Pass options to middleware

[mrloop]

Useful if the middleware is expensive and should be optionally started
depending on ember-cli options.

For example ember serve and ember test use a path flag to specify
an existing ember build to use, without rebuilding. ember-cli-typescript
will add typechecking middleware regardless of ember using an existing
build, the typechecking middleware is not required. This can slow
down the initial request to express server significantly. Passing the
ember options to middleware will allow middleware to optionally enable
different features depending on options

See ember-cli-typescript making use of this here typed-ember/ember-cli-typescript#1148

[mrloop]

A couple of questions:

• not sure what test would be appropriate, check addonMiddlewares receives options in tests/unit/tasks/test-test.js?
• should the options passed to middlewares be transformed, be a subset? For example only pass {hasBuild: true} if original options contain path?

[rwjblue]

should the options passed to middlewares be transformed, be a subset? For example only pass {hasBuild: true} if original options contain path?

No, I don't think so. As mentioned in another comment the serverMiddleware hook already receives the unfettered options so this seems fine to me.

not sure what test would be appropriate, check addonMiddlewares receives options in tests/unit/tasks/test-test.js?

If possible, I'd setup a test that actually adds an addon that uses testemMiddleware and assert that it receives the options.

[rwjblue]

I think this will work on all of our supported Node versions:

Suggested change

	addons.push(function () {
	return addon.testemMiddleware.apply(addon, [].slice.call(arguments).concat([options]));
	});
	addons.push(function () {
	return addon.testemMiddleware(...arguments, options);
	});

[mrloop]

👍 have updated as suggested

[mrloop]

I'd setup a test that actually adds an addon that uses testemMiddleware and assert that it receives the options.

@rwjblue have added the suggested test. It configures a dummy test launcher for the test, so full stack is run, apart from the test apps tests.

[rwjblue]

Awesome, thank you!!!

[rwjblue]

I've updated the target of this PR and rebased against the beta branch. Should be ready to land once CI is green.