
+    });
 });