fix(swift): ask for gzip so compressed responses decode

[ArnabChatterjee20k]

What does this PR do?

Fixes DecompressionError.inflationError(-3) in the Swift and Apple SDKs. It made every compressed response fail against an Appwrite server reached directly, without a proxy, and it was one of the three errors that stopped APNs registration on a device in #2000.

Root cause

• With decompression on and no Accept-Encoding of its own, NIO's NIOHTTPRequestDecompressor sends Accept-Encoding: deflate, gzip.
• Appwrite picks deflate, but sends a raw deflate stream (it starts 95 53 …). HTTP's deflate means a zlib stream, starting 78 ….
• NIO inflates deflate as zlib, so it fails with a data error (-3) on every compressed response.

Accept-Encoding: gzip           → Content-Encoding: gzip     1f 8b …  (gzip)
Accept-Encoding: deflate        → Content-Encoding: deflate  95 53 …  (raw deflate, not zlib)
Accept-Encoding: deflate, gzip  → Content-Encoding: deflate  ← what NIO asked for

Fix

• When the app hasn't set Accept-Encoding, the clients send Accept-Encoding: gzip, which every server and proxy decodes the same way. NIO then keeps the header instead of adding its own.
• On the Apple client this applies only while compression is on; setCompression(false) still sends identity.

The server half (answering deflate with a zlib stream) is worth fixing in Appwrite too, but older servers stay in use, so the clients shouldn't depend on it.

Test Plan

• Against a local Appwrite, account.get() 60 times with the generated Apple SDK on macOS:
  • before: 60/60 failed with inflationError(-3);
  • after: 0 failed.
• swift format lint --strict and swift build for the generated Swift (server) and Apple (client) SDKs.
• Generation suite and Twig lint.

Related PRs and Issues

• feat(apple): background push through APNs #2000 (device test: APNs registration failed with this error before reaching the API)

[hansi-codes]

🔵 Tier A · Mergeable after minor fixes

The implementation is narrow, but the gzip negotiation and compressed-response decoding behavior lacks automated regression coverage.

The Swift and Apple SDK templates now request gzip by default when callers have not supplied an Accept-Encoding header. The Apple client applies this only when response decompression is enabled, preserving its identity-encoding behavior when compression is disabled.

Verdict	New comments	Fixed	Still open
✅ Approved	1	0	0

	Finding	Where
🟡	Add a regression test for gzip response decoding	templates/swift/Sources/Client.swift.twig:338

Fix with agent prompt

### Issue 1
templates/swift/Sources/Client.swift.twig:338-339
**Add a regression test for gzip response decoding**

The Swift and Apple e2e suites exercise API calls, but none covers a compressed response or verifies this negotiation. Without an automated regression for the raw-deflate failure this change fixes, a later change could restore the failing behavior while the existing suites still pass.

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For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

📂 Walkthrough · 2

File	Change
templates/apple/Sources/Client.swift.twig	Adds gzip negotiation when compression is enabled and no encoding header is present.
templates/swift/Sources/Client.swift.twig	Adds gzip negotiation when no encoding header is present.

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_{Reviewed 0c3ea9b · Details · Comment @hansi-codes review to re-run, or mention @hansi-codes with a question.}

[hansi-codes]

🔵 Tier A · Looks good to merge. Summary

[hansi-codes]

Add a regression test for gzip response decoding

The Swift and Apple e2e suites exercise API calls, but none covers a compressed response or verifies this negotiation. Without an automated regression for the raw-deflate failure this change fixes, a later change could restore the failing behavior while the existing suites still pass.

Prompt To Fix With AI

This is a comment left during a code review.
Path: templates/swift/Sources/Client.swift.twig
Line: 338-339

Comment:
**Add a regression test for gzip response decoding**

The Swift and Apple e2e suites exercise API calls, but none covers a compressed response or verifies this negotiation. Without an automated regression for the raw-deflate failure this change fixes, a later change could restore the failing behavior while the existing suites still pass.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{🟡 Minor · testing · Reply if this doesn't apply.}