Missing query params in url when params option is set

[yanyongyu]

In version 0.28.0, query params are never merged.

import httpx

client = httpx.Client()
request = client.build_request(
    "GET", "https://httpbin.org/get?param=default", params={"foo": "bar"}
)
print(request.url)  # This will be `https://httpbin.org/get?foo=bar`

The query string in the request url will be ignored. It seems this is caused by the pr #3364. Params are replaced instead of merged when parsing.

httpx/httpx/_urlparse.py

Line 301 in 15e21e9

query = kwargs.get("query", url_dict["query"])

Related discussion #3428

[lovelydinosaur]

Params are replaced instead of merged when parsing.

This is exactly the behavior I would expect.
As I see it, the simplification in #3364 introduced a bugfix that we haven't documented in the release.

[yanyongyu]

I know providing both params and query in url is a bad practice. But this can be counterintuitive in some situations like:

import httpx

client = httpx.Client(params={"foo": "bar"})
request = client.build_request(
    "GET", "https://httpbin.org/get?param=default"
)
print(request.url)  # This will be `https://httpbin.org/get?foo=bar`

The params are provided in the client options. This will also replace the query in the url.

May be a warning can be raised when the replaced query is not empty?

httpx/httpx/_urlparse.py

Line 301 in 15e21e9

query = kwargs.get("query", url_dict["query"])

[lovelydinosaur]

Related issue... Client(params=...) is a not-good idea.

But this can be counterintuitive in some situations like

That is surprising behaviour, yes. I'd consider that a bug.

To the extent that we do currently support Client(params=...) we should probably? be merging those with any params=... passed by the user. Tho it's a bad pattern in the first place that we ideally could have avoided.

[yanyongyu]

Currently, as a workaround, we merge all the params by ourselves before passing to httpx. The code is clearer logically 😂 .