Apollo koa integration

[HriBB]

KoaJS apollo-server integration. All tests pass, but I still need to test it in a real-life application.

TODO:

• Update CHANGELOG.md with your change (include reference to issue & this PR)
• Make sure all of the significant new logic is covered by tests
• Rebase your changes on master so that they can be merged easily
• Make sure all tests and linter rules pass

[apollo-cla]

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[helfer]

@HriBB First of all, thanks a lot for the PR!

It looks like all the tests pass, but there are still some linter errors that you should fix:

src/integrations/expressApollo.test.ts[28, 26]: block is empty
src/integrations/hapiApollo.test.ts[31, 26]: block is empty
src/integrations/koaApollo.test.ts[16, 10]: Unused import: 'OperationStore'
src/integrations/koaApollo.ts[2, 13]: Unused import: 'koaBody'

For the empty blocks, you can just make the destroyApp argument optional and not pass it from express and hapi tests.

I'll add comments about the code inline.

[helfer]

Did afterEach not work? That would be preferable to adding the call explicitly in every test, I think.

[HriBB]

is this a good plan to introduce the alpha version of koa? will this alienate people who are using 1.x version of koa?

You are right, it's not a good plan, but I am not sure how to support both versions. Problem is that v2 uses a different syntax with async/await, where v1 uses generators/yield.

koa@1.x

app.use(function *(){
  this.body = 'Hello World';
});

koa@2.x

app.use(function(ctx){
  ctx.body = 'Hello World';
});

Not really sure how to tackle this. We could simply export two different versions such as apolloKoa and apolloKoa2. Not the best solution, but it could work, if there is a way to install both versions at once with npm. Is there?

[HriBB]

@helfer and @nnance I removed all unnecessary tests, fixed linter issues, made destroyApp() optional and moved it into afterEach() mocha hook. Please check it out and let me know what you think.

[helfer]

@HriBB thanks, that looks great!

Regarding the use of Koa 2 vs. 1, I found this interesting Medium post: https://medium.com/@l1ambda/why-you-should-use-koa-with-node-js-7c231a8174fa#.8h6opnbvy

The tldr is that 2.0 alpha is considered stable, but they won't officially recommend it until Node has native support for async/await and Koa 2.0 can be used without Babel.

I'd say we land this PR as it is, and consider rewriting it for Koa 1 if there are many requests for it.

[helfer]

@HriBB can you update the Changelog to mention Koa support? The format should be something along the lines of

• added Koa integration (@HriBB in Apollo koa integration #59)

Once that's done, I can merge the PR, and I think we'll be ready to officially release the new apollo server tomorrow or on Monday!

[HriBB]

@helfer done!

[HriBB]

I hope I did not break anything with merging upstream ...

[helfer]

Perfect, merged!