generateSignedPostPolicyV4 returns incorrect URL (missing bucket path) when using STORAGE_EMULATOR_HOST

[7hokerz]

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A screenshot that you have tested with "Try this API".

Not applicable.

Link to the code that reproduces this issue. A link to a public Github Repository or gist with a minimal reproduction.

https://gist.github.com/7hokerz/9507293382bb71c91f9de9352f851268

A step-by-step description of how to reproduce the issue, based on the linked reproduction.

1. Set the STORAGE_EMULATOR_HOST environment variable (e.g., http://127.0.0.1:9199).
2. Call generateSignedPostPolicyV4(...).
3. Observe the url property in the response object.

A clear and concise description of what the bug is, and what you expected to happen.

Expected: url: 'http://127.0.0.1:9199/my-test-bucket'

When running in emulator mode, generateSignedPostPolicyV4 returns the base emulator host URL (e.g., http://127.0.0.1:9199) without appending the bucket name.

Observed: url: 'http://127.0.0.1:9199'

A clear and concise description WHY you expect this behavior, i.e., was it a recent change, there is documentation that points to this behavior, etc. **

the API endpoint in the emulator requires the bucket name to be part of the path (path-style) to route the request correctly.

referencing: https://docs.cloud.google.com/storage/docs/xml-api/post-object-forms

[7hokerz]

@Pulkit0110, As you seem to be the primary lead on this repository, Just wanted to check if you've had a chance to look at this yet.

[Pulkit0110]

Hi @7hokerz, I didn't get a chance to look at it. I'll try to review it asap