createStubInstance - optional overrides

[ifrost]

Is your feature request related to a problem? Please describe.
Stubbing multiple properties require to write the var name multiple times, for example:

var stubbedObject = sinon.createStubInstance(MyClass);
stubbedObject.foo = sinon.stub().returns(2);
stubbedObject.bar = sinon.stub().callsFake(function() { return 1; });
stubbedObject.xyzzy = sinon.stub().returns('test');

Describe the solution you'd like
It'd be nice to have a shortcut syntax to provide optional overrides for createStubInstance, for example:

var stubbedObject = sinon.createStubInstance(MyClass, {
  foo: sinon.stub().returns(2),
  bar: sinon.stub().callsFake(function() { return 1; }),
  xyzzy: sinon.stub().returns('test')
});

Describe alternatives you've considered
The same result could be achieved with "with":

with (stubbedObject = sinon.createStubInstance(MyClass)) {
  foo = sinon.stub().returns(2);
  bar = sinon.stub().callsFake(function() { return 1; });
  xyzzy = sinon.stub().returns('test');
}

"with" expression, however, is marked as deprecated and probably it's not the best idea to use it.

Another alternative I thought about was to provide functions to give more flexibility:

var stubbedObject = sinon.createStubInstance(MyClass, {
  foo: function(stub, property) { 
    stub[property] = sinon.stub().returns(2);
  }
});

The version above would be easier to reuse. For example, sometimes we use fluent interfaces:

var stubbedObject = sinon.createStubInstance(MyClass);
stubbedObject.foo = sinon.stub().returnsThis();
stubbedObject.bar = sinon.stub().returnsThis();
stubbedObject.xyzzy = sinon.stub().returnsThis();

Could have even shorter syntax:

var returnsThis = function(stub, propertyName) {
  stub[propertyName] = sinon.stub().returnsThis();
}

var stubbedObject = sinon.createStubInstance(MyClass, {
  foo: returnsThis,
  bar: returnsThis,
  xyzzy: returnsThis
});

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[ifrost]

Hi, the PR for it is still open. Any chance of getting it merged?

[mroderick]

This was implemented in #1864 and published to NPM as sinon@6.3.0