Fix path generation for returned files for bash API

[cansik]

Description

As explained in #9049 (comment), the root_path calculation was limited to /gradio_api/queue/join requests, which led to incorrect string manipulation for calls to /gradio_api/call/predict (used by the Bash API).

In this PR, a new method is implemented to check whether the request was made to /gradio_api/queue/join or /gradio_api/call and then correctly calculates the root_path to subtract from the URL. This ensures that calls to any /gradio_api/call/* route are handled correctly (e.g., when using Gradio blocks).

Closes: #9049
Closes: #9317
Closes: #10839

[gradio-pr-bot]

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---

Install Gradio from this PR

pip install https://gradio-pypi-previews.s3.amazonaws.com/70fc8e55892c548ac3dce4f67ff2be06f9d83b49/gradio-5.22.0-py3-none-any.whl

Install Gradio Python Client from this PR

pip install "gradio-client @ git+https://github.com/gradio-app/gradio@70fc8e55892c548ac3dce4f67ff2be06f9d83b49#subdirectory=client/python"

Install Gradio JS Client from this PR

npm install https://gradio-npm-previews.s3.amazonaws.com/70fc8e55892c548ac3dce4f67ff2be06f9d83b49/gradio-client-1.13.1.tgz

Use Lite from this PR

<script type="module" src="https://gradio-lite-previews.s3.amazonaws.com/70fc8e55892c548ac3dce4f67ff2be06f9d83b49/dist/lite.js""></script>

[gradio-pr-bot]

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@gradio/core	patch
gradio	patch

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Fix path generation for returned files for bash API

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[cansik]

I am trying to fix the issues with the tests, but I don't understand why this test should be considered correct.

# input
(
    "https://www.gradio.app/playground/",
    f"{API_PREFIX}/",
    "http://www.gradio.app/",
    "http://www.gradio.app"
)

# test call
def test_get_root_url(
    request_url: str, route_path: str, root_path: str, expected_root_url: str
):

What is the expected behavior here? That https://www.gradio.app/playground/ turns into http://www.gradio.app by subtracting /gradio_api? This "works" only because {API_PREFIX}/ and playground/ have the same character length:

/gradio_api  
playground/

I think this is a case where the method should fail rather than pass. But would this impact Gradio's functionality?

For example, this input wouldn't work:

(
    "https://www.gradio.app/playground/",
    f"{API_PREFIX}/call/predict",
    "/playground",
    "https://www.gradio.app/playground",
)

# results in: 'https://w/playground'

@abidlabs What is the expected behaviour for the get_root_url method?

[cansik]

Also in the test_events.TestEvent.test_event_data the same issue seems to happen:

# inputs
root_path = ''
root_url = 'http://127.0.0.1:7860/gradio_api/run/predict'
route_path = '/gradio_api/api/predict'

# The two strings have the same lenght, that's why it worked till now...
/gradio_api/run/predict
/gradio_api/api/predict

[cansik]

I have now removed the exception from the get_root_url method since fixing it would take much longer and is out of scope for this PR. However, this seems to be a serious issue, and it feels like we are just lucky that strings tend to have the same lengths. I will create a separate issue to track and discuss this problem.

[abidlabs]

Taking a look at this now @cansik

[abidlabs]

Fantastic PR @cansik! I reviewed it and the changes look precisely correct. I also went ahead and updated the api docs snippet so that this closes #10839 as well

[abidlabs]

What is the expected behavior here? That https://www.gradio.app/playground/ turns into http://www.gradio.app by subtracting /gradio_api? This "works" only because {API_PREFIX}/ and playground/ have the same character length:

No the reason this test passes is because if a developer specifies a full URL as the root_path, it takes precedence over everything else and and the stripped version of that url is returned by the get_root_url. So in this case http://www.gradio.app/ -> http://www.gradio.app. Your PR doesn't affect this test.

[tqbl]

@cansik I'm having issues with this change. The get_request_url function is supposed to return the request URL, but when the X-Forwarded-Host header is present, the root URL ({scheme}://{host}) is returned instead. The latter causes get_api_call_path to raise an exception, because it's expecting the path component to be present in the URL.