Throw an error upon unexpected termination of child process

lib/index.js

@@ -60,11 +60,15 @@ module.exports = function (ops, coverage) {
       that.emit('end');
     });
     // When done...
-    this._child.on('close', function (code) {
+    this._child.on('close', function (code, signal) {
       // If code is not zero (falsy)
       if (code) {
         that.emit('error', new PluginError('gulp-spawn-mocha', 'Mocha exited with code ' + code));
       }
+      // If code is null (process was terminated due to a signal)
+      if (code == null && signal) {
+        that.emit('error', new PluginError('gulp-spawn-mocha', 'Mocha was terminated by ' + signal));
+      }
       that.emit('end');
     });
     // Output to a file

test/index.test.js

@@ -100,6 +100,17 @@ describe('gulp-spawn-mocha tests', function () {
       stream.emit.should.be.calledWith('error', sinon.match.instanceOf(PluginError));
     });
 
+    it('should handle terminations from mocha', function () {
+      this.childOn.withArgs('close').yields(null, 'SIGTERM');
+      var stream = this.stream = mocha();
+      stream.write({path: 'foo'});
+      sinon.stub(stream, 'emit');
+      stream.emit.withArgs('error').returns();
+      stream.end();
+      this.childOn.should.be.calledTwice;
+      stream.emit.should.be.calledWith('error', sinon.match.instanceOf(PluginError));
+    });
+
     it('can output to a writable stream from a string argument', function () {
       var fakeStream = {};
       sinon.stub(fs, 'createWriteStream').returns(fakeStream);