[IMP] fastapi: httpx deprecated

[SirPyTech]

This change gets rid of the following warning that is logged in the latest test run:

StarletteDeprecationWarning: Using `httpx` with `starlette.testclient` is deprecated; install `httpx2` instead.

2026-07-06 09:17:28,300 432 WARNING odoo py.warnings: /opt/odoo-venv/lib/python3.10/site-packages/fastapi/testclient.py:1: StarletteDeprecationWarning: Using `httpx` with `starlette.testclient` is deprecated; install `httpx2` instead.
  File "/opt/odoo-venv/bin/coverage", line 6, in 
    sys.exit(main())
  File "/opt/odoo-venv/lib/python3.10/site-packages/coverage/cmdline.py", line 1164, in main
    status = CoverageScript().command_line(argv)
  File "/opt/odoo-venv/lib/python3.10/site-packages/coverage/cmdline.py", line 853, in command_line
    return self.do_run(options, args)
  File "/opt/odoo-venv/lib/python3.10/site-packages/coverage/cmdline.py", line 1043, in do_run
    runner.run()
  File "/opt/odoo-venv/lib/python3.10/site-packages/coverage/execfile.py", line 213, in run
    exec(code, main_mod.__dict__)
  File "/opt/odoo-venv/bin/odoo", line 8, in 
    odoo.cli.main()
  File "/opt/odoo/odoo/cli/command.py", line 66, in main
    o.run(args)
  File "/opt/odoo/odoo/cli/server.py", line 187, in run
    main(args)
  File "/opt/odoo/odoo/cli/server.py", line 180, in main
    rc = odoo.service.server.start(preload=preload, stop=stop)
  File "/opt/odoo/odoo/service/server.py", line 1433, in start
    rc = server.run(preload, stop)
  File "/opt/odoo/odoo/service/server.py", line 602, in run
    rc = preload_registries(preload)
  File "/opt/odoo/odoo/service/server.py", line 1333, in preload_registries
    registry = Registry.new(dbname, update_module=update_module)
  File "", line 2, in new
  File "/opt/odoo/odoo/tools/func.py", line 87, in locked
    return func(inst, *args, **kwargs)
  File "/opt/odoo/odoo/modules/registry.py", line 87, in new
    odoo.modules.load_modules(registry, force_demo, status, update_module)
  File "/opt/odoo/odoo/modules/loading.py", line 493, in load_modules
    processed_modules += load_marked_modules(cr, graph,
  File "/opt/odoo/odoo/modules/loading.py", line 374, in load_marked_modules
    loaded, processed = load_module_graph(
  File "/opt/odoo/odoo/modules/loading.py", line 284, in load_module_graph
    suite = loader.make_suite([module_name], 'at_install')
  File "/opt/odoo/odoo/tests/loader.py", line 76, in make_suite
    return OdooSuite(sorted(tests, key=lambda t: t.test_sequence))
  File "/opt/odoo/odoo/tests/loader.py", line 72, in 
    for m in get_test_modules(module_name)
  File "/opt/odoo/odoo/tests/loader.py", line 19, in get_test_modules
    results = _get_tests_modules(importlib.util.find_spec(f'odoo.addons.{module}'))
  File "/opt/odoo/odoo/tests/loader.py", line 30, in _get_tests_modules
    tests_mod = importlib.import_module(spec.name)
  File "/__w/rest-framework/rest-framework/fastapi/tests/__init__.py", line 2, in 
    from . import test_fastapi_demo
  File "/__w/rest-framework/rest-framework/fastapi/tests/test_fastapi_demo.py", line 16, in 
    from .common import FastAPITransactionCase
  File "/__w/rest-framework/rest-framework/fastapi/tests/common.py", line 20, in 
    from fastapi.testclient import TestClient
  File "/opt/odoo-venv/lib/python3.10/site-packages/fastapi/testclient.py", line 1, in 
    from starlette.testclient import TestClient as TestClient  # noqa

(from https://github.com/OCA/rest-framework/actions/runs/28780900500/job/85335980094#step:8:75)

[oerp-odoo]

One note using httpx2.

It has this dependency (idna>=3.18):
https://github.com/pydantic/httpx2/blob/95aebc3e482ea952f044ed77f9782713039bc106/src/httpx2/pyproject.toml#L50

But standard odoo does (idna==3.6 ; python_version >= '3.12'): https://github.com/odoo/odoo/blob/65dbcabcd243abf24d6d3c3788d2caff66485790/requirements.txt#L31

So you might need to resolve this.

[SirPyTech]

One note using httpx2.

It has this dependency (idna>=3.18): https://github.com/pydantic/httpx2/blob/95aebc3e482ea952f044ed77f9782713039bc106/src/httpx2/pyproject.toml#L50

But standard odoo does (idna==3.6 ; python_version >= '3.12'): https://github.com/odoo/odoo/blob/65dbcabcd243abf24d6d3c3788d2caff66485790/requirements.txt#L31

So you might need to resolve this.

Thanks for reporting this! I actually didn't know it.
Note that the Odoo requirement you linked is for 18.0 but this PR is for 16.0 so the requirement is actually

idna==2.10

(from https://github.com/odoo/odoo/blob/6aca71c9522b3be5b221847e8b005f233d3ea872/requirements.txt#L22)
that is even worse 😰

I don't know why Odoo is so strict about that requirement, but one thing I see is that in this repository's 18.0 we already have the requirement for httpx2:

rest-framework/test-requirements.txt

Line 2 in b13ff60

httpx2

Moreover this is a change only for the test environment (it changes test-requirements.txt) so maybe there are no big issues using it?
Let's see what the @OCA/rest-framework-maintainers think.

[oerp-odoo]

Yeah, I actually posted for Odoo 19 as I was setting up fastapi with that version and noticed issue with idna dependency. I assume odoo at some point tested that idna version and pinned to it as it was working for them. So they don't want to risk it and make it looser:). For testing environment I assume it should be fine as it probably just overwrites dependencies without trying to resolve like pip-tools or similar would do.