feat: supports custom client-side header configuration for API calls

[Littlezjh]

When creating a custom CozeAPI client using the following code snippet, the custom headers fail to be included in the outgoing requests. This PR adds support for passing the custom headers (e.g., X-Use-Ppe, X-Tt-Env) to the actual HTTP requests sent by the CozeAPI client:
client = coze.NewCozeAPI(
coze.NewTokenAuth(cozeConf.CozeAPIToken),
coze.WithBaseURL(cozeBaseUrl),
coze.WithHttpClient(&http.Client{Timeout: 600 * time.Second}),
coze.WithHeaders(
http.Header{
"X-Use-Ppe": []string{"1"},
"X-Tt-Env": []string{os.Getenv("SERVICE_ENV")},
}))

Summary by CodeRabbit

• Bug Fixes
  • Client-level default headers are now merged into outgoing requests so global defaults are included alongside request-specific headers; request headers can still override defaults.

[CLAassistant]

All committers have signed the CLA.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between e516d94 and 29f5d45.

📒 Files selected for processing (1)

• request.go

🚧 Files skipped from review as they are similar to previous changes (1)

• request.go

---

📝 Walkthrough

Walkthrough

Adds client-level default header merging to parseHeader in request.go: it iterates ins.headers and assigns the first value of each header into r.Headers before processing req.Headers, augmenting the request header set with global/client defaults.

Changes

Cohort / File(s)	Summary
Header merging in parser request.go	Inserted logic in parseHeader to iterate ins.headers and assign each header's first value into r.Headers prior to handling req.Headers, thereby introducing client/global default headers into the request.*

* The merge runs before request-specific headers are processed, so those can override these defaults.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 I tiptoe through headers, one by one,
Plucking the first like a morning sun,
I plant them in requests, a gentle start,
Then watch request headers play their part,
A hop, a merge — unity before the run! ✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'feat: supports custom client-side header configuration for API calls' accurately reflects the main change: adding support for custom headers in the CozeAPI client to be included in outgoing HTTP requests.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@request.go`:
- Around line 246-251: The current merge into r.Headers uses v[0] which can
panic if a header key has an empty slice (ins.headers[k] == nil or len==0), and
the merge order causes client-level headers to override per-request headers; fix
by first populating r.Headers with client defaults, then overlaying ins.headers
so request-level wins, and when iterating ins.headers (in the block using
ins.headers and r.Headers) check len(v) > 0 before reading v[0] (skip entries
with empty slices or handle them explicitly) to avoid panics; update the merge
logic that touches ins.headers and r.Headers accordingly.

---

ℹ️ Review info

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between c701843 and e516d94.

📒 Files selected for processing (1)

• request.go