Bug 3840: --forbid-only doesn't recognize it.only when before crashes

lib/interfaces/common.js

@@ -165,6 +165,7 @@ module.exports = function(suites, context, mocha) {
        * @returns {*}
        */
       only: function(mocha, test) {
+        if (mocha.options.forbidOnly) throw new Error('`.only` forbidden');
         test.markOnly();
         return test;
       },

test/integration/fixtures/options/forbid-only/only-before-each.fixture.js

@@ -0,0 +1,8 @@
+'use strict';
+
+describe('test marked with only and beforeEach has skip', function() {
+  beforeEach(function() {
+    this.skip();
+  });
+  it.only('only test', function() {});
+});

test/integration/fixtures/options/forbid-only/only-before.fixture.js

@@ -0,0 +1,8 @@
+'use strict';
+
+describe('test marked with only and before has skip', function() {
+  before(function() {
+    this.skip();
+  });
+  it.only('only test', function() {});
+});

test/integration/options/forbidOnly.spec.js

@@ -26,13 +26,22 @@ describe('--forbid-only', function() {
 
   it('should fail if there are tests marked only', function(done) {
     var fixture = path.join('options', 'forbid-only', 'only');
-    runMochaJSON(fixture, args, function(err, res) {
-      if (err) {
-        return done(err);
-      }
-      expect(res, 'to have failed with error', onlyErrorMessage);
-      done();
-    });
+    var spawnOpts = {stdio: 'pipe'};
+    runMocha(
+      fixture,
+      args,
+      function(err, res) {
+        if (err) {
+          return done(err);
+        }
+        expect(res, 'to satisfy', {
+          code: 1,
+          output: new RegExp(onlyErrorMessage)
+        });
+        done();
+      },
+      spawnOpts
+    );
   });
 
   it('should fail if there are tests in suites marked only', function(done) {
@@ -124,4 +133,44 @@ describe('--forbid-only', function() {
       }
     );
   });
+
+  it('should fail even if before has "skip"', function(done) {
+    var fixture = path.join('options', 'forbid-only', 'only-before');
+    var spawnOpts = {stdio: 'pipe'};
+    runMocha(
+      fixture,
+      args,
+      function(err, res) {
+        if (err) {
+          return done(err);
+        }
+        expect(res, 'to satisfy', {
+          code: 1,
+          output: new RegExp(onlyErrorMessage)
+        });
+        done();
+      },
+      spawnOpts
+    );
+  });
+
+  it('should fail even if beforeEach has "skip"', function(done) {
+    var fixture = path.join('options', 'forbid-only', 'only-before-each');
+    var spawnOpts = {stdio: 'pipe'};
+    runMocha(
+      fixture,
+      args,
+      function(err, res) {
+        if (err) {
+          return done(err);
+        }
+        expect(res, 'to satisfy', {
+          code: 1,
+          output: new RegExp(onlyErrorMessage)
+        });
+        done();
+      },
+      spawnOpts
+    );
+  });
 });