make query optional if all params are optional

[ysmood]

If all query parameters are optional we should use query?: { ... } instead of query: { ... }. Or when we use libs like openapi-fetch we have to always write an empty query: {} on the request like:

const res = await client.get('/do/{id}', {
  params: {
    query: {},
    path: {
        id: 123,
    },
  },
})

We expect to use code like this:

const res = await client.get('/do/{id}', {
  params: {
    path: {
        id: 123,
    },
  },
})

[drwpow]

Thanks for adding this; this already happens for the overall parameters object (#940) but it seems we didn’t mirror that behavior for query. I’m in favor of this just for better consistency.

Also, openapi-fetch is still immature, and types will improve over time (such as the behavior you just described—that will go away eventually). So I don’t want to make changes to this library just yet just to support openapi-fetch. But again, there’s reason for this to pass independently of that. But as openapi-fetch matures, it is a good public implementation of how openapi-typescript can be used, so eventually it will be good arguments to change this or that based on solid implementation.

[ysmood]

Sure, it's update to you to modify or closed this PR.

I think it's not just for openapi-fetch, we also need this feature for our custom lib to work better. I think other libs might also want this, it won't affect much on your refactoring. Also it's better to inline the behavior of query with parameters as you said.

I updated the tests and examples, the CI should pass now.